AF micro-adjustment on Canon 7D

[Brian Steele-Drew]

I have had my kit [7D body and a 400mm F5.6 lens] about six months. In that time I have had a lot of focusing issues which I put down at first to my lack of experience with a fairly large lens that does not have lens stabilization. But after reading many camera forums it seems that I am not alone in the not getting "pin sharp" shots with a 7D. So I read with great interest Arash Hazeghi article on AF micro-adjustment. My first question is: does the 7D have a front/back focusing problem?. Concerning the AF MA test there are a couple of things I would like to get clarification on. Viewing at 200% on live view the image appears to "breath or throb" slightly?, making adjustment extremely difficult, is this normal or is there some tiny movement coming from somewhere effecting the AF?. Before doing the live view test I did a series of shots of a bank note 9m away and adjusted the MA by an increment of 1 between shots. My sharpest shot was at +9. What I find confusing is when I do the live view test whether the camera is set on zero or +9 the focus looks the same [fairly sharp]. If I start at zero [on the camera] and "click" nine to the right the live view is very soft. If I start at +9 [on the camera] and "click" nine to the left the live view is very soft.

[arash_hazeghi]

Hi Brian,
Welcome to BPN.
sorry you are having problems with focus. I can tell you from experience 99% of the time MA is not needed (especially with prime lenses) and it is all shooter's technique. The 7D does not have a front/back focus problem, the internet is just full of inexperienced users who are quick to blame their gear. If the LV image appears moving then your setup is not stable enough. It is not possible to do consistent MA if the setup is not rock solid, you will just get random results. What kind of tripod/head are using ?

[Brian Steele-Drew]

Thanks for a prompt reply Arash. This is my problem I do not have a very stable tripod so I used a stout table with a bean bag, otherwise followed your procedure. I was alone and used a cable release. You mentioned shooters technique, I photograph from a vehicle using a stable flat base mounted on the car window with a bean bag. Whats frustrating and confusing is that I have had some keepers as low as 160 shutter speed and soft shots taken at over 2000. Ah well.........the Agony and Ecstasy of photography!. Thanks for the welcome Arash. This is the first time I have joined a forum, as you say, there is a lot of cyber babble out there!.

[Markus Jais]

I did MA on my 7D with the EF 4/300L IS and with the 4/70-200L IS. The 4/70-200L IS was also with Canon before I had the 7D (my 40D does not have MA) but they didn't seem to fix it correctly so I did some MA.

This is not a camera problem but a lens problem as Arash already wrote. My 3.5/180L Macro and the 4/500L IS work just (also with 1.4x).

Maybe you can borrow a tripod. I agree with Arash: Without a rock solid support doing MA adjustments is not possible or will result in the wrong settings.

That sad, I highly recommend getting a good tripod + head. There are many situations in nature photography when it is invaluable.

Markus

[Roger Clark]

Thanks for a prompt reply Arash. This is my problem I do not have a very stable tripod so I used a stout table with a bean bag, otherwise followed your procedure. I was alone and used a cable release. You mentioned shooters technique, I photograph from a vehicle using a stable flat base mounted on the car window with a bean bag. Whats frustrating and confusing is that I have had some keepers as low as 160 shutter speed and soft shots taken at over 2000. Ah well.........the Agony and Ecstasy of photography!. Thanks for the welcome Arash. This is the first time I have joined a forum, as you say, there is a lot of cyber babble out there!.

Hello Brian,

The camera on a beanbag on a table is a very stable setup (assuming a sturdyy table). It should do fine for microadjustments. I too photograph from a beanbag from vehicles, and do microadjustments in the field with the beanbag. My methods are described here:

http://www.clarkvision.com/articles/microadjustment/

However, it sounds that maybe you have other issues. Are you using a single AF point with no expansion? If you have multiple AF points, another AF point can lock on to a background or foreground object. In general, the AF system will lock onto the brightest high contrast object in the active AF points. That may be a blade of grass or twig near but just in front of or behind your subject.. I use a single AF point most of the time with no expansion, and only in some situations do I turn on AF expansion, or use all AF points.

Roger

[arash_hazeghi]

Hi Brian,

If you can see the LV image move you need a more stable setup. Also when you say "cable release" I assume you mean remote release using EOS utility as described in my procedure?

It would be helpful if you can post an example of the photos that came out soft.

[Brian Steele-Drew]

Arash unfortunately I have deleted those shots but will try again in the next couple of days. I use a Canon remote switch [RS-80N3]. Could spot focus be the problem? I will try with a single centre focus on the next test. Thanks very much I do appreciate your advice.
Sorry if you get this twice as my connection cut off as I sent.

[Brian Steele-Drew]

Thanks Roger for an extremely interesting article on MA. I use a single spot focus most of the time [move it around for framing] but for birds in flight I use a cluster of five for easier tracking. Could this be the problem [spot focus] should I do MA with just a single centre point? I am thinking of getting a "Manfrotto 393 long lens mount". Do you have any experience with this mount? I was going to add a jpeg but cannot as I am new to this, it wants an URL?
Brian

[Roger Clark]

Thanks Roger for an extremely interesting article on MA. I use a single spot focus most of the time [move it around for framing] but for birds in flight I use a cluster of five for easier tracking. Could this be the problem [spot focus] should I do MA with just a single centre point? I am thinking of getting a "Manfrotto 393 long lens mount". Do you have any experience with this mount? I was going to add a jpeg but cannot as I am new to this, it wants an URL?
Brian

Hi Brian,
To post an image as a forum participant, you need to post it on a web site and make a URL in your post that points to the image. This may help:
http://www.birdphotographers.net/forums/showthread.php/80485-Posting-Instructions-and-Guidelines

Regarding a cluster of AF points, depending on the situation, it could throw focus off of what is desired. For example, instead of choosing the head, it could choose a wing tip, and if the bird is coming at an angle, then focus on the head would be off.

Roger

[arash_hazeghi]

Arash unfortunately I have deleted those shots but will try again in the next couple of days. I use a Canon remote switch [RS-80N3]. Could spot focus be the problem? I will try with a single centre focus on the next test. Thanks very much I do appreciate your advice.
Sorry if you get this twice as my connection cut off as I sent.

Hi Brian,

If you want to use my MA method you need to tether your camera to the PC with the USB cable and use EOS viewer utility to perform remote focus/release operations as explained here:

http://arihazeghiphotography.com/MA-web/

when doing MA use only single point.

good luck.

[Don Lacy]

Hi Brian, You said you shoot from your car do you always turn your engine off when shooting ? If not the vibration form the engine will contribute to soft images even when using a bean bag.

[Steve Uffman]

Brian,

I can tell you for a fact that MA made a huge difference with my 7D. I went from disgruntled with my 7d to being quite happy with it afterwards. There are other 7d owners on here that also found significant MA adjustments were required but the adjustments varied by lens. And then there are others that have super sharp images without the MA.

Certainly, the reference that technique can have a lot to do with it is true. I had a pro check and look at the results and they agreed it needed micro adjustments.

first clue that it was a camera/lens combo problem came when I was standing next to my wife and we both took images on a duckling that was right in front of the hen. Same shooting specs and the focus point was on the ducklings eyes. Her Rebel t2i had the duckling sharp. Mine had the hen sharper. Again both cameras focus points were on the eye of the duckling. (single point also on both cameras) So I sent it back to Canon with copies of the images showing the focus point on both cameras. Canon said it had a backfocus problem and made an adjustment. While I saw some improvement, I quickly learned that in reality there was a need to align with each combo to get the results I wanted.


I used the LensAlign product and did every lens and TC combo. Have had strong confidence in the 7D focus with any of my go to lens combos since then.



To further illustrate the combo issue, is I did the lens align process for my other camera body at the time (5dmKII) and it needed micro adjustments for the various lens combos but of different magnitudes.


Of course focusing strategy can have a lot to do with it....but you indicated that you use single point most of the time and 5 point some. i do the same but 5 point only in certain situations (i.e. clean background)

Steve