5dMK2 focus microadjust

timplog

moved from the 5d to 5dMK2 and wonder how many of you MK2 users are having/wanting/needing to "microadjust" the focus for any of your lenses?? Curious just how frequently this function is being used-and should I be obsessing (!) without cause..Thanks




Canon 5dMK2
24-70L 2.8, 70-200L IS 2.8, 100-400L IS
580EX, 1.4 TC, Bogen, Wimberley

ziggy53

I haven't had to with:

EF 50mm, f1.4 USM
EF 135mm, f2L USM
EF 28-80mm, f2.8-f4L USM
EF 70-200mm, f2.8L USM

I haven't tested a few additional lenses yet but the above are fine without any micro-focus correction.

kdog

That's my experience as well. I spent an afternoon going through all my lenses using a commercial alignment jig (LensAlign Pro). It's a fair amount of work to do it right and make sure everything is precisely aligned. At the end of the day, I had changed nothing.

Scott_Quier

My experience is just the opposite. I spent the better part of 3 or 4 hours and found that only one of my lenses (EF 85 f/1.8) did not need at least a little adjustment. None of them were out by more than about 5 or 6 "adjustment units".

Cameron

Scott_Quier wrote:

My experience is just the opposite. I spent the better part of 3 or 4 hours and found that only one of my lenses (EF 85 f/1.8) did not need at least a little adjustment. None of them were out by more than about 5 or 6 "adjustment units".

Interesting - all of my lenses were fine without adjustment EXCEPT my 85 f/1.8 which needed +5.

timplog

Scott_Quier wrote:

My experience is just the opposite. I spent the better part of 3 or 4 hours and found that only one of my lenses (EF 85 f/1.8) did not need at least a little adjustment. None of them were out by more than about 5 or 6 "adjustment units".

Thanks Scott-looked at your link /postings AF Microadjusting and found great info and conversation-thanks for your time and effort! Wonder does one just launch into this microadjustment business "in case" ones lenses might be off or....is it user technique to blame-which comes first?? Thanks again

timplog

ziggy53 wrote:

I haven't had to with:

EF 50mm, f1.4 USM
EF 135mm, f2L USM
EF 28-80mm, f2.8-f4L USM
EF 70-200mm, f2.8L USM

I haven't tested a few additional lenses yet but the above are fine without any micro-focus correction.

Thanks one and all for most helpful comments-just love this forum/participants-

craig_d

I am interested in doing focus accuracy tests on my lenses but I haven't found any real need to do so because my pictures generally come out well enough without it. It's conceivable that my shots might be even sharper if I tested and correctly adjusted my lenses, but I haven't gotten around to it.

One concern I have is that there are instructions online for a number of variations of focus accuracy testing involving different charts or other tools. Most of these I simply do not trust because I can see flaws in their design. For example, anything that involves focusing on a surface that is curved or oriented diagonally to the lens axis cannot be relied upon because you don't know exactly what point your camera's AF system is actually focusing on. A more sensible approach is to focus on a flat surface that is perfectly perpendicular to the lens axis, and have something else nearby that is set up diagonally so that you can see the effect of front- or back-focusing. The problem then is how to ensure perfect perpendicularity. The LensAlign Pro Focus Calibration System seems to be a good solution, but it costs more than I really want to spend for such a thing.

Another question is how meaningful this sort of focus testing is when you consider that cameras are not guaranteed to focus in exactly the same spot each time you focus them, even if the subject is a test chart that is oriented perpendicularly to the lens axis. Haven't we all had the experience of half-pressing the shutter button to focus the lens, then releasing it and half-pressing it again, and feeling the lens slightly adjust itself again? Even when tripod-mounted? Doesn't this suggest that all this testing and careful micro-adjusting may be exceeding our cameras' limits of repeatability and therefore basically be a waste of time except in the most extreme cases?

Scott_Quier

timplog wrote:

Thanks Scott-looked at your link /postings AF Microadjusting and found great info and conversation-thanks for your time and effort! Wonder does one just launch into this microadjustment business "in case" ones lenses might be off or....is it user technique to blame-which comes first?? Thanks again

My take on it is that the lenses and cameras we use are built to tolerance specifications. If both the lens and camera are off in the same direction, there is a strong chance that the effect will be noticed in the photos. So, to rule out equipment (take one unknown out of the equation), I spend the time necessary to get it as close to spot on as I can. Then I can safely say that any problems in the images are pilot error.

davev

I should take the time to do this, but as it is, I've just been doing it as I go along.

I've noticed that the lenses I have done, all are off 2-5 places. I needed to move the
focus plain farther away.
Lenses were: 24-105, 100-400, 300 f2.8 (with and without a 2X tc), 70-300, 28-105.
It didn't care if they were L lenses, or consumer lenses.
All this says to me is that the lenses are probably closer to tolerance than the camera.