Canon 50mm f/1.2

Ralph Eisenberg said:

In short, I'm in something of a conundrum about this lens, liking the image quality it delivers, but wishing that it would be more reliable in focus performance for the uses that I put it to.

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Ralph, that so accurately describes my feelings for this lens. I have seen somebody describe this lens as a "Jeckyll and Hyde" - it being a wonderful, creative imaging optic, but with fairly unreliable focus. I suspect we shall never get Canon to admit a problem with this lens, if one considers the extreme measures and long timespan it took to get Canon to say anything on the (very high-profile) 1DMkIII focus fiasco, so... what is a photographer to do but bite the bullet and treat it is a very, very expensive manual-focus lens.

Certainly, it is no more expensive than the best Leica/Zeiss 50mm lenses, not to mention the Nikon 58mm f/1.2 (when it was still produced) and I believe this lens to be capable of outperforming all of the above, with failures to do so being due to photographer or camera focusing error. The notorious Ken Rockwell certainly agrees with this

I certainly have no other lens that can do this at f/1.2: (click for large version)


Note: Though I also regularly experience autofocus inaccuracy, in this shot, the lens was perfectly focused on the point (badge) underneath the off-centre AF point I used. So it's not consistently out - which is worse, I guess. Either way, the in-focus area comfortably outresolves my camera wide open. Do you experience the same with your higher-resolution 1DsMkII?

Dawid Loubser said:

.... Either way, the in-focus area comfortably outresolves my camera wide open. Do you experience the same with your higher-resolution 1DsMkII?[/I]

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It is my informal impression that the lens can handle anything the 1Ds2 can throw at it resolution-wise, recognizing that the degree of detail is dependent on the Raw converter used. And I suspect that this would also be the case for the 1Ds3, given that Canon used an image taken with this lens to publicize the qualities of the camera.

Apparently, the focus micro-adjustments that are possible in the newer Canon camera bodies should allow one to make adjustments for a specific lens without affecting performance of the same body with other lenses, something that is not possible with the 1Ds2. As a highly capable, trustworthy and friendly Canon rep told me, this would make it easier to make adjustments for this lens. (This is the same person who had tried to disuade me from getting this lens).

Can the focusing screens on the 1-series bodies be changed easily and quickly?

Ralph Eisenberg said:

Can the focusing screens on the 1-series bodies be changed easily and quickly?

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In a matter of mere seconds, Ralph! Since "economising" my lens lineup to only contain f/2.8 and faster lenses, my camera permanently contains the Ec-L cross-split prism focusing screen, which I highly recommend in the linked post.

With the 50L: Though I do much prefer the Ec-L over the camera's standard focus screen, I must say that the screen seems to work much better on a f/2.8 lens than a f/1.2 lens! I want to try the Ec-S sometime.

Thanks Dawid for the information and the link.

I'll really have to look into these focusing screens and see how quickly I can acquire manual focus using them.

I brought my 50/1.2 in to CPS (Paris) to be checked. The technicians could not have been more helpful and kind. They noted the problems in close focusing that I was having with this lens using assigned peripheral AF points and took into account the fact that I was not encountering this difficulty with any other of my Canon lenses (35/1.4, 50/1.4, 85/1.2, 135/2, etc....). Regretably, the standard testing procedure for the lens is at a distance far greater than that at which I have been encountering this erratic focusing problem. In a sense, it excluded the difficulty. The lens was returned to me as being within specs with the offer to try to adjust it to my 1Ds2 body as best as possible. I decided to try the lens again and yesterday had the opportunity and priviledge to shoot in the atelier of the last existing master artisan in France in a field that is now entirely industrialized. To my dismay, the lens again failed me at a distance of about 1-1.5 meters, proving to be erratic and unreliable in the acquisition of focus using an assigned peripheral focusing point. The shooting conditions under which I used the lens could not have been more favorable and I did not have this problem with other lenses that I used, where I was far more reliably able to get accurate focus. I'm to hear from a Canon representative next week whether there are any plans for the the correction of this AF deficiency. If not, or if no information is forthcoming in this regard, I've decided to sell the lens with considerable regrets since, as I observed earlier in this thread, it draws beautifully and does have a special character to it.

Ralph Eisenberg said:

I'm to hear from a Canon representative next week whether there are any plans for the the correction of this AF deficiency.

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I don't think they can correct it, since it's an unfortunate design compromise. The lens apparently exhibits spherical aberration which causes a non-flat focus plane. This, combined with the AF sensor's native f/2.8 aperture, causes a mismatch which is most noticable at close range and wide open. It is a very good manual focus lens at close range though, although it might require a different focus screen to maximize the MF potential for such a wide aperture lens.

Bart

Hello Bart,

The design compromise that you speak of so well has received attention and comment. I did get the focusing screen, but I'm afraid that I don't have any confidence in my eyesight for the very precise focusing that low-light portraiture can require. But in any case, thanks for your observations.