New toy, EF 100 Macro - Problem with manual focus

[Jesper]

I got my newest toy today, the Canon EF 100mm f/2.8 Macro USM (http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=194451&is=GREY ) with the hood ET-67 (http://www.bhphotovideo.com/bnh/controller/home?O=details_accessories&A=details&Q=&sku=194452 &is=REG). I ordered it from B&H and although I had to pay import duty (6.7%) and VAT (19%) it was still about € 25 cheaper than the German Internet shops I looked at.

I made some test photos with it on my 10D (on a tripod, with mirror lock-up and timer release). I used manual focussing and noticed something I had already suspected with my other lenses. The focus on the photo is in front of the focus I see in the viewfinder. In macro photos, with a very shallow depth of field, it's clearly visible.

So this is NOT one of those famous 10D front or back focussing issues. It happens with MANUAL focus.

Could this be because the diopter setting on my 10D is not right, or is there something else out of line which I need to go to a Canon service center for?

[kawter2]

if you are using manual focue.. have you checked your diopter?

[Adam Hicks]

Good point Kawter... especially in manual focus on a macro, what you see in focus could be different from what the lens sees. There's not much else it could be.

The 100mm f2.8 Macro is a fantastic lens. Good size, great macros and a really nice bokeh when used as a prime tele. I need to order the lens hood myself... haven't had any issues with lens flare or reflections yet though.

[Sendide]

I agree woth the previous reply, since it a manual focus issue that does not appear on AF, it can only come from what ''you'' juge on focus, since the DOF is harder to control on Macro photography, focusing issues become more pronouced.
use a tripod and focus manually on a fixed subject, ask a friend to do the same thing and check out both picutres, if both come out out of focus on the subject then :shock: :shock: :shock: :shock:
I have the same lens and do a lot of macrophotography, I LOVE THIS LENS
regards
Khalid

[DAMphyne]

I thought the focus problem with the 10D was a sensor placement problem.
If that's the case, wouldn't both, manual focus and auto focus have the problem?
How do you manual focus these things anyway? They don't have a finder on the viewfinder screen. If it's just by "eye" I need a lot of help.
I wish Canon would find a way to install a split-image finder in my 10D.
That is the one thing I really miss about my film camera. I'd give all my film stuff for a XK or a XE7 with a couple of lenses.
Oh well, excuse my rant.

[Jesper]

if you are using manual focue.. have you checked your diopter?

....That's what I was asking in my post above: :roll:

Could this be because the diopter setting on my 10D is not right, or is there something else out of line which I need to go to a Canon service center for?

I don't know exactly how the diopter setting works. My own eyes are quite sharp (don't need spectacles) and I do the manual focussing by eye. Because the lens is f/2.8 and the DOF is very shallow, it's actually not that hard to see where exactly the focus is.

But what I wanted to know is, if this problem could be caused because the diopter setting is wrong, before I spend time and effort to experiment with different diopter settings? Or can't this be the diopter setting and does it mean that my mirror or something else isn't properly aligned?

[nosquare2003]

But what I wanted to know is, if this problem could be caused because the diopter setting is wrong, before I spend time and effort to experiment with different diopter settings? Or can't this be the diopter setting and does it mean that my mirror or something else isn't properly aligned?

Diopter setting is one good guess. Has it been adjusted (+ or -)? I once lent my camera to someone and he adjusted the diopter (accidentally). And I thought that there was something wrong with the autofocus...

BTW, I have never experience the sensor placement error...

[Jesper]

OK..... I will do some testing with different diopter settings tonight when I get home. Unfortunately it's hard to see when the diopter adjustment wheel is in the "0" position on the 10D. I hope that solves the problem....

The EF 100 f/2.8 is a very nice lens! I already noticed, in the parts that are in focus on my photos, that it is VERY sharp, it seems even sharper than the EF 50 f/1.8 II.

[Jon]

If the diopter setting is off, the AF index points will show up as fuzzy in the viewfinder. Adjust so those are crisp and you'll be properly focussed on the screen. If the image on the focussing screen does appear to be sharp with your current diopter adjustment, then that's not the problem. When you focus on the focussing screen, the lens projects a back-projected image onto it. You, and the viewfinder/diopter adjustment are viewing that projected image, not looking through the lens as you would with a pair of binoculars, in manually focussing. That's one reason why, for critical, and macro/micro, work focussing screens with clear center spots (or all-clear screens) are used.

[EXA1a]

But what I wanted to know is, if this problem could be caused because the diopter setting is wrong, before I spend time and effort to experiment with different diopter settings? Or can't this be the diopter setting and does it mean that my mirror or something else isn't properly aligned?
With incorrect diopter setting you can't get a sharp picture at all but you will never see a the focal plane shift.
BUT: It is very well possible that the focusing screen and the sensor are misaligned. That exactly happened with my old D30. It was only detectable with my fast lenses wide open (50/1.4, 100/2.0, 200/2.8) or with my 100/2.8 macro, but there was a consistent backfocusing of the picture vs. the viewfinder with either, manual focus or AF. This kind of misalignment can probably only be fixed by a Canon service.
Instead, bought a 300D and the D30 is gathering dust now...

--Jens--

[Jesper]

Jens, I think you are right. If I turn the diopter knob all the way to +, the image gets blurry and it's impossible to get a sharp close-up image. If I turn it all the way to -, it looks a bit strange in another way but not blurry (at least not when trying to focus something close-up... didn't try, but probably then it would not be possible to see a clear image at infinity).

I made some other shots with my new lens with manual focus and now I do seem to be able to get it right. I probably was a little off with the focus in my first shots. Even when you turn the focus ring a very small amount, the focus changes. I have done macro photos in the past with an old, all-manual camera and extension tubes, but not with a real macro lens. I guess I just need to learn how to use it properly.... :roll:

Here's an example: macro photo (although not at max. magnification) at f/2.8. The DOF is ofcourse very small here. I focussed on the "E" in "NEW".

http://home.hccnet.nl/jesper.de.jong/images/CRW_3569.jpg