With all the fuss about the 1Dmk3 and focussing, could you please update me as to the position with the 50L.....all the threads seem to have long since disappeared, and even a search turns up little. Thanks
Lord Fluff wrote:
With all the fuss about the 1Dmk3 and focussing, could you please update me as to the position with the 50L.....all the threads seem to have long since disappeared, and even a search turns up little. Thanks
The poll is missing a category of something like, "Has problem but have adapted to accomodate". I think one of the reasons people aren't that pleased with the lens (at least for anything close in) is this backfocus problem even if they aren't aware of it. Stopped down a bit the lens is really sharp but just not where you want it to be. Reports are that Canon service cannot fix it and if they attempt to they end up creating focus problems.at far distances. "Luckily" when I sent my lens in Canon said it was in spec so at least my lens is still usable if you know the limitations and adapt to them.
mine seems okay, but I've only briefly used it on a mark II n for testing and on my 1V. When my digital gets back I'll have the doubly difficult attempt to decide whetehr or not it has an issue... on a just-back- from- AF repair 1D mark III
I am in the "has a problem but have adapted to accommodate" category. This lens has beautiful color, contrast, bokeh, sharpness, and in every way is better than my 50 f/1.4... other than at close distances between about f/2 and f/5.6 you can note significant back-focus.
I sent the lens into Canon Irvine twice and neither time resulted in any notable improvement. Hopefully Canon will issue a statement and someday a fix, until then I will continue to work around its known limitations.
The lens has amazing color and superb clarity. To me, it is in the same category as the 85L, but with a slightly less pretty bookeh (probably due to the focal length). The 50L seems just a tad bit higher resolution, but I am not able to confirm this yet.
A lot of the issues can be blamed on shallow depth of field. If you try to hand hold the lens and shoot at f1.2, chances are you will miss focus. It takes time to get used to wide aperture lenses.
Some of the other issues brought to light by early adopters of the lens was the lens mises focus at smaller apertures f2.8 - f4.0 when the subject is around 3-4 feet away - or something along those lines. I am not sure if this is an issue with the lens or if this is something that the canon bodies need a firmware update for. Either way, I agree, canon has not cared to address this issue and I am sure it is frustrating to anyone who has invested $1600 in this lens.
I love mine and in the two months I have used it, I have yet to see any focus issues on it. It excels at what it is designed to do - a 50mm wide aperture lens - use it on a full frame and you see how good this lens really is.
I am still pondering which one of the two I would have to let go as I don't need two primes that are so close in focal length to each other. I sold the 35L as that was an easy choice - the 50L was perfect to replace it. Now I am thinking real hard as to which one would work better for me as I like them both. Chances are I will retain the 85L and let the 50L go only because I seldom use primes and I only need one.
All I see are resized images in that link. Even pretty soft lens can look sharp when resized that small. Is there anything there beside the photo slide of 15 re-sized images or so?
I only ask because I find a lot of nice qualities about the 50L, but I find it to be an average performer for sharpness (even manual focusing, yes, to account for the difficulty of focusing at apertures larger than f2.0/2.2). My 100 crop viewing of my images tells me that Canon's 35-85-135L lenses all out perform the 50L with respect to sharpness and contrast. And I haven't really seen any samples on the net that show me otherwise.
That said, sharpness and contrast aren't everything, and some post-processing and stopping down a bit help the lens a lot. And I'm just a guy who finds the 50mm field of view useful, as frustrating as the 50L can sometimes be.
If you need a lens that lets you look at 100% image size/crop view to see each individual pixel to determine if it is sharp, no lens is going to satisfy you.
A sharp picture is a sharp picture whether you view it in a small web size image or on a small 4x6 print or on a large lifesize print. You can tell when an image is sharp and when it is not.
If you need a lens you can shoot low light with and get a sharp print (I have gone up to 30" x 40" with the 1Ds + 50L), then the 35L, 50L, 85L, and 135L work perfectly.
It helps to understand why you need a large aperture lens like this. Two reasons that come to mind are for shallow depth of field with good background blur to isolate the subject thereby focusing attention to the subject AND/OR low light shooting without using flash. If you are going to use large aperture lenses for something other than this. you might as well save some $$$ and get something cheaper and smaller.
Got the 50/1.2 L and have not run into the problems people have been complaining about. Just a great piece of glass. Bokeh, contrast, color and shapness comparable to my 135/2 L.
I never used this lens, but would be interested in it if there weren't the "known problems". What interests me from a purely technical perspective, though, is how the lens can mis-focus stopped down but be fine wide open. Not from a DOF perspective, but from the point that it doesn't know at what aperture it will eventually fire. They all focus wide open, and exposure happens after focus is achieved.
stanj wrote:
What interests me from a purely technical perspective, though, is how the lens can mis-focus stopped down but be fine wide open. ...
Can anyone explain that?
Probably used the EOS 1D MKIII they were testing in the same issue on auto WB!
A full rez shot or two would have been nice. I guess they expect us to believe the SQF chart. Actually I have no doubt this lens would make a jim dandy 16x20 print.
The question however: if there's focus shift, how come other lenses don't exhibit this behavior due to focus shift? Again, the AF system doesn't know at what aperture the camera will fire so it's not like it's taking that into account with say the 85L and not the 50L.
For those new to the issues, the AF is dead on wide open or at 1.4, but at 2 or 2.8 there is focus shift causing significant backfocus at distances up to four feet or so. I'm learning to work around it. For example, in a portrait situation with subject's head slightly angled away from the camera, I would ordinarily focus carefully on the closer eye. If you want the look of the closer eye sharp and the other soft, using the very wide aperture capability will nail the shot. If you want both eyes sharp and set f/2.8, there's enough focus shift (optical, not an AF or mechanical issue), you'll likely find the far eye tack sharp and the near eye soft. My workaround is to focus on some strands of hair, the closest part of an eyebrow, whatever brings the focus slightly closer. This results in the DOF really centering around the two eyes, with both tack sharp (at 2.8, for a head and shoulders portrait).
Shouldn't have to do this, but I'll live with it until (I hope) Canon can devise a firmware fix that adjusts focus when aperture setting is changed. That's probably pie in the sky. Consider, though, that in the days of manual focus the real challenge was getting an occasional wide open shot with the focus right where you wanted it. With this lens on a good body, that can now happen with a good success rate.
I love the lens for its speed, amazing results from 1.2-2.0, resistance to flare, and build quality. I used it at a night swim meet where the light faded to the point that the 135/2.0 was no longer practical. The 50 L let me get right near the water without worrying, and I caught some shots at 1.2 that I couldn't have gotten with any other lens.
The question however: if there's focus shift, how come other lenses don't exhibit this behavior due to focus shift? Again, the AF system doesn't know at what aperture the camera will fire so it's not like it's taking that into account with say the 85L and not the 50L.
The issue seems to be that the 50L design hasn't accomodated for this while the 85L has.
What I'm most interested in is if what we're seeing is just copy variation or an actual design flaw. If it is a design flaw it's hard to imagine Canon didn't know about if. If some folks really have 50Ls that don't exhibit this issue then that points to many having got a bad copy that Canon should replace. Problem is I haven't really seen conclusive proof of a lens that doesn't exhibit this behavior. A lot of folks have said that is the case but I've also read of others that once they carefully tested their copy they discovered that their copy indeed had the problem. It does seem as if the amount of the issue may vary somewhat (or else the difference in the degree of the problem is due to variations in testing). Some have said the problem is mm others several inches. For me it is a bit less than an inch at 3 feet and f/2.8 (see 100% crop below; note that every 5 ticks are a cm).
http://www.pbase.com/tmr4/image/78630611.jpg
This isn't to say you can't get good shots with the lens. Many have shown this to be the case. I have also, even yesterday at the problem distance and aperture, though I typically avoid the problem apertures close in.
I guess time will tell. Reports were that Canon would make an announcement soon on this but that was about a month ago now so I'm not holding my breath.
