Canon 50/1.4 focusing

[jrista]

I'm happy with my 50mm f1.4, but the DOF is pretty shallow when used close up at f1.4. Have you tried manual focusing, on a tripod to see if it's any sharper? I'm wondering if the lens is actually soft, of if the softness is being caused by something else.

Wide open the 50/1.4 still has uncorrected spherical aberration. From a portraiture standpoint, thats actually a desirable trait, as it doesn't expose in full detail every blemish. Granted, there is software that can "fix" that in a click these days, but generally speaking, a little spherical aberration in a portrait lens is useful. Spherical aberration (and the small amount of CA that is present) contributes to the less than perfect sharpness of the 50/1.4 at wider apertures. You would need at least f/2.8 to really start seeing good sharpness, and f/4 to approach the lenses maximum resolution.

Expecting perfection wide open on a fast lens...well, its like expecting world governments to stop spending and reduce debt...highly unlikely.

[nightbreath]

I'm having the same issues with softness and focusing wide open. I find this lens reliable only when stopped down to f/2.8, all brighter apertures can lead to missed / blurry shots.

[dbduchene]

I picked up a 85 f 1.2 and played with it this weekend on my 7D this weekend a little taking flower shoots in a few spare mintues that I had. I truly love the lens. I also picked up a sigma 50 f1.4 and will have to try and find time to go shoot it a little. THe sigma is to hold me over till I find a good deal on the canon 50 F 1.2 took s few test pics the day I got it and then in the case. I have a shoot coming uf this summer that I will need it on for several days if I do not pick up the canon. Both of those lenses will be on my 5Ds for the day or 2.  THe 50 1.2 worked just as expected not fast but focused using the point that I told it to where I was holding that point. That said it is not something to be expecting to focus fast.

[marekjoz]

What I foundwith such fast lens like 50 1.4 was, that it's very easy to recompose a focus, which I blamed at start as AF error. I think a lot photographers use this technique when holding camera in hands and shooting spontaneously. Total DOF for 7d is like 19cm on subject 3 meters away (at shorter distances it's even less). DOF is relative - in area of 19cm subjects are considered to be  sharp, but you find more and less sharp areas within this range. If you block AF by pressing shutter half having focus on ie central AF point and after that you recompose your frame, you have a chance to fall out of focus. I've never found 50 1.4 to misfocus neither on 7d nor 5d2, assuming of course there was light enough.
Missed shots happen to me in real situations at low light or recomposing but never with good light or on tripod.

[Autocall]

here is an extract of the best review of this lens in my op.
hope it helps
Although it is soft wide open, the Canon EF 50mm f/1.4 USM Lens is sharp at f/2 and very sharp when stopped down to f/2.8 or narrower. Corners are soft until f/2 for 1.6x FOVCF bodies and f/2.8 on full frame bodies. Strong halation is present at f/1.4 (a soft, dreamy look) with some CA (Chromatic Aberration). Colors and contrast (after the halation diminishes at f/2 or so) are very nice. The 50 f/1.4's 8-blade aperture creates a good foreground/background blur quality. Light fall-off is noticeable through f/2 on a Full Frame body, When mounted on a 1.6x FOVCF body, light fall-off is noticeable only through f/1.6 or so. My exposures with this lens run about 1/3 stop brighter than with most of my other lenses.  

from
http://www.the-digital-picture.com/Reviews/Canon-EF-50mm-f-1.4-USM-Lens-Review.aspx