EF 50mm f/1.4 on FF vs. APSC?

I have a 50 1.4 that works well on my 6D; f/1.4 is quite useable. It has never been good on the 60D. I have to go to f/2.8 to get reasonable sharpness. I picked up a used 7D recently and the 50 1.4 acts the same way on the 7D as it does on the 60D. I have to be at f/2.8 or smaller for decent sharpness. I don't need MFA (for any lens) on the 6D. Just wondering, is the 50 1.4 a bad actor on APSC?

Your question is phrased in such a way that it seems you do not understand something quite basic...

In terms of overall IQ, any lens performs the same on APS-C as it does on a FF camera...it merely captures a SMALLER AREA (about 15x22.5mm) than FF (24x36mm)
If anything, the need to magnify the smaller captured image to fill the same final size print (e.g. 16x24") makes any lens shortcomings that much more apparent...the only spec which might be masked by smaller area is the % vignetting at the edges of the smaller frame area.

Have you checked the lens for front/back focus on the 60D? The fact that the lens does not require MFA on the 6D does not mean that it doesn't need it for the 60D. It could be that the camera body (60D) is off...

Shoot a ruler at an angle. If you find a sharp focused area, then it needs MFA. If it is soft throughout, then it is likely the magnification of the crop.

Perhaps. But I don't see the huge difference with any other lens. 28 1.8, 17-40, 35 IS, 100 2, 70-200 f/4 IS, 100-400L all look a small bit better on FF than APSC. The difference in the 50 1.4 is HUGE. It is completely unusable until f/2.8 on both crop cameras. I shoot all my other glass wide open on both formats with no issues.

MakisM1 wrote in post #17515325
Have you checked the lens for front/back focus on the 60D? The fact that the lens does not require MFA on the 6D does not mean that it doesn't need it for the 60D. It could be that the camera body (60D) is off...

Shoot a ruler at an angle. If you find a sharp focused area, then it needs MFA. If it is soft throughout, then it is likely the magnification of the crop.

Good idea, Gerry. I could try MFA on the 7D. 60D doesn't have it.

photozone.de characterizes the 50 f/1.4 as having high vignetting, at -2.7EV on FF. MTF values are quite good at 3557 line-pairs/picture height...a bit higher than the lauded 70-200mm f/2.8L IS II zoom!
It says about MTF,

"The resolution chart shows a rather wide spread in image quality across the tested aperture range but this is typical for most ultra-large aperture lenses. The center performance is very good at f/1.4 but the borders are just on a good level and the corners are soft. The contrast level is also somewhat reduced especially towards the corners. The situation improves quite a bit when stopping down to f/2 - the center is lifted into excellent level here and the corners start to get acceptable. There's a further boost of the border/corner quality at f/2.8 - the outer region reaches very good figures here (albeit just). "

It summarizes,

"It is no surprise that the Canon EF 50mm f/1.4 USM is a very popular choice among Canon users when it comes to choosing a standard lens. It offers probably the best compromise between quality and price here. That said it's not a flawless lens when used on a full format DSLR. The contrast level is quite a bit reduced at f/1.4 and the corners are soft here. However, the results are good at f/2 and nothing short of great at medium aperture settings. Unfortunately there's an extreme amount of light falloff at max. aperture and it takes two f-stops to reduce the problem to a more or less negligible degree. Lateral CAs are nothing to worry about. The bokeh is generally good but not outstanding. Typical for such lenses there's quite a bit of bokeh fringing (LoCAs) at large apertures. "

As I stated earlier, the vigetting measured by photozone.de on APS-C falls to -0.98EV on an APS-C camera.
As for MTF, photozone.de says,

"The resolution characteristic of the Canon lens is somewhat mixed. The image center is already very good at f/1.4 but the borders are quite soft. This is a difference compared to our initial test and possibly the result of a slight centering issue that we've seen in the tested sample. The overall contrast is also rather mediocre at this setting. The situation changes when stopping down to f/2 already. The border quality is lifted to good levels and the overall contrast improves as well. The quality reaches quite breathtaking levels from f/2.8 to f/8. It's quite safe to assume that the lens outperforms the 15mp sensor of the base DSLR here."

And it summarizes,

"The Canon EF 50mm f/1.4 USM is a rather obvious choice when looking for a standard lens to be used on an Canon APS-C DSLR. That said it struggles a bit at maximum aperture - the borders are somewhat soft here, the contrast level is reduced and the amount of vignetting could be better. However, the image quality is already quite impressive at f/2 and nothing short of outstanding in the f/2.8 to f/8 range. Lateral CAs are nothing to worry about. The bokeh is generally very good (within the APS-C scope it avoids some of the problems that we've seen in the corresponding full format test) but typical for such lenses there's quite a bit of bokeh fringing (LoCAs) at large apertures. "

GeoKras1989 wrote in post #17515329
Good idea, Gerry. I could try MFA on the 7D. 60D doesn't have it.

Yes! But of course you cannot do anything if it is the 60D body that is at fault...

Look for a focus plane at f1.4. (Shoot a ruler). It may not be where you expect it to be...

EDIT: This was posted with my post #1 in POTN. 'Am I doing this right?' For my 60D/EFS 18-200...

Got it. I just find it weird that it doesn't work, and to the same degree, on two different models of APSC cameras. I just don't use it on the 60D. When I got the 7D, I thought well maybe.... I will try MFA and see what happens.

George, do you have portions of the frames of shots made with the APS-C images which illustrate your complaint, "It has never been good on the 60D. I have to go to f/2.8... the 50 1.4 acts the same way on the 7D as it does on the 60D"?

What shutter speed used?...do you know that the minimum speed rule of thumb for APS-C is 1/(FL/1.6) whereas the 1/FL is for FF?!

Wilt wrote in post #17515408
George, do you have portions of the frames of shots made with the APS-C images which illustrate your complaint, "It has never been good on the 60D. I have to go to f/2.8... the 50 1.4 acts the same way on the 7D as it does on the 60D"?

No. I can do more controlled work this evening.

I noticed it shooting existing light, indoors, at night. I thought the fluorescent light may be the problem, so I switched to flash. Even with the focus-assist beam from a 580EX II, both the 60D and 7D were just crap wide open. I didn't even have to upload to computer; they looked terrible on the rear LCD. I have used that lens on the 6D with no issues. Sure it is better, over more of the frame, at f/2. But it is quite good wide open on the 6D. It is unusable on the crops at f/1.4. Noticeably better at f/2, but still not good. It is better at f/1.4 on the 6D than at 2.8 on either crop. That is pretty bad.

I think all glass is better on ff than apsc. This may be an MFA issue, but I think it odd that both apsc bodies look bad, to about the same degree. I will try to MFA the lens on the 7D tonight. If that fixes it, I may keep the 7D and sell the 60D. I was going to go the other way around.

I like my EF 50/1.4 much better on APS-C than on FF.

But that's because it behaves as a more interesting short tele on APS-C, while it's just a "boring standard lens" on FF.

I actually don't see much difference in IQ, that isn't there with any other lens too. FF simply has higher resolution and uses weaker AA filter than the croppers.

I generally set my 50/1.4 to minimum f2.0 by default, for sharper shots. My copy is a little soft, but IMO is usable wide open. There seems to be some variation in this... or maybe it's just differences in what we each find acceptable.

MFA might help.

If using a "protection" filter, might try it without that, too.

Before you try MFA, try using Liveview Contrast Detection AF, or 10x Liveview manual focus to see if that gets you sharper images.

Alan, Mike, both good suggestions. I should have time for all of this next weekend.

I got home today and could not resist. 60D in LV nails focus everytime, at any distance, PDAF not so much. DOF covers the error at 12'+ or so. 7D is much better than I thought. Last night I was shooting f/1.4 at 6-8 feet. Much of my issues may have been DOF on the 7D. Will try MFA this weekend. The 7D in LV and center-point point AF are very close. Well, at least I know it is only the 60D. Was planning to keep the 60D and sell the 7D. Now I'm not sure.

Sorry to hear this. Unfortunately, this is the Achilles heel of the 60D. No MFA. At this stage I don't think it is worth trying to have the 60D calibrated. It will work fine in MF and with the EFS lenses.