Canon 5D Mark II wide angle lens sharpness issues

Canon 5D Mark II wide angle lens sharpness issues -- by Joe Reifer

Zeiss 21mm f/2.8 Distagon on a Canon 5D Mark II. (Click the image for a larger view).

Both images are 1/350 at f/11 ISO 200. Both are 100% crops (1:1 view) in Lightroom. The images have identical post-processing. So what’s the difference?

In the on the left the bridge is near the center of the frame, in the image on the right it’s along the right edge. After extensive focus testing, this copy of the Zeiss 21mm produced results that were consistently soft in the background about 10% of the way into the frame. Here’s the problem in a nutshell:

Camera and lens manufacturing tolerances may not be tight enough to produce consistently sharp results with wide angle lenses on high-resolution cameras like the Canon 5D Mark II.

I’ve now tested 3 copies of the Zeiss 21mm f/2.8 and 2 copies of the Canon 24mm TS-E II, and only 1 out of the 5 lenses was acceptably sharp across the frame. Unfortunately, the 1 lens that was sharp was a rental. Three of the lenses were soft on the left edge of the frame in the background at f/8-f/11, and the Zeiss above had the same issue but on the right side.

The Zeiss 21mm and Canon 24mm TS-E II are both extremely sharp lenses, which seems to exacerbate the problem. The mountains in some of the photos I took yesterday were very sharp everywhere except the right 10-15% of the frame. Because everything else is so sharp, this makes the out of focus area even more apparent.

If you enjoy shooting with wide angle lenses and make large prints, this may end up being a problem for you sooner or later with high resolution 35mm digital. If you’re thinking about upgrading to a 5D Mark II, or buying a new wide angle lens, here’s a very important article to read:

“This lens is soft” and other facts — by Roger Cicala of LensRentals.com

In addition to the excellent article above, Lloyd Chambers’ subscription site has some informative articles including Brand new blur and Testing Guidelines.

The bottom line: buy from a vendor with a good return / exchange policy, and carefully test any lenses after purchase to make sure they’re sharp on your camera body.

8 thoughts on “Canon 5D Mark II wide angle lens sharpness issues”

  1. Interesting read. I’m sort of tempted to say “who cares, really?” My 16-35 II is soft on the edges and I’ve still printed 36×24 with great results. Is it soft in that area? Sure. Did a single viewer of my print notice? None that told me so. If you’re a great photographer (and you are), then I call shenanigans on worrying about this. People are going to care about great color, composition and subject. Only a subset of photographers are going to pixel peep.

    1. Hey Cody – I understand your sentiments. Content is king. Heck, Troy is making 24×36′s from a 20D that look great. That being said, I have a logic issue with putting a $1700 lens on a $2500 camera and not getting pictures that are sharp across the frame. I saved up to get the best wide angle lens possible, and I’m disappointed with the results. I want the camera and lens manufacturers to do better. While I’m waiting for that to happen, I’ll go take photos with my little Olympus 21mm and be happy. Hope you have a great full moon! – Joe

  2. That’s fair! I didn’t mean to come off as a curmudgeon in my first comment. Do you think it’s possible to get better results from lenses given the current resolving power of bodies? I wonder if anyone has tried a similar test with a medium format body. I just re-read your post. I admit the following does trouble me some:

    “Because everything else is so sharp, this makes the out of focus area even more apparent.”

    I’d be irritated at that, too, I think. Do you have a full frame example?

    1. I didn’t take it as curmudgeonly at all. And it takes one to know one. Your comment helped me think about this stuff a bit more, which is what this blog thing here is supposed to do.

      Phase 1: When full frame digital got to 11-12 MP, Canon’s wide angle zooms weren’t up to the potential of the sensors if you were picky about the corners.

      Phase 2: With full frame digital at 21-24 MP, and a very sharp wide angle lens, the fault tolerance for lens, sensor, or lens mount alignment can potentially lead to images that are softer on one side of the frame.

      I went part way down the rabbit hole in Phase 1 and I’m glad I did — shooting with manual focus lenses for night photography makes focusing easy, leads to a consistency in framing, and allowed me to experiment with the “drawing styles” of alternative glass. Unfortunately I’m not seeing any benefits to going down the rabbit hole in Phase 2.

      I actually have made one print where I spent a long time selectively blurring the mountains in the background to match the out of focus area created by this alignment issue. Subtle work, but I want to make the best prints I can.

      In a perfect world, the equipment would mostly disappear from the process.

  3. I work part-time at a southern-ontario camera shop, and we’ve run into a similar phenomenon with a large variety of lenses. In particular, it’s been an issue with 50mm 1.8s (total grab bag – some are razor sharp, others not so much), and, as you pointed out, wide angle and crop-sensor “ultrawides”. Tokina’s 11-16 is pretty miserable, I think maybe five out of six are soft across the frame. (Sigma’s 10-20 is very good, incidently). The last-gen nikon 12-24 was 50/50 whether it would have horrible softness and colour aberration around the 10-15% outer edge of the frame.

    I came across this when I started printing composite images around 90″x44″, and was noticing some serious softness issues when pushing my poor little 12mp S5 to that kind of enlargement. I’ve managed to tweak a 20 year old nikon 20mm 2.8 and a sigma 10-20 into good shape for this tho, it just, like all things, depends a lot on some alchemy of f.stop and focal length.

    Nonetheless, this has always been a problem, especially when you sell several thousand dollars worth of equipment to a pro photographer, and they’re bringing it back a week later with a legitimate concern, IMHO: “I didn’t spend six grand on this lens to have soft focus”

    1. Hi Matt –

      Thanks for your behind the scenes info on this issue. I didn’t realize the Tokina 11-16 had such issues. As cameras get more megapixels, the demands on the optics and manufacturing tolerances will get more precise, especially for the wide angles. Either that, or it’s back to using a Mamiya 7 and 43mm.

    1. Hi Dirk –

      Thanks for linking to your lens testing. My German is really rusty, but the results are pretty clear. If the Canon 17-40 is stomping an expensive Zeiss prime, something is definitely wrong.

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