Backfocusing? Need second opinion!

Alex, it looks to me like your camera's backfocus is practically negligible (not to the eye, obviously, but it may mean that your camera is within spec).

Have you taken regular shots and observed such anomalies?

Tiger,
thanks for the response... sorry it took me a bit longer than usual to respond to you.

Well, the back focusing is one of the issues (at least, as you pointed out, "perceived back focusing) but I'm very concern about the just arrived 24-70mm at its ability (or lack thereof) to perform the way I would expect from a lens costing so much.

I was concern about the fact that with wide aperture and short focal lengths...the lens is not sharp at all, as you can see.... you cannot even read where it says "Focus here" on the black line....

I will move the same concern on a new thread since it seems this one has lost its "readers' appeal"

Regular shots ? well no... I have not, and I intend to do that tomorrow... and will see what the results are. The lens (24-70mm) at 70mm is right on and as sharp as you can get ..

Thanks once again...


Alex

tigerotor77w wrote in post #6888105
Ooops. Wrong thread.

My battery tests were such that one of the front batteries was in focus, not the one I "focused" on.

Okay. I'll send in the two "uncalibrated" lenses to Canon, then -- no need to send in the calibrated one, right?

Do I need to send in any examples of photos, or is "lens front-focuses" enough?

Edit:
I just realized that I didn't post my images in this thread, and that my battery tests that I referred to weren't even here. Can you take a look at https://photography-on-the.net/forum/showthre​ad.php?t=614280 and let me know what you think?

No, just the ones your concerned about.

I didn't need to send in examples for my back focus issue, but you can ask them when you speak to them, just in case.

There does seem to be some from focus issue from your battery test (assuming your middle batteries were at the same distance from the camera and the duracells were equal distance behind and in front.

Alejoviade wrote in post #6891429
Well, the back focusing is one of the issues (at least, as you pointed out, "perceived back focusing) but I'm very concern about the just arrived 24-70mm at its ability (or lack thereof) to perform the way I would expect from a lens costing so much.

I was concern about the fact that with wide aperture and short focal lengths...the lens is not sharp at all, as you can see.... you cannot even read where it says "Focus here" on the black line....

What AF mode and point did you choose? If the center point was *selected* by you manually, then I'm not sure what to suggest (perhaps someone with more experience can chime in). If you didn't select a focus point, it is possible that the camera didn't choose the one that you would have wanted it to choose.

curiousgeorge wrote in post #6897810
There does seem to be some from focus issue from your battery test (assuming your middle batteries were at the same distance from the camera and the duracells were equal distance behind and in front.

*IF* there is a FF issue, can you tell from these shots that it's the lens and not the body? With the [academic] semester about to end, I won't have access to another XSi for about a month -- well-beyond my return time.

In the meantime, though, I think I should probably try to go out and shoot a bunch of photos and see how they turn out. I have a hypothesis for what I'll find, but without another body to use, I don't know what'll happen even if I do end up sending everything to Canon for calibration. Is there any such "calibration" for the body [or is it all for lenses]?

tigerotor77w wrote in post #6897872
Is there any such "calibration" for the body [or is it all for lenses]?

I'd like to know this too. Since I plan on sending the 85mm to them soon.

You can send the body in with the lens to have them calibrate the lens to the body.

My 100mm exihibits the same backfocus issue on my 1Ds, so either the body is messed up or the AF point is misaligned with the center point.

tigerotor77w wrote in post #6897872
What AF mode and point did you choose? If the center point was *selected* by you manually, then I'm not sure what to suggest (perhaps someone with more experience can chime in). If you didn't select a focus point, it is possible that the camera didn't choose the one that you would have wanted it to choose.

*IF* there is a FF issue, can you tell from these shots that it's the lens and not the body? With the [academic] semester about to end, I won't have access to another XSi for about a month -- well-beyond my return time.

In the meantime, though, I think I should probably try to go out and shoot a bunch of photos and see how they turn out. I have a hypothesis for what I'll find, but without another body to use, I don't know what'll happen even if I do end up sending everything to Canon for calibration. Is there any such "calibration" for the body [or is it all for lenses]?

No you can't tell. That's why you should send both in. Unless you need it for any critical shoots, just wait will you can be without your body for a week or so.

ef2 -- I was told that the lenses (or body) aren't calibrated to "each other" as much as they're calibrated "to factory specs." (My question was whether I should send in all my lenses or just the ones I suspect to have a problem.)

Hate to resurrect a thread. But, I used this lenses the other day.

This shot

http://i723.photobucke​t.com …232/3designforu​m/sis8.jpg

I had to manual focus it. It would not focus properly on AF. I had not seen any backfocusing problems prior to this on my XT. But, this time, AF just wouldn't work at all. Her face was blurry in every shot. Using tripod as well.