Dario Impini wrote:
I've just read this whole thread and man, this is a bummer. I believe I need a 50mm 1.2 for those dark weddings, but I've already been through AF hell with Canon using an earlier defective rig. I dont want to go through that again.
So let me ask you guys a couple questions -- can a close portrait problem be solved by focusing on the nose rather than the eyes? And is this only AF, e.g., can you manually focus and avoid this issue?
I've had the lens for a bit under a year and have tried all of the "fixes" including focusing on the nose (which isn't a suitable fix in many situations). The best method by far is using the outer AF points when close in and stopped down. Most folks probably do this by habit anyway and thus don't notice the issue. It isn't 100% for me but then that is probably more due to the lower accuracy of the AF outer points on my body and my technique. Still I get a lot more keepers this way than with the center AF point when shooting H&S shots with the 50L
- Lenses that consistently backfocus occur in all models and focus lengths. They should be calibrated. This does not indicate an inherent flaw in the lens design.
- It seems like the 50 1.2L has focus shift - a problem with some other ultrafast 50's - notably the Leica Noctilux - arguably considered the best 35mm format lens ever.
Focus shift is one of many optical flaws that the lens designer trys to (but can NEVER completely) design out of the lens. Another consideration is cost, the more correct the lens the more expensive. Every lens is a trade off between these flaws, cost, and capability. It is clear that many people really like the tradeoffs made for the 50 1.2L AND that many people don't.
For me personally, I would love to have a copy. I might prefer all the characteristics of the current lens without the focus shift, but maybe not if incorporation of the floating elements added a thousand bucks to the cost. Who buys a 50mm fast prime for performance at f2.8 anyway? Buy a zoom or the 50 1.8 for heavens sake. I use my 50 1.4 about 80 percent of the time at 1.4 or 1.8 and almost all the rest of the time at f8 and up.
Last thought - gosh, if you don't like the lens, don't buy it. Better yet, get your own lens company, hire a bunch of really smart optics designers and build your own fast 50 exactly the way you want it.
cwphoto wrote:
I couldn't MF anywhere near as fast or as accurate as AF - could you?
With good techniq manual focus can be quite quick most of the time. The big advantage of manual focus, however, is the ability to use the photographer's big brain rather than the camera's much smaller brain. Most photographers, after all, are much smarter than their camera.
- Lenses that consistently backfocus occur in all models and focus lengths. They should be calibrated. This does not indicate an inherent flaw in the lens design.
- It seems like the 50 1.2L has focus shift - a problem with some other ultrafast 50's - notably the Leica Noctilux - arguably considered the best 35mm format lens ever.
Focus shift is one of many optical flaws that the lens designer trys to (but can NEVER completely) design out of the lens. Another consideration is cost, the more correct the lens the more expensive. Every lens is a trade off between these flaws, cost, and capability. It is clear that many people really like the tradeoffs made for the 50 1.2L AND that many people don't.
For me personally, I would love to have a copy. I might prefer all the characteristics of the current lens without the focus shift, but maybe not if incorporation of the floating elements added a thousand bucks to the cost. Who buys a 50mm fast prime for performance at f2.8 anyway? Buy a zoom or the 50 1.8 for heavens sake. I use my 50 1.4 about 80 percent of the time at 1.4 or 1.8 and almost all the rest of the time at f8 and up.
Last thought - gosh, if you don't like the lens, don't buy it. Better yet, get your own lens company, hire a bunch of really smart optics designers and build your own fast 50 exactly the way you want it....Show more →
Good gosh, how about you bought the lens and expected it to work right?
Nothing personal but I just can't stand these posts that say "don't use it at f2.8". What utter B.S. You shoot at the f-stop you need for the shot. I'm not changing lenses just to shoot at a different aperture.
bcaslis wrote:
Good gosh, how about you bought the lens and expected it to work right?
Nothing personal but I just can't stand these posts that say "don't use it at f2.8". What utter B.S. You shoot at the f-stop you need for the shot. I'm not changing lenses just to shoot at a different aperture.
I think pretty clearl that the lens is going to focus shift at at close distances at f2.8, just like other lenses exhibit barrel distortion or flare or chromatic aberation, or.... The fact that a lens exhibits certain optical defect doesn't mean it doesn't "work right", it means it works to it's optical design. If you need a 50mm that is critically in-focus shooting 4 feet at f2.8 this lens is clearly not going to be for you. Me, I'd rather have the 50 1.2 with the better 1.2 performance as I couln't care less about 50mm at f2.8. To me, getting rid of my 50 1.4 not-quite-right look at f1.4 is much more important so I might really like the 1.2. I can see how you (and a lot of other folks) wouldn't. This is like complaining about the Corvettes harsh ride - it's NOT a defect, it's part of the design and an integral part of giving sports car enthusiest the performance they want at a reasonable price. Nobody is forcing anybody to settle for the harsh ride of the Corvette, nor is anybody going to force you to to purchase the 50 1.2L.
Nobody's forcing you to buy the 50 1.2L, but Canon isn't admitting to the focus shift issue either. Also many of the "reviews" out there completely don't mention this issue at all leaving customers to purchase it and find out themselves. I really have to wonder about some of those review sites. The focus shift is easily demonstrated and reproduced. Yet not one has commented on this, only discussions in forums like this mention the problem.
Additionally, the 85 1.2L has no such issue. I'm aware of the design trade-offs but I think Canon really didn't get this one right. I'd have much less issue with this lens if Canon were upfront about what it does and doesn't do. Canon hasn't responded at all to any of the issues brought to them months ago. A statement by them and a tech note on their website on the lens are all that are what is really needed.
rceres wrote:
I think pretty clearl that the lens is going to focus shift at at close distances at f2.8, just like other lenses exhibit barrel distortion or flare or chromatic aberation, or.... The fact that a lens exhibits certain optical defect doesn't mean it doesn't "work right", it means it works to it's optical design.
The issue is clear now that the lens has been out and this has been discussed extensively. Current buyers benefit from this. I don't expect Canon to detail all the quirks of their lenses upon release but I was definitely not expecting something like this from a $1600 lens. It was my fault for purchasing the lens last December before there was much discussion on the performance. Live and learn.
I agree with a lot of what you say. I got the lens for low light shots and that is where I use it most. However, I'll use it the full range including in the problem region. I'm not going to go and get another lens to use at f/2.8 just because of the focus shifts. Luckily the outer AF points correct for the shift to a large part.
rceres wrote:
With good techniq manual focus can be quite quick most of the time. The big advantage of manual focus, however, is the ability to use the photographer's big brain rather than the camera's much smaller brain. Most photographers, after all, are much smarter than their camera.
You honestly reckon you can focus as accurately and as fast as AF in all scenarios?
The point of my thread was to alert others to my experience and to recommend they have a good return policy, if they decide, like me, to try the lens.
Your lens works fine? Great. So did the MK III for people who don't use AI servo.
No one is forcing me to buy the 50mm f/1.2. Correct. I'm glad that I was able to RETURN it. The first lens I have ever returned. Ever. I am not a pixel peeper, and all my lenses work well at all focal lengths and apertures.
The 85mm f/1.2 does not have this issue. The 50mm f/1.0 does not have this issue. My 200mm f/1.8 does not have this problem. All fast lenses, complicated lenses. They can design a 50mm f/1.2 that works properly at all apertures.
The B&H salesperson took back the lens and I told him about the focus shift. He got tight lipped and refused to talk about it. Well I'm going to make a stink until Canon does something about it.
Canon's professional "L" line is aimed at professionals. Well I am a working professional and I expect the AF to work properly in a lens I paid $1400 for.
I don't want a lens that produces mush at F2.8 and under. That's why I sold my 50mm F1.4 and bought the 50L. Not my favorite FL on FF but a least one reviewer considers it the best at the big apertures. If you routinely shoot at F2.8 and above get the F1.8.
