Long ago in a lifetime far away, I discovered photography. I loved it. I mean, I really, really loved it. Not just learning how to make photographs. I loved learning how the camera and lenses made those photographs. I loved learning about the major and minor differences various lenses had. I spent every free moment using equipment and learning about our craft. I spent almost every free dollar buying more equipment.

In a burst of insanity I decided the best thing a gearhead photographer like me could do was to start a photography rental company. I’d have to buy everything because now it would be ‘stock’ and ‘assets’. Brilliant!! Like people say, it’s not work when you’re doing what you love. (I will mention, for those considering a similar path, that when you are working 14 hours weekdays, 8 hours Saturday and Sunday, and losing money, you should not mention how much fun it is to your wife.)

Lensrentals was more successful than I’d ever dreamed it could be.  What I found out, though, was that I wasn’t running my personal photography toy store.  I was leasing office space, negotiating shipping rates, filling out two gazillion governmental forms, learning how to regain stolen equipment, obtaining lines of credit, hiring people, managing employee benefits, trying to figure out what would rent well, and various other things that did not fit my definition of really fun stuff. Not to mention trying to learn about those business –type things like return-on-investment, depreciation, profitability, market share, corporate tax structure, and a bunch of other terms I still can’t understand.  (Maybe unwilling to understand is more accurate, but whatever.)

The bigger the business got, the less time I spent with the equipment I loved and the more time I spent being a businessman. I learned several things in a fairly short time: 1) I’m not a good businessman, 2) I don’t want to become a good businessman, and 3) I want to play with the toys and lots of business responsibility keeps you from playing with the toys. For those of you thinking I should add “I refuse to grow up” to that list, I had figured that out way before Lensrentals started.

During the last several years Drew, Tyler, and Kristin, who actually have business sense and training, have taken over the day-to-day operation of Lensrentals. They not only do it a lot better than I did, they like doing all that stuff I hate to do. Even stranger, they’ve never expressed the slightest interest in taking lenses apart. Go figure. They all came here when the company was still small, leaving secure corporate jobs and taking significant risks (and pay cuts) to do so. They’ve had as much to do with the growth and success of Lensrentals as I have.

So it makes sense, and is with real enthusiasm, that I’ve accepted an offer from the current management team to buy a majority interest in Lensrentals. I will remain owner of a significant portion of the company’s stock, but am now “one of the owners” not “the owner”.  I’m totally comfortable that the company I started will continue to be run the way I wanted it run, because the people buying it are the ones who’ve been running it that way for several years.

The best part is they basically told me “you can do whatever you want to do as long as you remain an active part of Lensrentals.” So going forward, I will continue to head our quality assurance, repair, and research efforts. In other words I will spend my days taking stuff apart, figuring out how it works, testing it, repairing it, and writing about it. I’m in gearhead heaven once again.

What will you notice that’s different? Nothing. The only thing changing is that I’ll have more time to do the stuff that leads to most of these blog posts.

Roger Cicala

Lensrentals.com

Every once in a while, though, I’ll evaluate a piece of equipment as a possible rental item and really be impressed with it. Impressed enough to write something about it even though we don’t even stock it for rent (yet). That happened today. We received a Nanoha Ultra Macro lens for mirrorless cameras that I’d ordered to evaluate as a possible rental item. Let me start by saying my expectations were low. The lens is made from a microscope objective so it has a maximum f/11 aperture. It has some LED lights on the front which I usually think of as something cheap and ineffective. If you Google Nanoha you get 42 pages about a female Anime character. But they had some nice images on their site, and I thought it might, might be worth a look.

I was a bit more impressed when I opened it up: the LED lights are powered by a small self-contained unit with two AA batteries, and the LEDs were really pretty bright. Everything was well built and the instructions were clear. The focusing and aperture rings were smooth and solid. It comes with 5 little holders to put stuff in at just the right distance in front of the lens to focus on it (shooting range is a rather close 8 to 11 millimiters), which I thought was a nice touch.

Nanoha 5X mounted to an NEX 7

You can shoot without the holders (which we did). A nice tripod with a focusing rail is not a must, but it’s near to a must. So it’s a really limited, one-trick pony lens that shoots things at 4x to 5x Macro. Like, say, the Canon MP-E 65 5x Macro lens. Not something most people would use everyday, but really just an absolute blast to play with. How much of a blast? Enough that the entire inspection department got yelled at and told to get back to work after I led them on a scavenger hunt for more little stuff we could take pictures of. All work ceased for an hour while 7 of us were fighting over who got to play with it next.

Since we had such a good time with it, I thought I’d share some of the images Tim made with it. I’ll post a Nanaho Macro shot, followed by a standard shot of the same object. See if you know what the Macro showed before looking at the item in a standard image.

Ribbon cable with chips and fuses

Microfiber lens cloth

Piece of packing foam

Toothbrush

leaf

And a few more images that I didn’t have regular shots of. In two of the three cases because we ate or drank the photographic subject before we could do regular shots. In the third case, well, he (or she) escaped.

First, some freshly ground coffee.

Ground coffee (Brazillian Monte Carmelo for those who are into it as much as we are).

A piece of bread (whole wheat, I believe)

And what would a Macro post be without the obligatory spider? I mean it’s the macro lens equivalent of the pet dog shot we all take with a new portrait lens, right?

Obviously we like this little lens. There was a fight over who got to take it home tonight, and there’s another brewing over who gets it for the weekend. We’ve ordered a couple of copies for rental items, but if you’re a m4/3 or NEX shooter who’s into this kind of thing I’d buy one. At $480 it’s reasonably priced, especially when you consider it comes with a built in light.

Remember, though, the working distance is 8 to 11 MILLIMITERS. You’ll either want to take pictures of things  you can put in the little plastic holder, or you’ll want some macro photography aids like a focusing rail and things to hold your subjects in position. But if you’ve always thought “I wish there was a microcsope type macro lens for 4/3 or NEX format, well, now there is.

Roger Cicala

Lensrentals

May 2012

Making the project something we could do in reasonable time means cutting some corners. First we can’t test every camera. We chose the Olympus OM-D EM-5 for several reasons. We wanted a camera with 16-megapixel resolution, which eliminated most m4/3 cameras. Also, the physical layout of the Olympus lets us test more quickly in our lab than we can with any of the 16-mPix Panasonic cameras. There just wasn’t enough time in one day (all we could set aside for this right now) to do two different cameras.

Second, we split the test into two sets of lenses because there were so many to test. In this part we did lenses that were 25mm or wider in focal length. We’ll do the longer lenses later. Zooms with a long range were tested near their wide end in this test, and will be tested again at longer focal lengths when we do the longer lenses.

Disclaimer

The usual “don’t read this stuff and go insane” cautions apply: this is a test of lens and sensor resolution for MTF 50 (detail resolution) done at a distance of 10 to 30 feet, depending on focal length. The results might be different at 4 feet or 400 feet. The results might be difference if we tested at MTF 10 for best acutance. Focus is done manually and bracketed so it’s not a test of a camera’s autofocus ability. The tests use a controlled-lighting test-target with a hardware mounted camera at ISO 400, so photos taken in the dark of night or hand-held for 12 second exposures will give slightly different results. It doesn’t measure autofocus speed, lens size, manual focus feel, bokeh, color rendition or anything like that. It’s not a lens review; it’s one simple test of resolution.

More importantly, remember that while we are testing RAW files, both Olympus and Panasonic seem to do some in-camera corrections on their own lenses, but not the other brands. We don’t know what effects, if any, that might have on this test. Possibly Panasonic lenses might do a little better on Panasonic cameras and Olympus lenses a little worse. We’ll figure that out later, but I doubt any such corrections will affect the MTF 50 at all. If it did the effects should be minor and limited to the edges and corners. But we don’t know for sure. Yet.

Addendum 4/13/12: I had hoped that the m4/3 community might not be quite as Fanboy riddled as Canon and Nikon. Obviously I was wrong about that. Because there was such an uproar about the results of the Panasonic / Leica 25mm I’ve repeated the tests on 6 copies (all that we have) and also on Panasonic cameras, because because Fanboys have been on suicide watch and full attack mode since they’ve taken them so out-of-context. The average of 6 lenses on both Olympus and Panasonic 16 Mpix cameras are now reported. They are basically unchanged.

The Lenses

We had a nice selection of wide-angle m4/3 lenses in stock on the day we conducted these tests:

• Voigtlander 17.5mm 0.95 Nokton and 25mm f/0.95 Nokton
• The Pancake lenses: the Panasonic 14mm f/2.5, Olympus 17mm f/2.8, and Panasonic 20mm f/1.7
• Other primes: the Olympus 12mm f/2.0 and Panasonic/Leica 25mm f/1.4 ASPH
• And a few zooms: the Panasonic 7-14 f/4, Olympus 9-18 f/4-5.6, Olympus 14-42 f/3.5-4.6 II R, and the Olympus 12-50 f/3.5-6.3 EZ

Imatest Results

The values are for MTF-50 (which correlates with fine detail resolution) measured in line pairs / image height. The first (higher) number is the MTF 50 measured at the center of the lens only. The second (lower) number is the average of the MTF-50 measured at 13 points including the center, 4 corners, 4 sides, and 4 mid points. I keep a point total for every time someone posts the question “what do the two numbers mean” as an indicator of the reading comprehension for each group of camera users. I have high expectations for m4/3 users, so please don’t let me down.

I’ll also mention that numbers sometimes make minor differences seem really large. A difference less than 50 lp/ih is probably not noticeable in real-world photography. So if you print a reasonably sized image from a lens resolving 860/750 lp/ih and compared it to a shot with another resolving 810/700 lp/ih the difference would probably not be noticeable. You would almost certainly notice a difference of 100 lp/ih.

At Widest Aperture

The first graph shows the numbers for each of our lenses (zooms measured at 30mm) with the lens aperture wide open. This test isn’t a level playing field, since some lenses are f/4 wide open while the primes are at anything from f/1.4 to f/3.5. But since some people tend to shoot every lens wide open, it may be useful to know how well (or not) the lenses do at their widest aperture. I’ve listed them from widest to longest focal length. The zooms were all shot at 14mm so they might be a bit better or worse at other focal lengths.

MTF 50 at Widest Aperture

*Panasonic-Leica results on this test are the average of 6 copies. The average numbers are slightly better at f/1.4 than  the first version of this article, which reported only one copy, but the difference is not really significant.

There’s not a lot to see from this set of numbers. As usual, good primes are as sharp, or sharper, at wide apertures than consumer-grade zooms are at lower apertures. The Panasonic pancake lenses pleasantly surprised me. Pancakes are usually not the greatest lenses, but he Panasonic 14mm and 20mm are really quite good.

Stopped Down to f/2.8 or Smaller

We can level the playing field a little bit by shooting the wide primes at f/2.8, as shown in the graph below. It’s somewhat more meaningful: the zooms are still at smaller apertures, but everything else is shot at f/2.8 here.

MTF 50 at f/2.8

*Panasonic-Leica results on this test are the average of 6 copies. The average numbers at f/2.8 are slightly better than  the first version of this article, which reported only one copy, but the difference is not really significant.

By f/2.8 the superiority of most of the primes over most of the zooms becomes pretty apparent. The Olympus 17mm f/2.8 is easily the weakest of the prime lenses, which isn’t really surprising. It’s an older design and a consumer-grade pancake lens. The two Panasonic pancakes being so good surprised me, though. They’re not much more expensive than the Olympus 17mm. I had expected a bit more out of the Panasonic Leica 25mm given it’s cost and build quality. It has other good qualities, this is simply the results for MTF 50. The Voigtlander lenses, despite being built for ultra-wide aperture (which usually results in a rather soft lens) did quite well. But as easily the most expensive lenses in the group, that seems appropriate.

Personally my biggest disappointment was in the Panasonic 7-14 f/4 zoom, which is probably my favorite m4/3 lens. But we were testing at 14mm, and that lens is actually a bit better at the wide end. And really, it’s probably a bit much to ask a lens to be this incredibly wide, and also incredibly sharp. The Nikon 14-24 pulls it off for about $2,000, but that’s the only one I can think of.

MTF 50 at f/4

We can level things out even further by shooting all of the lenses at f/4. Most of these lenses would get a bit sharper still at f/5.6, especially in the average (as opposed to center) resolution.

MTF 50 at f/4

*Panasonic-Leica results on this test are the average of 6 copies. The average numbers at f/4 are slightly lower than  the first version of this article, which reported only one copy, but the difference is not really significant.

There’s really not much new information here that we didn’t already see at f/2.8. The Olympus 9-18 and 12-50 zooms are clearly better than the little 14-42 zoom. The Panasonic 7-14, despite working at such wide angles, is better than either of the others. Overall another “you get what you pay for” situation – slapping  II on the name doesn’t make it a great lens. (BTW – although I expect m4/3 shooters to go a little less Fanboy than the Canon and Nikon guys, let’s get this out of the way: some Fanboy always says “the rental guy wants you to rent the most expensive lens”.  Actually the rental guy could care less: the profit margin is the same on a really expensive lens and a cheap one.)

Of the prime lenses, only the Oly 17 pancake isn’t very good; the Panasonic pancakes were clearly better. The Panasonic/Leica 25mm disappointed a bit: it was good but I had expected it to be THE best of the bunch and it’s not. I only had one copy the day of this test, though, so I would take this result with a grain of salt until I can repeat it with other copies. There’s a chance it was just a copy variation thing.  The Olympus 12mm was just excellent, though, and the Voigtlanders provide an amazing wide aperture lens.

Part 1 Summary

Compared to the NEX system lenses I just tested, m4/3 users have a host of wide-angle, native-mount choices. There are good pancakes, standard primes, interesting (and expensive) ultra-wide aperture primes, all at reasonable prices. There’s a good f/4 ultrawide zoom and a couple of reasonably sharp zoom lenses. The big hole, as I see it, is that there’s no wide-aperture zoom, period. For my shooting style, the m4/3 begs for a wide aperture.

Remember, we’re just talking about resolution here. When I’m choosing a lens, it’s my starting point: I require good resolution. But that’s all it is, a starting point. If you’re seriously considering some of these lenses, go to a good review site where you can get more in-depth information about distortion, handling, focusing accuracy, etc.

In this part we’ve looked at most, but not all, of the m4/3 lens choices for shooting at 25mm or wider. We’ve only tested on the Olympus OM-D. We’ll do some testing on at least one of the Panasonic 16mm cameras just to make certain there’s no significant difference soon (I doubt there will be, but it’s possible). We’ll also do a second post on the longer lenses in the next couple of weeks.

Roger Cicala

Lensrentals.com

May 2012

As always, it is our goal to be the best rental company in the business. As part of that, we want to have the easiest to use and all-around best website of any rental company. So, over the past two years since our last iteration of our site went live, we’ve gathered feedback from all of our customers about what they liked and what they didn’t like about our site. For the past six months, we’ve put a lot of work in redesigning our site from the ground up, to fix the things that people don’t like, and to make the well received features of our site even better.

Navigation

We’ve gotten a lot of feedback that the top-button navigation system on the old version of the site was confusing or difficult to navigate. We’ve moved the navigation from the top to the left side of the screen. To navigate, simply select your camera system, and then proceed through the categories as you did on our old site.

At any point, should you want to choose a different camera system to navigate to, simply click the name of the current camera system to be presented with the list of all camera systems.

Filtering & Sorting

Another common point of feedback we’ve received is that, because we now carry so many products, it can be difficult to narrow down your selection to just a few products. To improve upon this, we’ve added filtering options. Our filters will work whether you’ve accessed a list of products through our regular navigation, or if you’ve used the search function of our site.

At this time, the filtering categories are mostly lens-specific such as focal length, maximum aperture, and active stabilization. We hope to expand the filtering choices to other product options in the future.

We’ve also added the ability to sort a list of products by different attributes such as weekly price, popularity, newness, or focal length.

Product Pages

We know how much everyone loves the large amount of information we try and give you on each product, whether it is Roger’s Take, MTF charts, or detailed specifications. We also know how much everyone hates how long and disorganized all this information has made some of our pages. That’s why we’ve added tabs to our pages, allowing you easy access to all the information available, if you need it, without cluttering up the page if you don’t.

Shipping

Along with the new site, we’ve changed our default shipping carrier to FedEx, as well as changed our shipping speeds on some orders. Rest assured, whether our site tells you your order is going to ship via Next Day Air, 2nd Day Air, 3rd Day Select or Ground, your order is guaranteed to arrive on the date you selected, just like before.

Since we know some of you prefer UPS, UPS shipping will always be available, for a slight extra charge (it costs us a bit more to ship UPS, so we have to charge a bit more). Simply change your shipping method using the drop-down menu during checkout.

As always, we have support available via phone, email and chat during business hours (8:00 AM – 5:00 PM CT), and email support available after-hours and on the weekend if you run into any problems with our new site, or simply can’t find what you are looking for. Contact us at any time!

Let me say it here first: I knew this was going to be the fix since the first time I took one apart: Canon has this very cool black tape they used to cover circuit boards (I’m assuming either water resistance or electrical shielding or both) and I figured they’d just slap another piece over (or under, depending on your point of view) the top LCD light. Which is exactly what they did. Yes, I’m making fun, but it’s a perfectly good solution and it works flawlessly.

And because I know you have enquiring minds: I did power the camera up with the shell off in a dark room. There is no more leak.

Addendum: for those who notice there is a black plastic piece over the shutter button that was removed in the first photo, but not this one.

Read This Please!!!

Sometimes I forget that other people don’t spend most of their days looking in cameras and lenses. Some people seem to think tape is bad or cheap fix. It’s not. Actually, I can’t think of any SLR camera that doesn’t have a bunch of tape inside. Nor can I remember any high quality zoom lens that doesn’t have tape inside (some of the cheaper consumer grade lenses don’t). This stuff lasts for the life of the camera and then some. Trust me, I’ve taken some water soaked equipment apart where the only thing still working was the tape.

In a previous post, I praised the broad sheets of the same tape used to cover all of the circuit boards: it obviously provides added protection. This solution seems silly, but it’s logical and effective.

Roger Cicala

But some of us (myself included) like to shoot native-mount lenses, or can’t afford the price of Leica glass to put in front of the camera. The NEX-7 is physically set up in a way that allows us to mount it to our Imatest set up, and we happened to have most of the new lenses in stock one day, so I thought I’d take advantage of the situation to do some resolution testing. (Because I know someone will ask, we can’t test many of the small cameras because mounting to our tripod system blocks the memory card door. It takes 10 to 20 test shots to align the test setup. But if you have to unmount from the tripod mount, you have to start over. So it’s not possible for us to test some camera systems.)

The usual “don’t read this stuff and go insane” cautions apply: this is a test of lens and sensor resolution done at a distance of 10 to 30 feet, depending on focal length. The results might be different at 4 feet or 400 feet. Focus is done manually and bracketed so it’s not a test of a camera’s autofocus ability. The tests use a controlled-lighting test-target with a hardware mounted camera and Imatest software at ISO 400, so photos taken in the dark of night or hand-held for 12 second exposures will give slightly different results. It doesn’t measure autofocus speed, lens size, manual focus feel, bokeh, color rendition or anything like that.

The Lenses

Still the results are interesting and I suspect none of you would pick one of the eventual resolution co-champions out of the lenses we tested:

Leica 50mm f/1.4 Summilux on a Fotodiox adapter (picked because it’s the highest resolution 50mm lens we’ve tested on other bodies).

Sony 18-55mm and 18-200mm E-mounts zooms both tested at 30mm because that was our original point of interest. That was probably the sweet spot for the 18-55, but may have handicapped the 18-200 a bit: it seems better around 50-90mm. But certainly it’s better at 30mm than at the long end.

Sony 16mm f/2.8; 24mm f/1.8; 30mm f/3.5 Macro and 50mm f/1.8 E mount prime lenses.

Sigma 19mm f/2.8 and 30mm f/2.8 E mount lenses.

Unfortunately we did not have a 55-210 Sony zoom in stock at the time of the tests.

Imatest Results

The values are for MTF-50 (which correlates with fine detail resolution) measured in line pairs / image height. The first (higher) number is the MTF 50 measured at the center of the lens only. The second (lower) number is the average of the MTF-50 measured at 13 points including the center, 4 corners, 4 sides, and 4 mid points.

The first graph shows the numbers for each of our lenses (zooms measured at 30mm) with the lens wide open. This test isn’t a level playing field, since some lenses are f/4 wide open (the zooms) while the primes are at anything from f/1.4 to f/3.5. But since some people tend to shoot every lens wide open, it may be useful to them. Please note: On Monday, May 7th I retested a number of Sony-Zeiss 24mm f/1.8 lenses because the initial two we tested seemed strange, and were very close in SN (it’s all we had in stock at the time). I’ve since repeated that test with different copies and the new results at f/1.8 are much better. I’ve changed the results below to reflect the better results — here’s a good example of tests of one copy of a lens, even two copies, is never enough to base your decision on. We’ve examined the copies from the original test carefully and other than the softness at f/1.8 (which is gone by f/2.2) we still haven’t figured out what problem they have.

MTF 50 at Widest Aperture

We can level the playing field a little bit by shooting the wide primes at f/2.8. That gives us the numbers below. It’s somewhat more meaningful: the zooms are still f/4 and the Sony 30mm Macro at f/3.5, but everything else is shot at f/2.8 here. Notice the results for the little, reasonably priced Sigma 30mm f/2.8 are in bold. While some lenses are close to as sharp in the center, nothing is nearly as good in the corners. Impressive.

MTF 50 at f/2.8

We can level things out a bit more by shooting all of the lenses at f/4. Most of the lenses would get a bit sharper still at f/5.6, especially in the average number. Notice the Sony 24mm f/1.8 has gone from easily the worst resolution to among the best (at least in the center) by stopping down a bit. It really was much, much better at f/2.0 so I would consider that the real maximum aperture for that lens. (We checked a second copy and it was exactly the same – it’s possible that we had two copies that were bad at f/1.8 and not at f/2.0, but I really, really doubt it. I’ll check a couple of others when they get back from rental to be certain.) Really only the Sony 50mm and the zooms are lagging behind in the center, and the Sony 16mm pancake does, of course, still suck.

MTF 50 at f/4

Comparing Lenses

Imatest is measuring the resolution of the lens-camera combination (as opposed to an optical bench, which measures the lens’ maximum using collimated laser or LED lighting). We chose the Leica 50mm f/1.4 Summilux because we’ve tested it on a lot of other camera systems and know the lens is as good as it gets from a resolution standpoint. That the Sigma 30mm, a $200 lens, is keeping pace with it is really amazing. Obviously it’s not really a wide aperture prime, with a maximum aperture of f/2.8, but it gives world-class resolution. The Sony 24mm f/1.8 is not the bargain the Sigma is, but from f/2.2 on it has amazing center resolution, although it lags behind the other two in the corners. The Sony 50mm f/1.8 appears to be tuned like the Nikon 50mm f/1.4 G: it’s not quite as sharp in the center, but keeps good resolution across the entire front of the lens. Notice it’s average resolution is up there with the 3 best lenes, although the center isn’t quite as sharp as the other primes.

The Sony 30mm Macro may be better at Macro distances (should be actually), but the Imatest setup requires us testing it at about 15 feet distance. Very decent also describes the Sigma 19mm f/2.8 which is clearly far better than Sony’s 16mm pancake. The zooms, well, they’re about what we thought: OK lenses for when you need a zoom.

Comparing Systems

It’s always a little complex to compare Imatest resolution between cameras with different sensor sizes, since the numbers we generate are measured in line pairs / image height, and image height differs.  I hesitated to do it at all, because it will inevitably lead to 716 posts about whether it’s most appropriate to multiply the resolution of the crop sensor of divide the resolution of the full frame, and by what amount. But my thought is to keep it simple. If I take a picture of a building with whatever camera I’m shooting so that it is the same size on the image I print, then image height of the sensor doesn’t matter.

In other words the printer doesn’t care what size the sensor that took the picture was if the pictures were the same. Given this ‘Roger Rule’ the results with the NEX – 7 and good lenses are about what we’d expect: resolution at f/4 with a good lens is about what we see with a Canon 5DII or III (1050 / 800 or so LP/IH) with a good lens, not quite as good as a Nikon D800 (1200 / 1000 LP / IH). So shooting with one of the better lenses  listed above you can certainly get all the resolution you should ever need.

If you want to shoot a zoom, though, things aren’t so pretty. For example, a Nikon 24-70 f/2.8 shot at f/2.8 gives around 890/830 jumping up to 940 / 875 at f/4. A Canon 70-200 f/4 resolves at 920 / 845 at f/4. The Sony zooms are both about 855 / 660, which means the corners of a good Canon or Nikon zoom are about as sharp as the center on the Sony E zooms. Those are more expensive zooms, no question. I’m not trying to compare apples and oranges. Simply stating that the NEX system doesn’t offer a high quality zoom and giving some examples of what a high-quality zoom’s numbers would be like.

But for prime lenses, at least, we’re now getting some good quality, native mount lenses to put on NEX cameras without an adapter. My hat is off to Sigma for making a couple of really good lenses at amazingly good prices. Well done! Hopefully as the user base of E mount cameras increases we’ll start to see more third party options.

Roger Cicala

Lensrentals.com

April 2012

]]> http://www.lensrentals.com/blog/2012/04/nex-7-lens-imatest-resolution-comparison/feed 25 http://www.lensrentals.com/blog/2012/04/quick-tamron-24-70-mtf-data http://www.lensrentals.com/blog/2012/04/quick-tamron-24-70-mtf-data#comments Fri, 27 Apr 2012 20:06:19 +0000 Roger Cicala http://www.lensrentals.com/blog/?p=6583 We got a couple of Tamron 24-70 f/2.8 VC in Canon mount today and I was able to compare them, very briefly, with the Canon 24-70 f/2.8 L.

The Tamron is not quite the range of the Canon on the long end, clearly a few mm shorter than Canon (which is clearly a couple of mm short of 70mm). For anyone who doesn’t know, manufacturers “round” up or down to give the numbers they actually put on the zoom. I can’t see where being a bit shorter is going to affect anyone very much.

Autofocus is reasonably fast, although the Canon may be a bit quicker. Nothing dramatic like the Tamron 70-300 (which was horribly slow), though. Again, I can’t see this making a ton of difference to anyone.

Imatest results were clearly in favor of the Tamron, though, at both the long and short ends. I was able to run 3 copies of the Tamron on 2 cameras and results were as consistent as we’d like them to be.

These are MTF 50 results (3 copies of each lens tested, best results of each copy averaged, variation +/- 2.5%) measured in line pairs / Image height on 5D Mk II test cameras from unsharpened raw files.  Ctr = the Center Point, Avg =  a weighted average at 13 points on the lens (center, 4 mid 1/3, 4 corners, top and bottom) The Tamron is clearly better on the wide end, particularly in the average number across the entire lens. At 70mm the centers are about the same (you couldn’t see that difference, even in reasonably sized prints), but the average across the lens is again better with the Tammie

The Lens sharpens up even further at f/4, and a bit more, particularly in the corners at f/5.6 as shown in the graph below.

MTF 50 improves to f/4 in the center and f/5.6 in the corners.

So what does this all mean? It means the lens has potential to be good. We’ll have to wait until some real world results and reputable reviews come in to get some real-world initial impressions.

The First Images

The very first cameras, of course, were Daguerrotypes and the images they made were positives on silver plates coated with Iodine and developed using fumes from Mercury. You can probably already tell this had a few drawbacks. Positive images can’t be reproduced so one picture was one picture — if you wanted a copy for Aunt Bessie  you had to take another picture. Silver is silver, so each picture was rather pricey (up to a month’s pay for a working man). I guess inhaling mercury fumes in the darkroom all day didn’t exactly lead to a lot of healthy old photographers walking around either.

Not long after that, the albumin process was developed. This let photographers make negative images on glass plates coated with albumen. Glass is a lot cheaper than silver, which helped make photographs affordable. Since the images were negatives you could make as many prints as you might like from a single photograph, so things like picture books came into being. Images on glass could be projected in ‘magic lanterns’ so risque images of  ladies ankles and such could be projected at the gentleman’s clubs of the day. So the albumen process made it possible for photographers to achieve the same goals they have today: getting published in book form and getting pretty girls to pose partially undressed.

Albumin had it’s drawbacks, though. The process was difficult and time consuming, requiring the plates to be prepared fresh just before each photographic shot. Carrying around a few hundred glass plates got rather heavy, and glass breaks. And the major source of albumen, in case you don’t know, is from egg whites. Photography became so popular that it actually led to egg shortages. As many as 1,000,000 eggs a year were used for photography in England alone.

Cellulose, Nitrocellulose, and Collodion

Oddly enough, the same year that Daguerre introduced the camera (1838) another Frenchman, Anselme Payen, discovered that a chemical called cellulose was the major structural component of most plants. Everything from cotton to wood was largely cellulose, in slightly different variations. Other chemists quickly found out that cellulose was a huge molecule, but made up of a small molecule (glucose) linked over-and-over into long chains.

Chemical diagram of two glucose molecules linked together, like they are in cellulose. A single cellulose molecule is made up of from 50 to many hundred glucose molecules.

I promise not to go all chemical formula on you in this article, but it’s easier to show you a picture. The hexagon in the middle of each glucose molecule is a ring of carbon atoms, and you can see there are various atoms (Oxygen and Hydrogen) sticking out from the ring. The reason chemists were all pumped about this was if you made a chemical change to cellulose, you’d be making that change to hundreds of atoms that were linked together. Cellulose is available in everything from wood to cotton, so if  you made some useful new chemical from it, you’d be able to get your starting supplies very cheaply. That’s always a good thing.

Schonbein and Exploding Cotton

Frederich Schonbein was a Professor of Chemistry at the University of Basel. He was also a complete chemistry geek. Working in the lab at the University all day wasn’t enough for Frederich, he liked to do some experimenting at home after dinner and on the weekends. Frederich’s wife had gotten pretty tired of this and forbidden him to do any more chemistry experiments at the house. But wive’s will be wive’s and go visit their sisters, and men will be men and use such opportunities to do what they are forbidden to do.

Frederich decided to take advantage of his afternoon home alone to play with Nitric Acid and some other fun things. Of course, given the karma debt this caused, he spilled the acid on the kitchen floor and grabbed his wife’s cotton apron to mop it up with. He hung the apron over the stove to dry, no doubt checking his watch to see how much time he had before the little lady got home. He needn’t have bothered: the apron exploded rather violently, blowing the windows out of the kitchen and causing various other damage.

History didn’t record the discussion Frederich and his wife had when she got home. But it does record that Frederich had accidentally discovered guncotton. The Nitric Acid had converted all of the Oxygen-hydrogen (OH) side chains to Nitrate side chains – the cellulose was now nitrocellulose (AKA Guncotton) which just loves to explode. I can assure you this is so – I first read about guncotton in college and my geek friends and I snuck into the Organic Chemistry lab to make some. In case you ever want to know, chemistry lab windows cost $145.55 each and if you blow some out you have to pay for them before you can graduate. (If you feel the need to repeat my actions, there’s a link in the references that tells you how to make your own guncotton. But remember, this is a first step to becoming a Darwin Award winner.)

Nitrocellulose, AKA guncotton

Frederich, being German, immediately realized that there would be big money selling his guncotton to the military: it was more powerful than gunpowder and didn’t leave huge clouds of smoke like gunpowder did. He immediately attracted some venture capital and built factories to manufacture guncotton. Unfortunately for Frederich and his investors, one by one all of the factories exploded and they went bankrupt. Guncotton wasn’t all that safe to work with.

Collodion

Schonbein had been right, though. There was a huge market for guncotton if it could be made safe (safe explosive is kind of an oxymoron, but you know what I mean). Chemists all over the world began experimenting with cellulose and nitrates. They did make it safer, but they also learned other things. For instance, guncotton will dissolve in a solution of ether and alcohol, making a thick, syrupy liquid called collodion. When exposed to air it quickly dries to a plastic-like coating (you may have used it in products like “liquid bandage” or “compound W”).

Frederick Scott Archer, courtesy Wikepedia Commons.

Collodion was pretty cool and all, but other than instant bandages and making shiny coatings on things it didn’t appear to have a lot of uses. However, In 1850, Frederich Scott Archer found that collodion made a superb substitute for the albumen being used to coat glass plates for photography. Light sensitive chemicals dissolved in it easily, it coated plates smoothly, cost less than albumen, and it didn’t spoil (albumen comes from eggs – you know what 3 day old eggs smell like?). Most importantly it let people go back to using eggs for their natural purpose — breakfast.

The importance of Archer’s discovery really can’t be exaggerated. It became the primary way photographs were made by the mid 1850s. The process was further improved by W. B. Bolton and B. J. Sayce in the 1860s, making it somewhat simpler and more consistent.

It wasn’t perfect, of course. The plates had to be made by the photographer within 10 minutes or so of the exposure. It was sensitive only to blue light, so warm colors appear dark and cool colors light, so a person dressed in bright red or yellow would appear to be wearing dark clothes. Because clouds and sky are both shades of blue, clouds rarely are seen in collodion process images. Oh, I almost forgot — collodion is nitrocellulose (guncotton) suspended in ether and alcohol, so the odd fire or explosion did occur when preparing photographic plates.

A Photographer Discovers Synthetic Cloth

Toward the end of the collodion era, a French photographer, Hilaire de Chardonnet, spilled some of his collodion. When he cleaned up the partially dried puddle he noticed that the collodion pulled away in long, sticky threads. They reminded him of the threads of silkworms which he had seen as a student.

Hilaire de Chardonnet

Chardonnet tried forcing collodion through small holes drilled in a metal plate and found it made nice shiny threads that could be woven into cloth. He patented the process in 1885, showed his “Chardonnet silk” at the Paris exposition of 1889 to great acclaim, and opened factories to produce his marvelous new material in 1891.

Chardonnet Silk was very popular. For about a year. But Chardonnet forgot what we just talked about: collodion is largely nitrocellulose and so was the cloth he made from it. In one known incident a gentleman accidentally flicked a cigar ash on the dress of his dancing partner. Her entire gown disappeared in a blinding flash of light and heat, leaving them both with flashburns and the lady displaying more of her charms than she had intended.

Chardonnet was able to make changes to his chemical process (the fact that his original factory burned down in another nitrocellulose fire probably made it easier to make changes). By that time, however, other chemists had tried his “push a thick sticky substance through small holes to create threads” idea with other chemicals. One company found that viscose, which was created from the cellulose of wood chips, would make artificial threads just like collodion would, but with the advantage of not exploding. Viscose could not only be forced through small holes to make threads, it could be forced through thin slits to make sheets. The American Viscose Company and the Fibersilk Company produced both the cloth (which we call Rayon) and the sheets (Cellophane). The company made a major fortune and is still around today, although now it is known as the DuPont Corporation.

Dry Plates and Early Film

Despite it’s drawbacks and complexity, wet plate photography had a long life by today’s standards, over 20 years. Photographers, then, as now, were always searching for a better way, though. In the early 1870s, R.L. Maddox began putting silver bromide in a layer of gelatin on glass plates, and letting it dry — the birth of dry plate photography. It wasn’t popular at first, but a few years later Charles Harper Bennett found that heating the plates made them more stable and more light sensitive. Then, as now, increased light sensitivity attracts photographers like moths to a candle. Within a year or two, dry plate photography had largely replaced the collodion process.

In 1879, George Eastman invented a coating machine that mass produced dry plates. Suddenly photography became something people could do without years of training. Now there was no need to spend several minutes preparing a plate before taking a single photograph, you just unwrapped a dry plate and popped it in the camera. Eastman then had the brilliant idea of coating his gelatin emulsion on rolls of paper instead of sheets of glass. Since it had a paper backing, this first film wasn’t transparent like more modern film. After exposure the gelatin film layer was stripped from the paper, coated with (guess what?) collodion, forming a transparent negative that could be used to make prints.

Eastman was rather shocked that professional photographers didn’t flock to his paper film, but professionals seemed very threatened by the idea that someone without lengthy training would be able to make photographs. Charles Dodson (AKA Lewis Carroll) was, in addition to being an author, one of the premier portrait photographers of the wet plate era When he first saw the new dry plates, his only remark was “Here comes the rabble”. He stopped taking photographs entirely a year later.

Alice Lidell photographed by Charles Dodson. She was the Alice who inspired Alice in Wonderland.

Eastman was a shrewd businessman and realized for every professional already taking pictures, there were dozens of nonprofessionals who wanted to. He marketed his invention to the masses, making small, self-contained cameras that people could use with virtually no training. They could even send him their film for development and printing. Eastman named his company Kodak because he liked the letter ‘K’, he felt the name could not be mispronounced, and it didn’t resemble any word used in photography at that time. He wanted everyone to know his company was completely different from the photography suppliers of the day.

Celluloid

Gelatin films had the nice advantage of not exploding, but we photographers apparently just can’t leave exploding stuff alone. Especially nitrocellulose, there’s just something about guncotton that apparently attracts us. Way back in 1855 Alexander Parkes discovered that if you could dissolve your guncotton in camphor (instead of ether and alcohol) you got a thick gel that you could mold into almost any shape, which would then dry to a strong solid. By some definitions, this was the first plastic.

Being a modest man, Parkes called the substance Parkesine and started a company to manufacture and market it. Probably because of the awful name, he went bankrupt. He gave his patents to a friend, Daniel Spill, and apparently also sold them to John Hyatt, who had also independently developed a similar substance and also patented that. Both men went on to successfully market the same product as Xylonite and Celluloid, respectively. They both were successful, made lots of money, and entertained themselves by suing each other over patent rights for the next decade.

Hyatt’s first use of celluloid was the manufacture of billiard balls (I know what you’re thinking, but really this does have some relation to photography. Hang on for a minute.) Until that time billiard balls were made of ivory which made them rather expensive (this was way before PETA and the EPA, so expense was considered the only drawback to ivory billiard balls). Celluloid billiard balls were wildly successful and billiards moved from the parlors of rich men to taverns and sleazy corner pool halls where we enjoy it today. Celluloid billiard balls did have a downside, however. Celluloid is still largely made from nitrocellulose (guncotton), so if you hit the balls a bit too hard . . . .

The photographic world also saw the potential in celluloid and both George Eastman’s Kodak Company and a gentleman named Hannibal Goodwin patented methods for making photographic film on flexible sheets of celluloid. By 1889 Eastman had developed commercial roll film and along with Thomas Edison’s invention of the Kinetoscope in 1891 and Louis Lumiere’s Cinematographe in 1895, motion pictures were born. Mr. Goodwin, unfortunately, did not get the patent for his invention until 1898. He started his own film company, but died before he began production. His heirs did quite well, however, suing the Kodak company for patent infringement and receiving the amazing sum of $5,000,000 in 1914. Of course, by that time, writing a check for $5,000,000 was petty cash for Kodak.

Unfortunately, however, history does tend to repeat itself. Once again, photographers were playing with stuff made from nitrocellulose, and once again, bad things would happen. In 1897 the celluloid film being shown in a Paris movie theatre caught fire, burning the theatre to the ground and killing 120 patrons. This caused some countries to require that movie theaters line projection booths with tin and lock the projectionist inside so if the film burst into flames, there was no chance of the fire spreading. I assume this is when projectionists started getting paid more than the kids selling popcorn.

Safe Film and the End of Nitrocellulose

Despite it’s risk, celluloid film had so many advantages that it was the main type of photographic and motion picture film used until the 1930s. A different, but similar, chemical, cellulose acetate had been developed in 1904 and the Kodak company actually bought patents and manufactured film from it as early as 1908. It was more expensive than celluloid film and a bit more difficult to work with, so it was not particularly successful. It became easier to manufacture and less expensive in the 1920. Marketed as ‘safety film’, because it would melt, but not burn, when exposed to fire, cellulose acetate had largely replaced flammable celluloid by the 1930s. The ‘celluloid’ name remained in common use for decades, however.

Photography had done a lot to keep dangerous nitrocellulose in common use, so its probably fitting that photography helped end it’s use (other than for college pranks and some purposeful explosions). In the early 1900s, a Belgian chemist named Leo Baekeland emigrated to the United States, hoping to make his fortune from chemical inventions. He was unsuccessful for some years, but in 1893 he invented a new type of photographic paper that eliminated the washing and heating steps needed to develop prints. He was nearly bankrupt by this time and approached George Eastman, asking $50,000 for the patents (but having told friends he would happily take $25,000). Eastman immediately offered the amazing sum of $750,000 for Baekeland’s patents.

Baekeland, being no fool, took the money and bought himself a first class chemistry laboratory (and a house and probably some stuff for his wife). In 1907 he produced the first real plastic, which he called Bakelite. Within a few years, Bakelite had a thousand uses: it was an artificial shellac, the major insulator in all electrical appliances, made up most nonmetallic car parts, handles for kitchen equipment, plates and dishes, even knobs and telephones. It never exploded and really didn’t even burn easily. Bakelite was THE plastic for a generation. Today it has largely been replaced by newer plastics, but it’s still used as electrical insulator. And it has one other use that continues to make it popular to this day: Bakelite is the substance used to make non-exploding billiard balls.

Roger Cicala

Lensrentals.com

April, 2012

Referemces:

Helmenstine, A. M: http://chemistry.about.com/b/2012/02/18/make-nitrocellulose-or-flash-paper.htm

Ths History of Kodak. http://www.kodak.com/ek/US/en/Our_Company/History_of_Kodak/Imaging-_the_basics.htm

Le Couteur and Burreson: Napoleon’s Buttons: 17 Molecules that Changed History.  Chapter 3: Cellulose. Penguin Press, 2004.

Lauer and Robinson: The History of Celluloid. Plastics Historical.

Lienhard, J. H.: Collodion. http://www.uh.edu/engines/epi608.htm

Wikepedia: Collodion Process: http://en.wikipedia.org/wiki/Collodion_process

Wikepedia: Celluloid: http://en.wikipedia.org/wiki/Celluloid

Wikepedia: History of Film: http://en.wikipedia.org/wiki/Photographic_film

Almost since the day we launched the current version of our website, we’ve been working on its replacement. We are very excited to announce that we will be launching our new website very soon. While our website has been rebuilt from the ground up, you won’t find the changes confusing. We’ve worked hard to build a site that lets you find the gear you need and the information you need, faster. It will be cleaner, simpler, and more organized than ever before. So if you come to our site some day soon and everything looks different, it’s still us, we’ve just gotten a facelift.

New Carrier

In conjunction with our website launch, we are excited to announce we are changing our default shipping carrier to FedEx. Being located in Memphis, we are just across town from the FedEx SuperHub. We hope this will give us even more reliability in our shipments, because we know how critical an on-time arrival is to all of our customers. Another advantage of using FedEx is that we will be able to have our packages picked up at a later time in the evening, which we hope translates into pushing back our order cut-off from 4:00 CT to a later time of day.

We know not everyone prefers FedEx, so we are not doing away with UPS shipping. We’ve designed our new website to allow you to change to UPS shipping with a simple click of the mouse.

To avoid any confusion, we won’t be modifying the shipping methods for any orders that are reserved before our new site rolls out. So simply, if our website, and your order confirmation email says your order is shipping via UPS, then your order will still ship via UPS, even after we make the change to FedEx as our default carrier.

But not being total idiots, we didn’t completely take it apart like we did with the NEX or D7000 camera. So this is only a strip-tease, not a strip down. But it’s still fun (and educational too!!!). One thing that is readily apparent: I made the comment when the camera first came out that this could well have been named the 6D, it was really different than the 5DII. Nobody else seems to think so, but looking inside confirms what I thought: inside this camera is largely redesigned and it’s one of those where I want to compliment the engineers. This camera is beautiful inside, logically laid out and well built.

The Usual Disclaimer Stuff

First things first: if your camera is in one piece, then leave it alone. We’re semi-trained, semi-professionals with another 80 of these on the shelf. If we screw it up, we’ll only have 79 left, which is probably less critical than if you screw up the only one you have and then need to ‘splain to your wife why you have to buy a new camera. (And for those of you wondering if we got in trouble for doing this – no, we had it completely reassembled before Tyler and Drew got back from lunch. They’ll never know about it.)

So Let’s Have a Look!

Aaron started the disassembly while I went looking for a macro lens, so by the time I got back he’d already peeled off the grips, removed 20 odd screws, and opened the case  (Aaron just likes to show off sometimes). Differences from the 5D II are immediately apparent: there is only a single flex attaching the back assembly to the main board, and one flex and a wire harness from the top assembly. The circuit boards and flexes for both the camera body and back are covered with black rubberized sticky plastic, protecting things inside (and possibly adding some electrical shielding). I haven’t seen this on other cameras, it’s a very reassuring thing (and may explain why the loose screw didn’t short anything out).

Looking more closely at the back, several other changes are apparent. All of the flexes take short, direct routes to where they are going. No long winding flexes stuck down hither on yon. There are also a lot more of the robust ‘plug-in’ type connectors and fewer of the ‘slide-and-lever-lock’ which (I know from unfortunate experience) are rather delicate. There are also several places where wiring harnesses (look at the upper left corner of the main circuit board) are used rather than flexes. They’re certainly sturdier and (I assume) provide better electrical insulation.

Looking at the front of the camera, it’s again notable how clean and organized everything is. No long wires running here and there. Wire pairs are nicely braided and there are grooves and hooks in the plastic to keep them in place. That’s a nice touch that you don’t often see.

Another minor, but very nice touch that shows how carefully this design was thought out: the battery latch is right at the front of the compartment as an easily replaced screwed in assembly. On other cameras (including the 5D II) it requires major disassembly to replace a broken battery latch, which is a common repair. This one can be done in minutes.

Looking at the top, there’s nothing remarkable except more of the same: everything is neatly laid out in it’s place with minimal wiring and connections.

Going back to the back of the camera, the sticky plastic protective sheet pulls up easily. As an aside it already has shown it’s worth: the loose screw was in the crease along the edge of the plastic sheeting – the sheeting kept it from shorting out anything on the circuit board.

With the sheeting removed you get a really good look at just how well this camera’s electronics are laid out: every flex run is short and direct, insulated wiring harnesses are used in several places, and heavy-duty plug-in connectors are used more frequently than I’ve seen on any other camera.

The difference in connections is obvious in this close up. Slide-in flexes (held up by the forceps) are used in almost every connection in most cameras. The heavy-duty plug in type on the left and thickly insulated wiring harnesses (deeper and between the two connectors) I’ve rarely seen except in this camera and Pro (1D xxx or D xxx) bodies.

You can see another nice touch if you look at the two large flex connectors between the main board on the left, and the smaller board on the right (in the image of the entire back, above). The right board contains the SD card (lifted up, on top in the image below) and CF card slot (underneath). CF pins break frequently and if they can’t be resoldered can require a main circuit board replacement in a 5D II. On the III only the card assembly would require replacement. A very nice touch from an engineer who is thinking about future maintenance as well as the current camera.

A last close-up of the circuit board before we put this thing back together. The Digic 5+ chip is really rather huge. The chip above it is, I believe, DRAM, but I’ve no idea on the other two.

There is probably more goodness to see down deep in this camera. But Tyler and Drew were heading back from lunch, we’d found the missing screw and put it back where it belonged (it was one of 4 holding the card readers in place – the card reader’s were still firmly in place and wouldn’t have missed it but the rattling would have freaked someone out) so we thought it best to get things put back together before anyone noticed we’d taken it apart. It’ll be just our secret.

Ooops, I almost wrote an article without a lame pun. But I know what  you’re thinking: we must have a few screws loose to be opening a 5D III like this.

Roger Cicala

Lensrentals.com

April, 2012