Here are some crops of the 50L/1.2 wide open. These were shot with a 5Dclassic using Manual Focus. As you can see CA really plays a role when using this lens wide open on contrasty subjects. If focus is even just very slightly off, you will notice it rightaway. But when it's focused well, this lens is very sharp wide open.
Images were imported into LR4.1, cropped to 1000x1000 pixels and exported using standard sharpening.
This means that these are 100% crops.
I have lived the era of MF from 1986 (when I started SLR photography using a Minolta X-700) until 1998, when I bought my first AF camera (Nikon f801s). From the old days I'm used to the split focusing screens, but with my 5Dclassic + Ee-S I need to focus without it. 5Dclassic AF lets me down only when used with the 50L, but focusing manually with the Ee-S focusing screen is very very accurate.
Problem
The only downside is that I need about 2-4 seconds to focus manually. What I do is turn the focusing ring back and forth from front to back focus and then turn it towards the focal point until I see it sharp manually. Sometimes I see sparkles when it's in perfect focus, but not mostly, especially when it's dark.
So is this the best approach and is this just about practice? Or do you have any advice my MF could benefit from?
I guess you've proven you need to use the autofocus microadjustment feature on this body that it doesn't have.
Other than that, you're doing it right for hand-held.
On a tripod, I used to use my Olympus angle finder from the OM system with my 5D. The Canon ones for EOS are very hard to find, but ones from old manual systems should be easy to find, often in excellent condition. I know the OM ones fit but I've seen reports the Minolta MD and Pentax ones do too.
With my 50L I use the AF to get it close, then fine tune manually.
How close where you to each subject? I found my 50L to AF much worse at closer distances on my 5D's.
@Melcat: Thanks for your input about the angle finder. I'll look into that for when I use a tripod. However I rarely use one, because I'm into event and wedding work. About the focus inaccuracy: I disagree that I've proven that this is a MA issue. Have a look at the last three images. Two AF images, but very different focus. Additionally: when pointing at a LensAlign, and taking time to carefully focus, 5D on a tripod, their was almost no need for MA.
@Jason: I tried a variety of focusing distances. The tripod pin was very close, obviously, but the first image was about 4-5 metres away. The focus inaccuracy is there at all distances. At longer distances DoF is larger so I don't notice it as much, but at f/1.2 it's hard to get a good image.
Other than that, you're doing it right for hand-held
Well the images are all sharp, but i'm too slow at this. Anyone got ideas to speed up the MF?
How does it do outdoors in fairly decent light and contrast with the 5D1
I'm evaluating the exact same setup. 50L borrowed from CPS on a 5d1 and 1Ds2.
The 5D1 does pretty good when there is a decent amount of contrast and not under marginal kelvin temps away from daylight.
rabbitmountain wrote:
About the focus inaccuracy: I disagree that I've proven that this is a MA issue. Have a look at the last three images. Two AF images, but very different focus.
Yes. There's a precision problem, which means you don't get the same answer all the time. The other images suggest there's also an accuracy problem, which means it's the wrong answer. It's possible to have one, the other, or both. AF microadjustment, if you had it, would fix accuracy but not precision. But if you could make it more accurate the imprecision might not matter.
when pointing at a LensAlign, and taking time to carefully focus, 5D on a tripod, their was almost no need for MA.
I too found with this body and lens on a tripod that autofocus and manual focus delivered the same correct result. I know there's variation in bodies so was unwilling to say yours should be the same. But, given it is, you have to start thinking about things like body sway and movement from mirror slap. There's no way out - if it works on a tripod, but not handheld, it must be something to do with the camera being handheld.
Melcat,
I dare think there is a way out. And I think it has to do with the contrast of the subject being focused on. A LensAlign target is full of contrast. So it's easy even for a 5DmkI to focus with precision, as you put it. But things get funky when focusing on less contrasty subjects in low, artificial light. Unfortunately, in my line of business this is the type of shooting I normally do. In these circumstances there isn't much precision, though there is with the LensAlign target.
I didn't try to focus on the Lens Align target with low light though. And I don't own the lens yet, so I can't do any more tests now.
Here are some 5DmkII 50L samples, same day, same 50L. All AF. The 5dmkII is undeniably better than the 5Dclassic. But there still are some strange misses.
Well this is all but a scientific test. I just shot away like I would during a real gig. Seemed the most appropriate thing to do.
Still I was aware of the thin DoF of the 50L @f/1.2, so I made sure I didn't move and I disabled back button focus to minimise the lag between AF and exposure. I put one foot in front and held the camera tightly.
But yes, even through the viewfinder I noticed that multiple AF on the same subject yielded different focusing distances. Even with the 5DIII sometimes, but much much less so.
Sorry to go slightly off topic but I'm thinking about getting this lens with the 5D2 and use MF with a focusing screen. My question is in regards to the focusing screen. I notice that they usually have a clear circle in the middle surrounded by matte glass.
Doesn't that mean you can only focus in the middle of the frame? What if you want to focus off center? Do you have to focus and recompose? That would make it hard to get accurate focus with a really thin DOF on wide aperture like f/1.2 no?
