We had a chance a few days ago to look at the first copy of the Zeiss 135mm APO-Sonnar CP.2 lens, but today received several copies of the 135mm APO-Sonnar in ZE (Canon) mount. I’ve been wanting to play with it personally, of course, but more to the point wanted the chance to test multiple copies, which always makes me feel better about out test results. I also wanted to compare its direct competitor, the Canon 135mm f/2L. Continue reading
Of course, being a photo guy who loves shooting at 135mm, I can’t wait to get my hands on the photo version of the new Zeiss 135mm lens. I don’t have that yet, but we did get the CP.2 Cine version of the lens, the Zeiss CP.2 135mm T2.1 in today. In addition to making our video shooters all drool, the CP.2 gave us a nice preview of the coming photo lenses.
This will probably be of limited interest to most of you, but we like to know how things work, not just how well they work. Since we haven’t had any lenses or cameras to take apart lately, we thought we’d take a couple of pictures when we disassembled a ballhead in case any of you were interested. Our demonstration partner today was a Benro B1 ballhead that had a stripped tension adjustment knob, but all ballheads work basically the same way.
Unlike most photography gear, ballheads are elegantly simple. They have only a few parts. There’s the ball itself, of course, and the external case. Between the ball and the top of the case is a form fitting bearing. The bearing material (not visible in photo) is a firm plastic that has low friction, but it distorts a bit with pressure, exerting more friction at higher pressures. Many balls, like this one, have an opening in the bottom. Continue reading
Ah, as if the 70-200 zoom field wasn’t crowded enough, with each camera maker having one or four along with the Tamron 70-200 f/2.8 VC and the Sigma 70-200 f/2.8 OS, but Tyler decided we have to stock yet another one. So today I have to test yet another 70-200mm, the Zeiss 70-200 T2.9 CP.2.
Obviously I’m a gearhead, so I like to know the traits of the lenses I shoot with. I want to know what aperture gives maximal corner sharpness, for example, whether the plane of focus is curved or flat, where the distortion changes in a zoom, which end of the zoom range or focusing distance is the lens sharper at, and a number of other things you may not care a bit about.
Does it improve my composition and technique? No. But knowing this stuff can be helpful. For example, when I want to shoot a landscape at 70mm and f/5.6 will my corners be sharper with my 24-70 f/2.8 or a 70-200 f/2.8? Or which will have less distortion for an architectural shot (since I hate the resolution loss of correcting distortion in post), my 35mm f/1.4 or my 24-70 zoom at 35mm? (Surprisingly, the answer is my zoom.)
This kind of information is easy to find. DxoMark has nice graphs for each lens that show distortion, vignetting, chromatic aberration, and resolution at various focal lengths and apertures for each lens they test. SLRgear.com has a nice pop-up app that shows the resolution across the field of the lens at various apertures and focal lengths. The Digital Picture has great pop-ups that let you compare two lenses side-by-side for flare, distortion, vignetting and even images of ISO 12233 crops.
A lot of people use those tools when deciding which lens to buy. I use them after I have the lens so I know how to best use it.
One thing that I’ve started using more frequently in post processing is a resolution map of the lens. We all know that every lens has highest resolution in the center and less in the corners. But the pattern of sharpness is different for different lenses.
Some lenses have a high peak of resolution right in the center that quickly drops off. Others maintain significantly high resolution halfway to the corners and then drop like a rock. Others have a rather linear drop-off from the center to the corners.
Just as an example, below are 6 Imatest charts showing MTF50 of 6 different lenses across the field of view. The absolute resolution numbers aren’t important for this demonstration, rather it’s the pattern of how the resolution changes. For each lens, yellow is the highest MTF50, blue is about 1/3 the value of yellow.
“Current camera sensor technology is completely backwards.” Dr. Eno Lirpa
Everyone knows that in order to generate color, a digital camera’s sensor is overlaid with a Bayer filter. The filter makes each pixel sensitive to either red, blue, or green light.
Software than interpolates this red, green and blue image into the final color image we see.
In effect, our 24-megapixel color camera doesn’t resolve any better than a 14 or 15 megapixel black-and-white camera would.
There have been several attempts to improve on the Bayer-array method of detecting color. The Foveon sensor, which stacks red, green and blue pixels at different depths at each pixel (sensor site), certainly provides higher resolution than a standard Bayer sensor, although the Foveon sensor has it’s own limitations.
Fuji has altered the array in their sensors, creating a more random pattern. This gives (arguably) some improvement over the standard Bayer array but still uses the same basic principle with inevitable loss of resolution.
At WPPI, I had the chance to spend time with the team from Baceolus Imaging, a small Italian imaging technology company with a growing patent portfolio and plans to make a big splash.
First and foremost, let’s be very clear: I am not a rangefinder shooter and certainly not a rangefinder reviewer. But I’m more excited than most people about the new Leica M (Typ 240) camera for one simple reason. It has live view and focus peaking so at long last I can, if I want, actually focus a Leica camera. (I have a vision problem that prevents me from focusing a rangefinder accurately.)
But like a lot of people I viewed Leica’s move to a CMOS sensor, rather than the CCD used in the Leica M9 and Leica M-E cameras, with a bit of trepidation. That 18-megapixel CCD had more resolution than one would expect from an 18-megapixel camera. Despite the sensors many limitations, I was concerned that a ‘modern’ 24-megapixel CMOS sensor might actually be a step backward on the resolution front. Continue reading
Nikon’s new Coolpix A camera has some impressive specifications, what with its 16 megapixel APS-C sensor, 18.5mm f/2.8 lens, and $1,100 price tag.
Nowhere in those specifications, though, is a claim for Vibration Reduction that I can find. But the packaging department apparently didn’t get the memo: the box sure claims it has VR.
Well, at least it has Target Finding Autofocus, where the camera picks out an autofocus point automatically. Wait a minute, every camera I’ve ever had has that feature — they all focus on what they want to, not where I put the focus selector.
Increasing vision is increasingly expensive. – R. A. Janek (actually Michael Crichton)
For the last year or so, it seems like almost every new lens release has been accompanied by sticker shock. The manufacturers are businessmen and they know when we’ve been salivating at the promise of a new wonder lens. They know we”ll be willing to (at least some of us) pay a ridiculous amount to put that slightly better lens in front of our camera.
Somewhat lost in the hundreds of Internet threads about whether this-or-that awesome lens is worth its ridiculous price, though, there are some good bargains to be had. In fact, right now there may be more excellent lens bargains available than at any time I can recall. But let’s define real bargains for a minute.
A bargain is NOT finding a $2,500 lens for $1,500. That is a scam and doesn’t happen in the real world. A bargain is finding a lens that does nearly as well as the best possible lens, or does some things every bit as well as the best possible lens, at a fraction of the cost.
In some cases, you can get a good bargain even if you limit yourself to the three-zooms-to-cover-every-boring-possible-focal-length kit. For others, getting a great bargain means leaving your comfort zone a bit; perhaps changing lenses more frequently, or correcting some distortion in post-processing. Doing this, though, especially if you are taking the first timid steps away from the ”three zooms” approach, may be the best thing that can happen to your photography. Continue reading
Well, for the first time I’ve totally caved to popular demand and done a test I had little interest in doing. But after I did a Quick-Take post on the new Nikon 80-400 AF-S VR lens I received about two-dozen emails and comments asking if the 70-200 f/2.8 AF-S VR II lens with a Nikon 2X III teleconverter was as good as, or better than, the new 800-400 AF-S VR.
My first impulse was to do Standard Internet Response #1 — give an absolute answer, such as ‘obviously not’, despite having no facts to back that answer up. Then I considered Standard Internet Response #3 — give a useless, but factual, answer like, ‘well, if you have a 70-200 and teleconverter already, that’s certainly adequate’. (I never use Standard Internet Response #2 – the ‘if you’re a good enough photographer it doesn’t matter which you use’ response, nor S.I.R. #4 — ‘Google is your friend’.)
But, since it really is a reasonable question and a lot of people seemed interested, we set up to Imatest the 70-200 f/2.8 VR II / 2X III combination. Please be aware that our longest testing distance is 40 feet, which isn’t ideal for testing 400mm lenses, but it’s the longest we have. (I’m pretty comfortable it’s a longer testing distance than anyone else has, too, except maybe DxO and they aren’t really sharing information about their testing set up). Results may be quite different at 300 feet. I’m not sure which way they’d be different. The 70-200 seems sharper at this distance than it does at infinity, at least that’s what most people say. On the other hand, teleconverters are generally tuned for long distance shooting. So I just don’t know. (BTW – “I don’t know” is not a listed S. I. R.)
We used an identical setup to the tests we ran last week on the 80-400 AF-S and 80-400 AF lenses to test the 70-200 f/2.8 with 2X combination. The MTF50 results are shown in the table below. The bottom line, from a resolution standpoint, the new 80-400 is clearly better. The previous 80-400 is better than the 70-200 with 2X right in the center, but outside the center the 70-200 with TC is very close.
Center MTF50 Avg MTF50 Avg. Corner MTF50
Nikon 80-400 AF-S 820 675 480
Nikon 80-400 AF 725 575 410
Nikon 70-200 f/2.8 with 2X 600 560 440
What does it mean? Mostly it means if you’re shooting at 40 feet distance the 70-200 VR II and 2x teleconverter will get you a nice usable image, but not as good as you would get with the 80-400 VR II.
The old 80-400 AF lens is better in the center than the 70-200 VR II combination, although that’s just right at the center. Less than 1/3 of the distance away from the center, the two are even.
I can’t say the results would be the same if the shooting distance was near infinity, and I’m not sure how they’d change. The 70-200 alone is reputed to be a bit less sharp at infinity, though. On the other hand, the teleconverter might well have less of an effect at the longer shooting distance.