Canon T4i/Sigma 35mmART issues

Some may remember my recent thread detailing me experiences with the Sigma 35ART.
(in short... inconsistent focusing on 3 out of 5 shots)

Anyway.. I tried another copy yesterday and I demonstrated these issues to the shop staff.

On their suggestion, I tried the lens on their newer T5i.. and interestingly it was more consistent. All shots were in focus.

I'm going to see if there is any possible body calibration that I could have done. (and if it's worth it for a 300$ body)

I wonder if anyone has had experiences like this...

Either way.. I guess the 35ART is my choice.. and I guess a new body is in my future too.

Dan Kearley wrote in post #17292634
Some may remember my recent thread detailing me experiences with the Sigma 35ART.
(in short... inconsistent focusing on 3 out of 5 shots)

When I look at your previous thread I was under the impression you got a good copy (see comment #33 of prior thread). Now it seems you are still in a trial and error mode. Have you tweaked any of these lenses with a dock?

Sorry; no.. I haven't bought a lens yet. All testing has been in the shop, so no usb dock.

I'm mainly intrigued by the idea that my body might be related to these focusing issues.
(well.. at least the newer T5i body was doing a better job)

maybe check for firmware updates for the body?

I did drop the camera 2 years ago... so it went to Canon for repair.

Who knows.. maybe at 1.4, it exposes some issues I didn't know about.

Dan Kearley wrote in post #17292689
Sorry; no.. I haven't bought a lens yet. All testing has been in the shop, so no usb dock.

How is the lighting level in the shop and the contrast on the subject matter? These can be issues in focusing.

Average shop lighting... white text on black surface. I should upload the photos, shouldn't I?

I wanted to add an update here.

I just bought a 5D3.. and I'm amazed with how the 35mm focuses. Same lens on the new body... it's SO much more accurate. I'm thrilled.

My old Sigma 30mm 1.4 was quite problematic.. I would get 1 sharp shot out of every 3. Throw a ND filter on and you get NO good shots.
The 35mm was much better... but now on the new 5D3, I'm amazed. Even with the ND on..

It's possible my T4 body has some small issues that don't get noticed otherwise?