I tend to not get overly excited about new releases. The last few years have seen a lot of incremental upgrades that rarely blow me away. Usually, I end up thinking the new version of whatever is better than the last version. Not “rush out to the store and buy it” better, but “consider upgrading if you use it a lot” better.
Canon, though, (and Sigma) have hit some real home runs with optics lately, so I was a bit excited when Canon decided to upgrade one of their weaker lenses, the 16-35mm f/2.8, to a Mark III version. And if you don’t want to read the article I’ll summarize: rush out to the store and buy it.
As always, this isn’t a full review; that isn’t what I do. This is optical bench tests. Usually, I say stuff like ‘wait until the reviewers tell you how good it handles, and focuses and what the bokeh is like’ before you decide if it’s a good lens. Not this time. Optically this is such a big improvement that you just need to get it. If there are problems with that other stuff, then learn to deal with them.
Markus has made me a shiny new software tool that makes it easy for me to compare MTF curves between one lens and another, so I’m going to play with that for this post. As always, if you don’t speak MTF higher is better; dotted and solid lines of the same color close together is better; and on the horizontal axis “0” is the center of the image and “20” is very close to the corner. The rest is details.
At all focal lengths, the Mk III is clearly better than the Mk II both in center and off-axis sharpness. It also has far less astigmatism at both ends of the zoom range. This isn’t close at all. It’s a dramatic, easy-to-tell-in-your-photograph difference. The mark III version is dramatically better.
The Canon 16-35mm f/4 IS is a sharper lens at f/4 than the f/2.8 Mk II is at f/2.8. The mark III was so much better, though, that I thought it was worth making a direct comparison.
Olaf Optical Testing, 2016
Olaf Optical Testing, 2016
Giving up a stop of aperture is a huge disadvantage for MTF testing, but despite that, the 16-35mm f/2.8 Mk III is slightly better at f/2.8 than the 16-35mm f/4 IS is at f/4. There’s not a lot of difference, obviously, and I wouldn’t choose the f/2.8 Mk III purely on the basis of sharpness; the f/4 is less expensive and has IS. But if you need f/2.8, then there’s no sharpness penalty for going with the wider aperture lens.
Canon 16-35mm f/2.8 L Mk III vs Canon 24-70mm f/2.8 L Mk II at 24mm
The 16-35mm has been considered the weakest of the modern Canon zooms for some time. If I had an option for another lens, I generally went with the other lens. This comparison is one that I was really interested in since I tended to use the 16-35mm as a 16-22mm really and changed to a 24-70mm zoom whenever I could. The Canon 24-70mm f/2.8 Mk II is about as good as we see in a standard range zoom so I didn’t expect the 16-35mm Mk III would be as good but thought it might be reasonably close.
Olaf Optical Testing, 2016
The 24-70mm is, indeed, a bit sharper in the center. As we go away from the center, though, the 16-35mm actually is better by the middle of the frame. It might well be the better landscape/architectural lens at 24mm. I’m pretty surprised by this.
I hesitated to make this comparison, first because I know fanboys are going to start screaming online about it, and second because these aren’t really zooms of the same range. This is the middle of the Canon range but the extreme end of the Nikon. But for years now, the Nikon 14-24mm f/2.8 has been the gold standard of wide angle zooms and I was interested to see if Canon had finally caught up. They’ve done better than catch up.
Olaf Optical Testing, 2016
I can keep doing comparisons for pages, but the bottom line is clear. From an MTF standpoint, the Canon 16-35 f/2.8 Mk III is the best f/2.8 wide-angle zoom I’ve ever tested.
The sample variation for wide-angle zooms is usually pretty significant, but the new 16-35mm f/2.8 Mk III keeps that under pretty good control. Below are the variation spreads at 3 focal lengths (most zooms have one focal length at which variation is highest).
Olaf Optical Testing, 2016
Olaf Optical Testing, 2016
Olaf Optical Testing, 2016
The copy-to-copy variation for this lens is quite reasonable, but if you see it in your copy you’ll probably notice it at 35mm. Still, it clearly has less variation than the 16-35mm Mk II.
This summary is quick and simple. From a resolution standpoint, the Canon 16-35mm f/2.8 Mk III is the best f/2.8 wide-angle zoom available. You might be better served with the f/4 IS and some money in your pocket. There are also some very good wide-angle f/2.8 zooms available from third party manufacturers that are a lot less expensive and might offer more bang-for-the-buck. But if your style of photography needs the highest resolution you can get with a wide-angle lens, well this is it. I don’t use a wide-angle zoom all that often, but when I do, it will be this one.
I enjoy getting outdoors to backpack, hike, and camp. I love to find a quiet spot among the trees or in the desert and just sit and take in the quiet and beauty of the landscape. I find it therapeutic to get away from the noise distractions of the city and I also enjoy photographing those scenes and taking them home with me. Most of my trips center around photography and I’ve found that I’m more motivated to get out, exercise, and explore if the possibility taking home a great photo is there. And there is ALWAYS a great photo.
For me, landscape photography has always been a great opportunity to get out in the world, relax, and take some exceptional photos of the beauty that surrounds us. I’ve been involved with landscape photography, and the art of exploration for a number of years, and have learned a number of tips and tricks to help make the most of the tools I have. In the Army and recreationally I’ve been hiking, trekking, and exploring for 30 years and I’ve always taken a camera along. My first camera was a Minolta X-700 with (if I remember correctly) a Vivitar 28-210. These are some of my suggestions and tips when it comes to taking photos in the field.
Every trip is different, and I pack my camera bag or my backpack based on weight, time, distance, and subject. For example, if I’m backpacking and in addition to all my camping equipment, I’ll take very minimal photo gear to keep the weight in my pack below 40/45 pounds; a camera body, two lenses, and tripod. If I’m taking a day trip, I’ll take a camera bag with two bodies, three lenses, two tripods and other equipment. I also pack my bags based on subject. If I’m leaving late in the day and photographing the night sky, I’ll leave my medium zoom and bring along two bodies, two tripods, and two ultra-wide 14mm lenses.
Professional grade photo equipment is essential, and I use full frame DSLR bodies for a number of reasons. The first and foremost is high ISO performance. I do a lot of night work, which is some of my favorite types of landscapes, so having cleaner files at higher ISO’s is a must. If I’m exposing for the Milky Way, I want a sensor that will produce low ISO noise at ISO 5000/6400. Other reasons include better dynamic range, quality of depth of field, autofocus speed, dual memory card slots for backup, etc. Dual memory cards are especially important for me as I might be out for days taking thousands of RAW photos. Every time I fill up two cards, I swap the cards in the camera and then split up the memory cards in two different packs, bags, etc. I want to make absolutely sure I have my photos when I get home.
Likewise, my lens selections are based on convenience and expandability. With my three picks, I can cover all focal lengths from 14mm to 200mm. And If I take along a Nikon TC-20E III, I can extend the reach of my 70-200 to 400mm and the TC-20E III will maintain metering, autofocus, and VR capabilities.
So What is in my Camera Bag?
I tend to rent and buy the best lenses and DSLR bodies I can afford. The quality of the photo is the goal. But a tripod is the one piece of equipment I won’t spend a lot of money on. Why? 90 percent of the time I’m using a wide or ultra-wide lens and a 10th of a millimeter of movement on the tripod makes no difference in my shot. I also choose tripods with ballhead and a single knob to adjust the camera. Tripods with multiple adjustments make it difficult to work with the camera and tripod at night. Tripods are heavy and sometimes bulky and hard to manage with respect to backpacking and hiking. I don’t want to hike around hand carrying a heavy tripod for miles into the desert. Some photographers are all about finding the toughest and sturdiest tripod they can get their hands on and that’s fine if they want to carry it, but most lenses like my Tamron 24-70 f/2.8 and my Nikon 70-200 f/2.8 are image stabilized these days, so the VERY sturdy requirement of the tripod falls off the list at least for me. I stick with a medium or lower cost tripod for my landscapes when hiking and backpacking. I need to keep the weight down and it makes the trip more enjoyable. I’ve taken tens of thousands of photos using a 3.5 pound, 100 dollar tripod. I even use cheaper tripods with my carbon fiber time lapse slider with fantastic results. You also have to keep in mind this really doesn’t apply to bird photographers and others using long heavy pieces of glass. They do need a big sturdy tripod because of the weight of some lenses like the Canon 500mm f/4 and the requirement of the lens to be perfectly still when capturing a shot at 500mm or longer. So yes, a big sturdy tripod is a must for them, but I’m not backpacking or hiking with a beastly 500mm f/4 lens.
Nikon 14-24 f/2.8
This lens is heavy but exceptional optically. I’m a wide angle junkie and for me, this lens is required on every outing. I use it for both my night sky work and daylight snaps. I can always find a reason to photo anything at 14mm. It’s sharper corner to corner than any other Nikon mount at 14mm. It has very little distortion. Flair, ghosting and chromatic aberrations are all kept in check with Nikon’s Extra-low Dispersion glass and Nano Crystal Coat. Image quality is gorgeous and perfect for landscapes. There is a touch of dark corners (fall off) at f/2.8 but that starts to disappear at f/4, f/5.6, etc. AF is fast and constant on my Nikon D810. If you’re a Canon shooter the equally exceptional Canon 11-24 f/4 is a perfect option.
The front of the lens is an exposed protruding piece of glass protected by permanently attached petal hood and has no screw on filter options. However, there are a couple of manufacturers that make filter adapters for slide-in neutral density (ND), graduated ND, UV filters, and others.
Tamron 24-70 f/2.8 VC (Vibration Control)
I purchased this lens a year or so before Nikon released its version of the 24-70 f/2.8 VR (Vibration Reduction). Shooting handheld, I really wanted an image stabilized lens when I got into the 50mm – 70mm zoom range while working low light and the Tamron filled this for me. This lens does it all and I can use it for photographing landscapes, people, weddings, etc. The autofocus is not the fastest in the business, but I’m not shooting sports or birds with it. It does have a bit of fall off at f/2.8 but that’s easily fixed in post process and doesn’t both me. Sharpness is excellent. Not the best distortion performance but again easily adjusted in post. But at this price point, it’s perfect for me.
Ultimately, this is my number 2 lens choice when hiking or backpacking. It’s got enough zoom to capture that one scene that is just too far away for my 14-24mm or grabbing some great portraits of my friends and family while out hiking.
Nikon 70-200 f/2.8 VR (Replaced by the Nikon 70-200 f/2.8 VRII)
Fast aperture, Image stabilized, fast autofocus. It’s a bit heavy and I won’t pack this on long hiking trips, but I don’t mind carrying it a few miles on day trip in a backpack. As I mentioned earlier, I can mate this with a Nikon TC-20E III, extend my reach to 400mm all while maintaining metering, autofocus, and VR capabilities.
This lens is super versatile and is known as one of the best all around lenses on the market. It’s mated perfectly with my Nikon D750. With all this said, this is the last lens I will take on trips because I’m not a big zoom guy and sometimes it’s a bit heavy on longer hikes. If I want to photo something that’s far away, I’ll just hike over there. At 200mm, a quick 1/8th-mile hike will make a better photo with a 24-70mm.
Tamron 90mm f/2.8 Macro
Occasionally I’ll carry a Tamron 90mm f/2.8 macro for some interesting close-ups of flowers, insects, etc. This lens is pretty small, light and easy to pack for a day trip and it’s SUPER sharp. This lens has been around for a while and has been replaced by a new Image Stabilized version, but I’m holding on to mine because it’s been a workhorse for macros and is still going strong. If I had to do it all over again, I’d probably go with a smaller lens like the Nikon 60mm f/2.8 micro.
Most full frame professional cameras these days (for the most part) all have the same options and performance within reason. What it all boils down to is preference and the glass you’ve invested in. I’ve been shooting Nikon for years and love the menu system and the controls. Because most of my work is at night I have no problems finding exactly what I want within the menu system. I know what to expect from Nikon and I can make my changes quickly and start taking photos. This is not an extensive review of camera bodies. There are many of reviews on the internet for that. These are just a few items that are important to me when shooting in the field.
The Nikon D810 is a feature rich and fantastic general purpose platform. But a couple of my favorite things about this camera are the super clean images at its base ISO of 64, 36-megapixel image size, and sharpness. I find this perfect for landscapes because I can crop and blow up the image to print and see very little noise if any at all. I wouldn’t consider the dynamic range of the D810 as good as the D750, but then again the Nikon D750 has a newer image sensor. Unlike most DSLR’s the Nikon D810 has no optical low-pass and anti-aliasing bypassing, so the images will be sharper than cameras with those filters. I use this camera mostly for dusk and dawn shots, I find the images at ISO 5000/6400 for my night work are a bit noisier than the D750, but some will attribute this noise to the size of the sensor or the absence of optical low-pass and antialiasing filters. However, I do notice my night images are a bit sharper than the D750 – so it’s a tradeoff. Ultimately the difference is negligible. The Nikon D810 is a beefy camera and a bit bigger than the D750 but feels good in the hands. But if you’re shaving weight everywhere when backpacking, grab the D750. The Nikon D810 is a better choice than the Nikon D750 for working outdoors in semi or wet conditions because of its dust and moisture sealing. It’s not waterproof, but I’ve never had a problem with a bit of rain getting on the body. I even slipped and dropped it in the mud once. I cleaned everything off and it’s been fine. The Nikon D750 is sealed but not like the Nikon D810.
I do a lot of night work. I love to get out, set up my tent and then stay up all night running three cameras pointed at the night sky. I’ll come home from one overnight trip with 3 to 4000 photos or more. My night trips center on making time lapses. Sure, it’s awesome to take one really well-exposed photo of the Milky Way but it’s even better to see our Galaxy moving through the night sky. My go to camera for this is the Nikon D750. It’s hands down the best I’ve ever used with regard to high ISO performance and low noise at ISO 5000/6400. Some will argue that the new Canon 5D MK IV or the Sony A7RII or the A7SII are equally stellar or better, and they are in different respects. If I had one of the Sonys, I’d probably be running my night sky exposures at ISO 10,000 or higher to decrease my exposure time and thus achieve sharper images (because the stars are moving). Some call the Nikon D750 a dynamic range monster. It is and I love it. Why?
Fast autofocus, shadow and highlight recovery in RAW files
Excellent high ISO performance.
Ease of use. I really like the Nikon menu layout and I’m used to it
Tilt screen. Some done like tilt screens – but when I’m running this on my time lapse slider, it super useful
It’s smaller, lighter and more compact compared to other full frame DSLR’s
What are neutral density (ND) filters? Basically, I call them sunglasses for my lenses. I carry one variable ND that provides 2 to 8 stops of light control. This filter darkens the lens so you can, for example, expose for a few seconds in daylight at the lowest ISO and with the smallest aperture like f/22. ND’s and Variable ND’s are a must for the classic milky waterfall shot or the smooth looking beach shot with the waves coming in. I also carry a graduated ND. Half of the filter is neutral density and transitions gradually to clear. I use this filter to darken the sky at sunset so I can increase the exposure to reveal more of the foreground/landscape. ND and Graduated ND filters are also available in adapter holders for lenses that don’t have a screw on filter option. Although with modern cameras like the Nikon D750 I can easily achieve the same effect in Lightroom with the shadow and highlight sliders.
This is one of my favorite tools. Most but not all DSLR’s have one built in. But some don’t. I shoot a lot of time lapses at night and I use an intervalometer to take a photo every 10, 15, etc. seconds. I usually take about 450 photos and then put them together at 29.97 fps to make 15 second time lapse clips. This is also a handy tool if you have your camera on a tripod and are just taking random shots of a particular scene in low or no light.
Backpacks and Equipment Protection
For short day trips, I carry a water resistant Lowepro Fastpack 350. This pack has been bulletproof; I’ve had it for years and it’s still going strong. I love it for a number of reasons. It’s got a waist belt, chest strap, side slinging ability to grab equipment without taking off the pack, and adjustable inside organization partitions. These are a must for me as when I’m out trekking around. The waist belt holds the weight off my shoulders and the adjustable chest strap is perfect for keeping the shoulder straps close and tight but comfortable. If you are considering a day camera pack, get one with the above options. Like I said, this pack is water resistant to light rain, etc – but it’s not waterproof. With that said, I never shoot in the rain – There is just no point. Rain gets on the lens, equipment gets wet, etc. I’d rather wait until the rain passes and then shoot. However, I do carry tall kitchen plastic bags with me to protect the pack in case of a big downpour and I’m away from shelter, but that’s never happened.
Planning your Shots, Safety, and Other Equipment
Always plan your shoots. Ask yourself the following questions; Can I take a camera? Do I need a permit? What is the weather like? How long is the trail? Is the location safe? Do I need water? Should I take snacks? Is the place even open? Do I need to tell someone where I’m going (yes – always). Do I need a GPS:
Do I need a GPS?
If you get out and you’re hiking around enjoying the scenery and having the best time taking photos, you might get off the trail, lost, etc. If you’re not staying on clearly defined trails, always take a GPS and mark your parking area or start as a waypoint on the GPS. On second thought, you should always take one. If you haven’t used a GPS before, use it, practice with it and know it well before you venture out. I spend a lot of time hiking around wilderness areas and even in some National Parks like White Sands National Monument in New Mexico. You can become easily lost if you aren’t paying attention. And, as always, tell someone where you’re going.
I always take multiple red and white led lights and flashlights with me for both safety and seeing in the dark as I’m hiking or working with my equipment.
Unless you’re a seasoned hiker/explorer, if you can, hike and explore with friends or groups. Take handheld radios, cell phones and always stay together. Always take snacks and water. Food and water will keep you alert and sure-footed when hiking around on uneven ground.
It’s taken me years to figure out what I wanted on my trips with respect to bodies and lenses and I’m still learning and growing. Some will disagree with my setup and that’s fine. Everyone is different when choosing their equipment, setups and ultimately how they take their photos. But this is what’s really great about photography – it’s an art form and process and everyone will approach it differently.
Lastly, if I wanted just one body and one lens to take hiking that would achieve 98% of what I wanted to do? I’d probably go with a Nikon 28-300mm f/3.5-f/5.6 mated with a Nikon D750. Have fun and go explore.
I want to share with you guys a personal lens purchasing journey that I’ve been on for awhile now. My favorite genre of photography is travel photography; I love capturing landscapes, on location portraits, action sports, and general tourist stuff. It’s a very broad topic, and I want my camera gear to be as versatile as possible. When I travel, I like to be as light and compact as I can get. All my clothes, other personal items, and photography gear needs to fit into one carry-on size backpack. For those reasons my current camera platform of choice is the Sony Alpha series of E-mount cameras. Specifically the Sony A7rII, the A7sII, and the Sony A6300. I find these cameras are capable of capturing fantastic images while at the same time allowing me a much smaller footprint then gear I’ve carried in the past (cough* Canon 1D Mark IV * cough).
In addition to three cameras, I’ve discovered that I don’t want to carry more than four lenses with me at any given time. A wide angle zoom (currently the Sony 16-35mm f/4), a telephoto zoom (the Sony 70-200mm f/4), and two fast primes. The Zeiss Batis 85mm f/1.8 is one of those primes, but I am on a mission to find the best 50mm prime lens for my needs. This is no small task, but I’m determined to do just that.
More than a year ago I pre-ordered a copy of the Mitakon Speedmaster 50mm f/0.95, made by a company called Zhongyi, which I had never heard of before. On paper, this lens was exciting- a heavy duty, native E-mount lens with an exceptional maximum aperture. I was hoping this was going to be the poor man’s Leica Noctilux but in retrospect, I think I let my excitement get the better of me. It was a fun lens to shoot with at first, but over time I came to realize that there was something about the final images that I wasn’t in love with. On a recent trip out of the country, in a dark, rainy environment, I was photographing a family member, taking advantage of the Mitakon’s ability, with its large f-stop, to shoot in low light conditions. On the back of the camera, the images looked satisfactory, but when we went back indoors and loaded the photos on the computer, I was not pleased with what I saw. I realized I had passed the point of no return and it was time to discover if there was a better 50mm option out there for me.
It turned out that we rent a lot of other options in the “50mm lens that I can mount to a sony camera” category; roughly twenty-four, to be more accurate. As a Lensrentals employee, I already had a good bit of experience with many of these lenses but I had never taken the opportunity to examine them side by side, comparing their strengths and weaknesses, exploring their image quality, and ultimately try to figure out which lens best suited my needs Well, there’s no time like the present, right? We have to do what we have to do, so it’s officially time for a shootout.
I chose 13 of the best 50mm lens options that we carry for the Sony E-mount cameras. I chose the E-Mount, for a number of reasons. First, it’s highly adaptable. Sony has done an incredible job over the last couple years to tap into the market, but their lens lineups still have some catching up to do. Using the E-Mount allows me to not only test Sony and Zeiss lenses, but Sigma and Canon lenses as well. Second, Sony has been my go-to camera for a number of years now. With the small size of the Sony a7r II, I’m able to travel easier and still get great images. Also, however, Nikon lenses were not included in this comparison. That is simply because we can only present so much information in a single post, and we simply did not have time to also test a plethora of Nikon lenses along with the mix. However, we do have extensive information on Nikon lenses if you use the search above.
Now, before we get started, I’ll let it be known that this might not be as scientific as an article from Roger or anyone else who posts to this blog. This article, is real life examples as to how well each 50mm performs. I only used one copy of each lens, I only took a few photos with each setup, and my testing environments were less than lab quality. The reason I went this route is because the 13 lenses that I chose have more differences among them than they have similarities. Yes, they are all prime lenses with a roughly 50mm focal length and yes, I can mount them to an E-mount camera (albeit, some require an adaptor), but other than that they have very little in common with each other. The specs are all over the board. Different weights, sizes, filter threads, optics quality, brand, maximum aperture, focus abilities, and not to mention, price. There’s a huge difference in the costs between the most expensive and least expensive lenses in this group. Coming up with a fair way to judge which lens is actually “the best” would have been an impossible task from the start. So instead I chose to look at these lenses from the point of view of which is the right one for me and that means incorporating my opinion and shooting ability into the mix. So take anything you read here with a grain of salt, as it’s just one photographer’s viewpoint with emphasis on the qualities that are important to them.
Without further adieu, here’s the lineup and I’m going to skip ahead and mention the top pros and cons that I discovered while shooting these lenses. Keep in mind that my primary end goal is a lens for travel photography.
Compact, great IQ, fast AF, and the price is reasonably in the middle of the road
Filter size. 49mm means that I would have trouble sharing neutral density and polarizing filters with the other lenses in my kit. It’s not an insurmountable problem, more of an inconvenience. Also, in the studio tests, there seemed to be some small color shifts that would need to be addressed.
$700 is a pretty good price for a f/1.4 lens with autofocus.
Everything else. Seriously, I tried to give this lens the benefit of the doubt considering it was a new design that I wasn’t very familiar with but it fails in every category that’s important to me. It flared easily, had horrible colors, and even though I wasn’t purposefully testing autofocus, I did notice that its abilities were far from great.
Extremely compact, World renowned Zeiss image quality, and confidence inspiring weather sealing.
At f/2 it was one of the slowest lenses in the group, and there are other lenses in the same price range that offer a few more features. It’s a great little lens, but it’s not the only fish in the sea.
Camera Mount Type
Sony E (Full-Frame)
35mm Film / Full-Frame Digital Sensor
Sony NEX (APS-C)
On paper, the specs are impressive for this price point. It’s a lot of fun being able to shoot at f/0.95. The aperture allows you to shoot in the dark.
My personal copy of this lens seems to have declined in quality since I’ve owned it. It’s constantly a struggle to nail focus which leads me to believe that there’s a slightly decentered element or something else that needs to be repaired.
Maximum: f/.95 – 16
Camera Mount Type
Sony E (Full-Frame)
35mm Film / Full-Frame Digital Sensor
Sony NEX (APS-C)
Almost everything about this lens is awesome, and it has so much heritage that it’s exciting just to hold it.
The price is really steep, and the images have more chromatic aberration (i.e. purple fringe) then a lens in this price range should have, but I don’t think that’s anything new for anyone who has ever shot with this lens. The minimum focusing distance of 1 meter is limiting.
Super compact and it’s everything you’d expect from a Leica lens.
While the images were great I don’t think they were so far above the rest of the lens offering in this list that it justifies the price difference. This lens doesn’t make me want to buy it; it makes me want to rent it, along with a Leica camera body, and get the whole rangefinder experience. For me, kind of a “go big or go home” situation.
Phenomenal image quality, super sharp, beautiful skin tones. It’s the only lens in this group that makes me have irrational internal monologues like “who cares that it’s got a 39mm filter thread, using any filter or other glass in front of this thing is insulting.” Or “the price isn’t that bad. It would pay for itself in just a few years.”
Not just from these shoots, but I know this is a workhorse lens that’s very reliable. If I were moving from a Canon system and already owned this lens, I wouldn’t hesitate to use an adapter and keep this lens around.
With an adapter it’s bulky and clumsy plus it’s an older model lens that may get an upgrade soon so it wouldn’t be a sound investment considering I don’t already own it.
Camera Mount Type
35mm Film / Full-Frame Digital Sensor
Definitely one of the sharpest lenses in this test and very low distortion for a lens at that this price point. Distortion is not usually the first thing I notice when looking at studio images but in this case the lack of is noticeable.
You have to use an adapter. It would be so exciting if Sigma could make this lens in a native E-mount without losing any quality.
In my opinion, it produced the best images from the entire shootout. All of the “high resolving power” you hear about with this lens is not marketing hype. You can see it in the photos.
Size and weight. This thing is huge and in reality it was never a contender for me as a lens for travel photography.
Maximum: f/1.4 – 16
Camera Mount Type
35mm Film / Full-Frame Digital Sensor
Angle of View
Minimum Focus Distance
19.7″ (.50 m)
Not Specified By Manufacturer
Maximum Reproduction Ratio
Not Specified By Manufacturer
Not Specified By Manufacturer
Approx. 3.64 x 5.66″ (9.25 x 14.38 cm)
2.27 lb (1030 g)
I wanted to test these lenses in a way that made sense to me and see what I could discover from shooting with them that I couldn’t tell by just looking at the specs for each lens. I may have heard a rumor that one lens vignettes a lot, but what does “a lot” look like exactly? Or, “Lens A is more expensive, but it’s sharper than Lens B.” Ok, how much difference am I going to notice, what’s my acceptable level of sharpness, and how much am I willing to spend to get it? The best way for me to answer these questions for myself is to create some real world shooting scenarios where I can use all of the lenses in the same manner, in the same place, on the same subject and then look at the results.
So for the first test shoot, I went into the studio, fired up the strobe lights, got a model, filled the room with haze, and proceeded to set up a quick scene that I could photograph with all 13 lenses. I chose the camera settings ahead of time. Manual exposure, ISO 100, 1/125th of a second shutter speed, and an aperture of f/8. Now, a f/8 aperture should be near, or at, the “sweet spot” for each of these lenses. They should all be at their best level of performance regarding image quality, including sharpness, resolving power, color, and hopefully, a lack of any aberrations. When comparing so many different lenses, this is about as even of a playing field as it gets.
After framing the shot, I locked the camera off on a tripod and began shooting each lens 4 or 5 times, making sure to reset and manually focus between each shot. Lather, rinse and repeat. During this process, we attempted to keep an even level of haze in the room and our model, Stephanie, sought to keep the same pose throughout all of the shots. Like I said before, it may not be as scientific as an MTF chart, but neither is shooting.
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Back in the office, I loaded the images on the computer and culled through all of the shots, selecting the best example from each lens. I want to make these 13 raw files available for anyone that wants to download them and make their own comparisons because I know I’m not the only one that likes to pixel peep every once in awhile.
Here’s a full summary of what I saw after spending time zooming around each image, playing with lens profiles, and comparing various cropped portions of the photos: When just considering image quality, there’s not always a direct relationship between quality and price. The best example of this can be seen when comparing the Sony FE 50mm f/1.4 and the Sony FE 50mm f/1.8. The former is more than 7 times the cost of the Sony’s entry level prime. It’s IQ is virtually the same, it’s certainly not 7x better. That means the $1300 dollar price difference between the two is going towards something else, supposedly build quality, or maybe a better focus motor.
I discovered that my bias against Rokinon is justified and I don’t have to feel like a snob for not wanting to use it. While the Mitakon and Noctilux share a few similar traits, mainly their f/0.95 apertures, my copy of the Mitakon can’t hold a candle to anything with the name Leica on it. Even at f/8, it has terrible field curvature. The price tag associated with the APO-Summicron is about more than just sharpness. It has probably the best color tones of any lens that I have ever shot. I would not have been able to guess the price point of the Canon EF 50mm f/1.8 by just looking at the photo. Canon’s Nifty-Fifty is better than Sony’s and the Zeiss Otus produced the best overall image from all 13 lenses.
The second test shoot was designed to show how the lenses performed at their maximum aperture. This is more about the lens’s raw ability. Wide open, their strengths and weakness should become more apparent. Even if you don’t often shoot wide open or have the need for low light performance, the aperture number on the side of the lens is often a big part of what you’re paying for so it’s nice to know what you’ll get if you ever need to go there.
Just like in the studio, I created a scene that I thought would showcase several aspects of all of the lenses. We took our model outside and stuck her in between some low hanging branches from a tree down the street from our office. We framed the shot at a slight angle giving us elements in the foreground and the background so we’d see more differences in the depths of field these lenses created. This time, I shot in aperture priority mode and let the camera make the exposure decisions because there was a variety of different maximum apertures in our test group. Just like before though, we fired off 4-5 shots with each lens, making sure to reset and manually focus between each shot. Afterward, on the computer, I again culled through all of the images, selecting the best example from each lens.
Now for this test, I was using just natural light. The setting sun was behind the model, off-camera right, and I was using a Sunbounce reflector, camera left, to bounce fill light back into her face. Everything was going well until we got through all of the native e-mount lenses and were about to move onto the EF and M mount lens. I reached into my camera bag and realized that I had left the lens adapters back in the office. I ran back inside and got them but in the short time it took me to do that, the sun dipped just below the treeline and our lighting conditions changed drastically. If you download the raw files from this shoot, you’ll see what I mean.
At this point, I had a couple of options. Re-shoot all of the lenses in the new lighting conditions, chase the setting sun around, or reschedule the shoot. I did none of those things and here’s why: I decided at that time that I didn’t want to have to rely on an adapter in this lens decision. It’s one more piece of gear to keep up with, it’s another potential point of failure, and it’s more bulk. If I had an investment already in lenses from another camera platform, it might make more sense to use an adapter and continue to rely on the glass that I already had. In my case, I don’t need to do that as I’m building my lens kit from scratch.
Side note: In order to be as unbiased as possible when comparing this round of images, it’s helpful to try and remove any strong distractions such as the huge color and contrast differences between the two lighting scenarios. I chose to use some automated features in Adobe Lightroom to make this process easier. I went through each image and using the custom white balance tool selected the sclera, or white part, of Stephanie’s right eye. I then selected the entire group of photos and used the “Auto Tone” feature of Lightroom.
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To summarize these natural light test shots, you tend to get what you pay for in terms of sharpness which the exception being the Zeiss Otus as the clear winner, even though it’s actually not the most expensive lens in the group. Most other aspects remained the same as they were in the studio shoot. The Mitakon continued to yield bad colors as did the Rokinon which also proved to be the least sharp and exhibited horrible flaring even though we were not directly shooting into the sun. Also worth noting, the more expensive lenses nailed the focus point (the model’s left eye) much more consistently. I used the focus peaking in addition to the focus assist (zoom) features of the Sony A7rII but still struggled with the less expensive lenses. The only other real revelation was the tough reminder that the Leica Noctilux has a close focus distance of 1 meter, which happened to be exactly the distance that I was shooting at. Depth of field is related to focus distance, that means that even though the Leica has a f/0.95 aperture, lenses like the Canon EF 50mm f/1.2 are capable of achieving a more shallow depth of field image just because it can shoot closer to the subject.
So with the test results in mind, it’s time to look back at some of the specifications of each lens that I consider to be important.
3-Day Rental Price
Weight (in grams)
Min. Focus Distance (in cm)
Sony Planar T* FE 50mm f/1.4 ZA
Sony FE 50m f/1.8
Sony Sonnar T* FE 55mm f/1.8 ZA
Rokinon AF 50mm f/1.4
Zeiss Loxia 50mm f/2 Planar
Mitakon Zhongyi Speedmaster 50mm f/0.95
Leica Noctilux-M 50mm f/0.95 ASPH *
Leica Normal 50mm f/1.4 Summilux m *
Leica APO-Summicron-M 50mm f/2 ASPH *
Canon EF 50mm f/1.2L **
Canon EF 50mm f/1.8 STM **
Sigma 50mm f/1.4 DG HSM Art **
Zeiss 55mm f/1.4 Otus Distagon **
* requires the use of a Leica M lens to Sony E camera adapter
** requires use of a Canon EF lens to Sony E camera adapter
My purpose for doing these shoots was to find a 50mm prime lens, well suited for travel photography, to replace my quickly aging Mitakon Speedmaster. For me, the compact nature of both the Sony FE 55mm f/1.8 and the Zeiss Loxia 50mm f/2 Planar, combined with average price points but above average image quality means these are the two lenses I’m considering. Although the Loxia has a slight advantage over the Sony regarding image quality, I need to decide whether or not I’m willing to sacrifice that to gain great autofocus. I have a couple of trips coming up, including the Photo Plus Expo in New York, so I’m going to spend some more time renting and using both of these lenses before I decide which one finds a permanent home in my bag.
If you guys have any questions, comments, or arguments, leave them below.
Announced in the light of Photokina, came the continuation of the Canon 5d series with the latest from Canon, with the Canon 5d Mark IV. The announcement was met with mixed opinions, but like all camera announcements, there is no telling how great the system is until someone you trust gets their hands on the camera for themselves. Hopefully, here at Lensrentals.com, we’ve developed that relationship, and we’re here to test, and give a comprehensive review on the new flagship system from Canon – the Canon 5d Mark IV.
And before we get into the review, I want to mention that this review is broken into two pieces – photo and video. Since the release of the Canon 5d Mark II, Canon has been adding more and more video functionalities into the 5D series. The Canon 5D Mark IV is no exception, allowing for 4K video to be shot at 30fps. However, I specialize in photo far more than video, so I’ve gotten colleague and video tech for Lensrentals.com – Ryan Hill – to write a video portion of the review. These reviews are written independently, as not to skew each other’s opinions, and then welded together through the power of proofreading. So if there are any repeating mentions of features, be patient with us, as we’re just trying to get you the best opinion available on the new system.
As a photographer, the simple announcement of the Canon 5D Mark IV got me excited. This camera has been speculated for years and the Canon 5d Mark III, released in March 2012, was overdue for an update. With a new sensor, new autofocusing system, and something called Dual Pixel RAW, Canon has seemed to refresh their favorite line with a bunch of nice upgrades for the working photographer. So let’s just right into the features.
The new camera comes with an extensive list of features that are new when compared to the Mark III. Most important is the 30mp sensor that is powered by a Digic 6+ processor, allowing for up to 7fps of shooting in both normal and silent mode. Additionally, the Canon 5D Mark IV has built-in GPS and Wifi, allowing you to geotag your images with precision, and enable you to wirelessly transfer the images to a computer, tablet or phone, to post while on the go. When testing the Wifi, I found that it worked great at an event, allowing for small jpeg previews to be sent to an iPad at pretty rapid pacing. While the tech isn’t quite there, I imagine tethering wirelessly on commercial shoots is only a few years away.
It also sports a new autofocus system, which is compared to the Canon 1DX Mark II’s system, which I found to be incredible. My experiences with the system weren’t as elaborate as tracking fast moving objects, though I have no doubts that the camera would handle it with ease. Perhaps this itself is the biggest improvement over the Canon 5d Mark III. With each new system, Canon has managed to improve the focusing system, and this focus system might be the best in camera systems today. With an autofocus system that works exceptionally at tracking for both photo and video, it’s hard to believe that in a few years, this system will likely be obsolete. Like all new innovative technologies – I can’t see how this can be improved, but perhaps that is why I’m a consumer and not an engineer.
And the biggest announcement in the features came in the form of Dual Pixel RAW, which allows you to micro focus your images after the fact. In practicality, it’s brilliant. How often have you found that one winner in your frames, only to see that you have some slight back focusing? That said, it’s all theory now, as Adobe and Capture One have not added the feature into their RAW software, so the feature isn’t enabled unless you’re using Canon’s gaudy software. So while I wasn’t able to test this feature (yet), I’m looking forward to seeing how it works when it becomes more readily available.
However, I really think the biggest improvements come in the unspoken features – that may not be revolutionary, but allow for some neat little tricks that help you shoot faster, and more efficiently. Here are a few of my favorites.
The Unspoken Features
Much to my surprise, the Canon 5D Mark IV comes with a bunch of additional features that have been overshadowed by the announcement of the focusing system and Dual Pixel RAW. And sure, I get it, focusing is more important – but the little features are what made me fall in love with the camera. What are those features, let us just go down a list —
1. The focus-feature button
It allows you to switch focusing types quickly (from single point to cross point, etc, etc.).
2. Hybrid-ish Viewfinder
The viewfinder allows you to add various pieces of information, from things as useless as battery power, to as useful as an electronic level built into the viewfinder.
3. An Actual Useful Touch Screen
The touchscreen allows for a bunch of new controls, allowing you to focus, select images, zoom, and more. Up until now, Canon’s touchscreens on DSLRs have been pretty functionless by most people’s standards. 4. Quieter operation If you’re coming from the Mark III, you’ll find the 5D Mark IV to be quite a bit more quiet, with it’s new(er) mirror box design
However, there are some downfalls with the system as well. Most notably, is the lack of CFast card slot on the system – extending the life of the Compact Flash slot for another generation. Don’t get me wrong, I don’t want to switch to new memory cards either, but CFast is exceptionally better than Compact Flash at its current state. While Compact Flash is (currently) limited to around 100MB/sec (averaged), CFast achieves speeds five times as fast. While that may not be important to a camera that shoots 7fps, it can be a huge advantage to those who need to upload images to their computers quickly…and can really speed up the workflow for those in fast pace environments.
I took a support call a couple of weeks ago that came to mind a few times while I was testing the 5D Mark IV. A relatively inexperienced customer (late high school or early college if I had to guess) called in for help putting together a 5D Mark III package. He was shooting a short film and needed a viewfinder, a top handle, and an XLR adapter. After getting the 5D Mark III in his cart, I recommended a Zacuto Z-Finder, a Wooden Quick Kit (just the top section), and Beachtek DXA-SLR Pro. He was ready to place the order before I interjected. “You know, you’ve created a Canon C100 here. If you’re willing to switch cameras, you’ll have a simpler setup, dual pixel autofocus, better battery life, and two card slots. Plus, it’ll be cheaper.” He’d never considered a dedicated video camera because his teachers had all told him that the only affordable way to shoot high-quality video with a cinematic look on a budget was to use a DSLR. Seven years ago, they would’ve been right. The 5D Mark II revolutionized the video market in ways that are still being felt today. Whole companies (including Lensrentals) sprang up to support amateur filmmakers who, all of a sudden, had a way to capture video with shallow depth of field and high dynamic range without pawning all their worldly possessions.
Now, though, we have a few more options. You no longer have to cobble together a Frankenstein’s monster of third-party accessories just to make a DSLR usable. Cameras like the Canon C100, Sony PXW-FS5, and Panasonic AF100, will give you video at least as good as what you can get from a DSLR (better in most cases), plus XLR inputs, physical audio controls, viewfinders, unlimited clip length, etc. In short, they’re designed with video in mind from the outset, rather than it being a feature tacked-on to a camera intended for stills. As a videographer, this leaves me wondering where exactly the 5D Mark IV fits in my workflow. Given the specs, under what circumstances would I reach for this particular camera over the myriad other options available?
About those specs: first of all, yes, you can shoot 4K (8-bit 4:2:2) with the 5D Mark IV. However, you’re limited to 30p or below. 1080 will give you up to 60p, and, frustratingly, 120p is limited to 720 resolution. Also frustrating is the total lack of 4K output over HDMI. 4K recording is limited to a 1.74 crop which, in addition to making reframing necessary when switching from stills to 4K video, introduces some very noticeable rolling shutter issues. Without scientific testing, I’d say the rolling shutter is nearly as bad as it is on the A7S, which is the camera I use in the office when I’m demonstrating what a bad rolling shutter looks like. The 5D IV also lacks some major features I’d expect out of any modern video camera: No peaking, no zebras, no focus magnification while recording, and no log profile. Hopefully, some of this can be fixed through firmware updates or by the good people at Magic Lantern, but your $3,500 camera shouldn’t have to be improved by volunteers accepting bitcoin donations. Finally, regarding usability, the menu structure just isn’t designed for video. As always, audio controls are too hidden, but there are smaller annoyances that snuck up on me. For instance, you initiate 120p recording by selecting an “Enable” button in the “Recording Settings” menu. You end high-speed recording by navigating to the same menu and selecting “Disable.” After disabling 120p, does the 5D return you to the recording setting you were using, say 4K 24p? Nope. It goes back to the default (1080, 60i) every time, necessitating another dive into the menu structure to change back to your chosen settings. This had me cursing under my breath multiple times while surrounded by children and Knights of Columbus at a fair.
There are things to like here, though or at least a thing. The autofocus performance, as in the C300 Mark II, is awesome, and I mean that in a literal sense. It inspires awe. The touch screen, rather than being the useless gimmick I was expecting, became my tool of choice for controlling focus. Accurate face tracking allowed me to just point at the person or thing (it seemed to work just as well on dachshund faces) I wanted to keep in focus, and then just re-frame as needed. It almost never hunted or lost track of subjects. The only downside I could find is that it doesn’t work during high-speed recording.
So, back to the initial question, under what circumstances would I choose this camera over everything else in the Lensrentals inventory? To answer that, I have to first admit that a lot of my criticism above is unfair. I can’t very well complain about a lack of good video features because this isn’t a video camera. Both the millions of other amateur filmmakers and I brought up on the 5D Mark II need to remember that. Video cameras have things like XLR inputs, internal ND filters, and menu structures designed for video work. What it is is a still photography camera and a fantastic one at that. I do almost all of my still photography on a 5D Mark III, and that’s where the 5D Mark IV will fit for me. If something comes up while I’m shooting stills that I think I’d like to take a quick video clip of, then I’ll be happy I can do it in 4K. If video functionality is a priority in any way, I will go with a camera designed for video, and I’d recommend you do the same.
Below is some sample footage I shot with the Mark IV this weekend. Since C-Log is, unfortunately, absent, I shot everything with Technicolor’s Cinestyle Profile, which is available for free here. Everything was left ungraded, including stuff I exposed imperfectly. Unless otherwise noted, the day footage was shot at 400 ISO, and the night footage was shot at 800 ISO. If you have any questions, feel free to let me know in the comments.
If you haven’t looked at it yet, look at Roger’s teardown of the Canon 5d Mark IV system. As shown by him, the weather sealing has been improved, and subtle changes have made the Canon 5D Mark IV and upgrade from the previous models. When holding, the system feels very similar to the Mark III, giving you a robust build in a comfortable form factor.
Heads up, here comes a short rant. Upon the announcement of this camera, it was instantly met with some harsh critics on the feature list of the system. People want a camera that can shoot medium format quality images, with the speed of a Canon 1DX Mark II, and the video functionalities of a RED Weapon – and they want the price to sit under $3,000. Sure, this camera doesn’t have anything and may not have pushed the bounds of the industry, but the Canon 5D series has never been about being revolutionary in features, but being revolutionary in practicality. The 5D Mark II came with video functionality, which set it apart from the competition – but it wasn’t perfect. You were limited to manual focus, and here even further limited to framerates and resolution. The Mark III introduced an useable focusing system (I kid, I kid), but improved on everything the Mark II had to offer, without overreaching with unusual or groundbreaking features. The Mark IV has taken every feature of the Mark III and improved it a little bit. It may not be completely cutting-edge, but they made an incredibly loved and capable camera even better on every single metric. People need to stop expecting the industry to evolve faster than it can. It’s already moving fast, and the Canon 5D Mark IV keeps pace with every single competitor in the DSLR field. It’s feature-full and practical – maybe not as revolutionary as the Sony a7 was to the mirrorless world, but it will certainly be the most used camera in the industry within a years time.
What We Liked –
Dual Pixel RAW Looks to be an Incredible Feature
Lighting Fast Autofocusing for both Photo and Video
Wifi and GPS work great and have a lot of functionality
Image quality is great, and the additional resolution is a nice touch
What Could Be Improved –
It’s still a photo camera with video functionality
4K is cropped to a 1.7x sensor
Still missing key features found on 3rd parties (in body stabilization for one)
No CFast slot (Compact Flash & SD Slots Only)
So is the Canon 5D Mark IV a worthy upgrade? Yes….yes it is. Canon managed to combine what we loved about the Canon 5d Mark III, and improved on it in every metric. The autofocus is better, the camera is faster, the video functionality has improved, the lowlight has been improved, and there are plenty of additional features to set it apart. The Canon 5d Mark IV is an exceptional camera and fixes a lot of practical issues I’ve had with previous models.
I’ve mentioned in some other posts that our optical tools can do a lot more than just test a lens’ MTF. For most of the last two years, though, testing MTF is what we’ve been doing. We may not seem all that busy, but we’ve assembled what is probably the world’s largest database of current camera lenses; approximately 1,500,000 measurements on 1750 copies of 330 different lenses from 15 manufacturers.
Recently, though, we’ve started exploring some of the other testing available to us. Partly that’s because we’re geeks and like doing this stuff, and partly because we’re looking for more and better ways to test lenses. One of the things we’ve been doing a lot lately is looking at field-of-focus curves. There is a LOT of information in field-of-focus MTF testing, enough that makes it worth doing them even though each takes a lot longer than a standard MTF test.
This is an introductory article – one where we’re showing you what we’re finding out as we’re finding it out. If you already understand all about field vs focus graphs you won’t get much here. But if you don’t, this should be a nice, painless introduction to some of the new testing we’re doing.
So What Are Those Amazingly Gorgeous Graphs, Anyway?
Officially, they’re called an MTF vs Field vs Focus graph and gorgeous part comes from software written by uber interns Markus and Brandon. They’re fairly intuitive, but also have a lot more information in them than you might realize so let’s talk about what they are and how they are made.
Let’s start with a regular MTF graph. Many of you have seen them. Many of you don’t really understand them, but that’s OK. The MTF vs Field vs Focus graph are actually simpler in many ways and you don’t really need to speak MTF to appreciate them. So read along for a second.
Notice the regular MTF graph above goes from 0mm of image height to 20mm along the horizontal axis. Image height isn’t a good word for us photographers. It really should read ‘distance from center toward the side of the sensor’. The center is “0”, one edge is “20”.
The raw data the optical bench gives us actually goes from -20mm to +20mm, that is from one side of the sensor to the other, like the graph below. To make that graph above, we actually average all the measurements from both sides of center and and plot them as though it was showing one side (from center to edge). The actual information that comes from the optical bench puts the center in the middle and shows both sides, like this.
So, the takeaway here is “Field” is from one side of the camera sensor to the other. The field is also called ‘Image Height’ by Geeks who measure stuff in labs, so in the graphs ‘field’ or ‘image height’ both mean distance away from the center of the image.
When we make an MTF curve like those above, we set the lens to infinity focus and lock the focus ring in that position. (Locked is a technical term meaning ‘stuck some gaffer tape on the focus ring’.) The Optical bench then fine-tunes focus, determining the exact focus position at which the MTF is highest at the center of the lens. It’s very accurate, measuring focus in 5 micron increments. (In case you don’t know, the infinity mark on a photo lens means ‘around infinity’. On a Cinema lens it should be accurate, but still might not be 5 microns of focus accurate.) Once the optical bench has determined the best focus, it measures the MTF from one side of the lens to the other, remaining at that ‘best for the center of the lens’ focus position.
In photographic terms, if you used center-point autofocus on a fence at right angles to you, the MTF curve would show you how sharp that fence would be from one side of the image to the other. People might look at that photograph, though, and say “Halfway from center, the grass in front of the fence is in better focus than the fence, and at the edges the grass behind the fence is in better focus.” That’s commonly called field curvature, but probably better described as plane-of-focus curvature.
Another related comment is “If I used the left sided autofocus point, wouldn’t the MTF (OK, they’d say sharpness, but I’m being all technical here) be better for that part of the fence? The answer is probably yes. But if you do that, probably the center would not be as sharp. Because the best focus at that part of the fence may well not be the best focus for the center of the fence.
When we do a Field vs Focus the optical bench is set differently. At each point, it measures and records the MTF over-and-over as the focus is slowly changed through an 600 micron range. (These graphs are labeled from 0.6 to -0.6, which is incorrect, it should be 0.3, but I’m not going to remake all the graphs since it’s not really important for this article.) At each focus point the MTF is recorded. So the vertical axis of the graph of MTF vs focus position. The 0,0 point in the center of the graph is best center focus. As you go from left to right across the image, you can see that the best focus can be in front of, or behind, where the best focus point at the center of the image.
This is why MTF vs. Field vs. Focus is in many ways a better test than just MTF. For every point across the image, it shows you where the best focus is located and what the best possible MTF is at that location.
We’re measuring our curves at f/5.6 so the focus range is rather thick. This is mostly because it smooths out the graphs and shows the shape of the field well. Wide open, many lenses get so soft off axis that it’s harder to see the shape of the field. And f/5.6 gives us a ‘common aperture’ that all lenses can reach so the graphs will be similar.
The MTF Part
In these graphs, MTF is represented as a color, with red as the highest (sharpest) and blue as the lowest. There’s a key on the right side and some outlines around each area on the graph showing you the MTF to the nearest 0.1. So you know the red area in the graph above is an MTF of > 0.8 for example, orange is 0.7 to 0.8, etc.
We lose some MTF information, though, compared to a standard MTF graph. It’s a fair trade for the new information we get, but still there is some loss. One thing you may have noticed in the graph above, the curves are done at 30 lp/mm. The standard MTF graph shows us MTF at multiple frequencies, but for this graph we have to chose one of those. The curves are very, very similar at all frequencies, though, so this isn’t too much of a loss.
One other thing some of you probably noticed; the graph above was for just the sagittal component of the MTF. We can’t plot both the sagittal and tangential curves on this graph like we can a regular MTF graph. (If you don’t understand sagittal, tangential, and astigmatism very well, I recommend this excellent article by Paul van Walree). So we have to make two graphs for each lens; one sagittal and one tangential.
The example above is for an individual copy of the Canon 35mm f/1.4 Mk II lens and it shows a couple of important things. First, the curvature of the sagittal and tangential planes are different: the sagittal plane has a wide M-shaped curve, while the tangential is (overall) rather flat. So there is some astigmatism in this lens, although not much. Second, the tangential curve isn’t quite symmetrical, it’s a little different on the left than the right. This is a copy variation effect. This copy is a bit decentered, although not enough that you can tell it on anything other than an optical bench.
So How is This Useful?
Actually, I’m going to take up several blog posts talking about we might use these. But lets start with one: knowing a lens’ field of focus curve can be helpful when ‘choosing’ or ‘using’. Let’s say I’m considering buying a 50mm wide-aperture prime lens. Or let’s say I already have one and want to get the very most out of it.
Knowing what the field of focus looks like can help me choose the best 50mm for the kind of photography we do. If I already have one, it can help us frame a shot for the strength of my lens. Not many of you have considered it, because you don’t have a handy reference for field-of-focus curves. (Some of the best photographers figure it out when they add a new lens to their bag, though.)
One important thing to note: When our field of focus curve is moving towards the top of the graph, the focus curve of your image is moving towards the camera. Think of the camera as sitting a couple of inches above the graph and focused down toward the center of the graph. The field of best focus in the graph would then look like the field of focus would from the camera. I’ll give you an example later.
Let’s look at the field curvatures for some 50mm lenses. I’ll make a few comments as we go and then some overall comments after.
One thing that should be apparent is the tangential field for this lens is generally not as sharp as the sagittal field, even stopped down to f/5.6. Another is that the fields are entirely different shapes (they are for most lenses). It should be intuitive that out near the edges this lens will be astigmatic. Well, maybe not at f/16, but did you actually buy a wide-aperture prime to shoot at f/16? The field curve is a good demonstration of why the MTF curve has marked astigmatism at the edges.
The inexpensive 50mm Canon has a more extreme sagittal “M” than the f/1.2 lens did, but the tangential field is quite flat. We would expect this lens to have some astigmatism in the 10mm to 15mm off axis area (the middle third of the image) even stopped down, but that it would have less astigmatism near the edge. Also you can see that the tangential and sagittal fields are more evenly sharp in this lens.
And I guess this is a good example of why you don’t spend an extra thousand dollars for f/1.2 if you plan to shoot at f/5.6.
The Sigma has a very slight M curve in the sagittal field, and a fair U curve in the tangential field. The designer has actually used this effect to cross the astigmatisms back-and-forth so there’s never a lot of astigmatism, as you can see on the standard MTF curve.
Also notice how the sharpness (at f/5.6 remember) stays good out to the very edge of the image. One point that is apparent here, and useful to know if you’re shooting landscapes and architecture: in the middle third of the image (from about 10mm to 15mm from the center of the sensor) both fields are curving in the same direction. So a two dimensional subject, like the fence I talked about above, or the test chart you’re shooting in the basement is going to focus in a slightly different plane than the center.
When the Sony Planar T 50mm f/1.4 ZA was first released, people commented that it had a different look than other 50mm lenses they were shooting with. The field curvature shows part of the reason why (and also why this is not just a Zeiss remake). The sagittal plane of the Sony is extremely flat; the most supine of any 50mm lens. The tangential plane has a different curve than the others (and like the Canon 50mm f/1.2 is not quite as sharp as the sagittal plane). This is part of the different ‘look’ of the lens. It also tends to make the field of focus flatter than the other 50mm lenses.
The Zeiss Makro Planar f/2 has a more accentuated curve, with pronounced sagittal “M” and tangential “U” curves. You’ll see in subsequent posts that this sort of a Zeiss look; a lot of their primes have similar curves. Actually if you overlay the two curves in your mind, you realize that out to 15mm (3/4 of the way from center to edge), the curves are almost identical, meaning there’s very little asigmatism until you get in the outer 1/4 of the image.
For those who can’t overlay the curves in their mind, I’ll do it for you. Here’s a simple image where I put the two field curves over each other, then used the Photoshop difference filter. That dark area in the center is where there is virtually no astigmatism.
On the other hand, the curve of that dark area shows how the field of focus curves in your shot, too. Remember, though, this is the field of focus at infinity. This is a Makro lens so it has a much flatter field at close distances. Non-macro lenses usually don’t change their field of focus all that much at closer range.
The Otus is a unique lens and I think the field of focus curves show another way that it’s special that the standard MTF chart doesn’t show. Although not exactly the same, it should be readily apparent that the sagittal and tangential fields for this lens have very similar curves. It’s the only 50mm we’ve seen that is this way, although the Sony and Sigma lenses were to some degree.
You will probably notice the very slight tilt in the copy of the Nikkor 50mm. Please ignore it, it’s not significant for today’s discussion. This lens has a fairly typical sagittal plane curve, similar to the Canon or Zeiss 50mm lenses, and a tangential field that has a bit of a U curve. You should be recognizing this pattern as fairly typical for 50mm lenses. That isn’t surprising since almost all of 50mm lenses have a double-gauss core design; we’d expect most of them to be somewhat similar.
So Why Do We Care?
Well, for several reasons, I think, only some of which are apparent from this introductory post. I’ll be doing several posts about this over the next week showing you some other things we’re using field curvatures to look at.
Knowing the field vs focus curve of a lens can sometimes help you as you frame a shot, or even choose a focus point. You can certainly see how using an outer focus point for several of these lenses will put the center off focus, or how if you focus-recompose you may get some unexpected change in focus. Having an idea of how the field of focus of your lens is shaped can be quite useful.
Let’s do that example I promised earlier. Here’s a repeat of the summary graph I made of the two fields for the Milvus 50mm f/2 lens.
In theory, for a shot at distance we would expect the field of best focus to curve towards the photographer a bit as you go from center towards the edge, then get kind of astigmatic and softer at the very edge. Our lab graph, because it’s magnified, is going to curve more than a photograph would, but the pattern should be similar. So I took a Milvus out to a hill behind our office and lined up shots from a position nearly parallel to the slope.
Then I took f/2 shots at a couple of different focused distances on the slope (the tall grass was almost at infinity focus), and ran Photoshop’s find edges filter to find the areas of sharpest focus (grass is nice for this because it becomes just a dark area when you downsize the image).
Focused a few feet back
Focused on the tall grass at the top of the hill.
The curvature of the field of focus seems pretty obvious and agrees with what I expected from the lab results. Depending on what you’re going to shoot, knowing this might be useful when choosing a lens. (You can quickly correct for distortion in post processing, but it’s harder to correct for out-of-focus areas.)
Oh, and remember I mentioned that the 50mm Makro has less field curvature when close, and almost none at macro distances? Here’s the same treatment on a shot of some mulch at about 2 meters distance. There are some other variables here, but I think the field looks flatter, although not as flat as it would at true macro range.
If you’re in the market for a 50mm lens and want to shoot a lot of architecture, than a curved field like the Zeiss 50mm Makro might not be your best choice (yes, I know it wouldn’t be your best option for lots of reasons other than this). It should also be pretty obvious, though, that you can take your lenses out and do just what I did above to get a good idea of what the field of focus curve looks like for any of the. All you really need is a grassy field, or a mulch bed, and Photoshop.
That might not give you as clear a picture of astigmatism as the lab graphs do, though. Astigmatism has quite an effect on bokeh, so knowing where areas of inevitable astigmatism are might help you frame or crop your shots.
Of course, you might not care a bit. Our next post will simply be putting up the field curvatures for a number of prime lenses of different focal lengths, giving you a resource for that. If people find them useful, we’ll start posting more of them. If nobody cares, we’ll just make framed prints of them to decorate the office.
There are other interesting things we are trying to do with field curvature, though, and I’ll get to those in later posts. First among these is adding field curvature to our screening tests. The curves I showed you today are hand picked to be nice and fairly level. In a later post I’ll show you how sample variation causes tilts of the field. It’s an interesting explanation for what many people call decentering. Once you see it, you’ll be able to test for it at home, BTW. But be patient for a bit. Doing this stuff takes time.
Roger Cicala, Aaron Closz, Markus Rothaker, and Brandon Dube