Front focus issues with my 5DC

Last week I bought a used 5DC and everything is great besides the AF.
Only with 50mm 1.8 it doesnt focus correctly, it always focus closer than I want it to, since there is no focus adjustment at this model is there anything I can do about it?

At which apertures does this problem occur? And do you use focus & recompose?

F1.8-F2.8 and no I dont.

Please post some pictures with exif attached so that we can better analyze the problem.

Do you also have this problem when you use the center AF point?

Try different focus modes as well. Keep us posted on what you find out.

You may have to send your camera and lens to a Canon Service Center so that they can zero them out together (calibrate camera body AF then adjust lens to match). I did this with my 5D and 70-200 when I found it was front-focusing with all lenses (body issue), and focal plane varied by focal length (70-200 issue).

My 5D/50 1.8 combo works a lot better if I use the focus-assist beam from flash unit. You can the flash to NOT fire, just using the red beam to focus. Works for me.

If it's front focusing consistently and only with one lens, you could sent in the lens. However, with the 50mm f/1.8 the service cost would probably be more than the cost of the lens. If several or all your lenses are front focusing, then the body has to go in for calibration. As you pointed out, this body is not MFA capable.

I use only the center AF point, I had some pictures that you could see the problem immediately but I cant find them..
I focused on his eyes and mouth

I know the nifty nifty has a really crappy minimum focus distance. How close we're you? Does this happen no matter what the subject distance is?

I wasnt that close that it is closer than its minimum focus distance, these pictures are cropped. I didnt have this problem with my 500D by the way.

First, do you have a filter on the lens? Filters can mess with AF. Remove any filter from a lens before doing any focus testing.

Second, if the problem only occurs with the one lens, other lenses seem fine, it's most likely the lens and not the camera. (If your other lenses are correctly and accurately focusing, adjusting the camera to focus correctly with this particular lens would make it incorrect with all the others.)

The 50/1.8 in particaly is known to have pretty sketchy AF (slow and erratic to the point it's often not possible to accurately Micro Adjust it on cameras that have the feature).

At f1.8, depth of field is really shallow, especially as close as your examples appear to be shot. Even minor focus accuracy errors can turn into a big problem at f1.8.

It looks as if you're running your tests under artificial/household lighting. That can cause focus problems, too... especially any form of fluorescent lighting (CFLs, for example). Try doing your tests under better lighting, such as outdoors. Yes, it can help to have Focus Assist, which is possible on 5DC only with an accessory flash providing it or with an ST-E2 or E3 module.

AFAIK, 5DC doesn't have Live View and the 50/1.8 lens doesn't have a focus scale, so some of the common focus-checking methods and assists aren't possible. It might help to have an angle finder or other magnifier on the viewfinder, tho.

Be sure you are using One Shot focus mode. AI Servo just isn't as accurate. (And AI Focus isn't really a focus mode at all.)

You might want to download and print out a focus test target, use that instead. Oddly shaped and furry subjects can fool the AF system.

Your examples do look front focused, but the EXIF also shows them shot at 1/50 (and f1.8, ISO 800). Might be better to bump up the ISO (noise isn't a concern for these tests, and the 5DC should be able to shoot 3200 pretty cleanly anyway). Hopefully you are using a tripod, anyway.

The minimum focus distance of the 50/1.8 II is 1.5 feet... not really all that bad. But at the MFD (18 inches) and f1.8 aperture, the totaly depth of field is about 1/3 of an inch.

About the only thing you can do yourself is clean the lens-to-camera contacts, both on the lens and just inside the mount on the camera. I'd suggest carefully wiping them with a cloth lightly dampened with a few drops of isopropyl (rubbing) alcohol. Take care to keep off the camera's mirror and the lens' optics, of course.

5D classic was introduced in 2005, replaced by the 5DII in late 2008... so a used one is bound to be 4 or more years old. Wouldn't be surprised if it needed a checkup, cleaning and adjustments. Back in the days of film and mechanical cameras, we had them tuned up and calibrated every year or two, simply as a matter of course. Today's electronically controlled cameras are more precisely calibrated to start with and seem to hold their settings longer, but likely still need an occasional tune-up. It wouldn't hurt to have it checked out.

I don't know if the "mirror fix" issue with the 5DC can effect AF in any way or not. Has it been done on your camera?

amfoto1 wrote in post #15623263
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Your examples do look front focused, but the EXIF also shows them shot at 1/50 (and f1.8, ISO 800). Might be better to bump up the ISO (noise isn't a concern for these tests, and the 5DC should be able to shoot 3200 pretty cleanly anyway).

One other thing to note as well is that focus checks should be done under optimal lighting conditions. The 5Dc's AF system is quite old and not really well suited for low light AF. Bright diffused daylight works great for AF testing.

^^ If you are testing you have to give the equipment a chance. The AF system needs contrast to latch on to and you should be aware that the points actually extend beyond the boundary of the red boxes. A tripod should also be used if you want to be certain you are getting correct results that are not skewed by your body swaying.