Any known problems that might affect AF on a 7D with the newly updated firmware?

[Jon Rista]

I recently upgraded my 7D to the newest version of firmware from Canon. I believe it is v2.0.3. I followed the instructions to a T, and the upgrade seemed to go very smoothly. I am quite excited that I can now get over 32 continuous frames at 8fps when I use a UDMA-7 CF card. I don't generally hold the shutter button that long, but when I do successive bursts, I'm able to continue shooting without any slowdown for a MUCH longer time than I was able to before. I have noticed a drawback, however...AF does not seem to maintain its lock on subject, even when the AF point does not move away from the subject. I primarily use the EF 100-400mm f/4.5-5.6 L IS lens, and almost always at 400mm.

Lately I have primarily been into Bird and BIF photography. I only started in February this year, so I am willing to accept that I may simply be doing something wrong here, but I've put a lot of effort into perfecting my AF technique, right from the beginning, so I'd like to make 100% certain there is not something wrong with my camera before I blame myself.

I started at the beginning using rear-button AF. I configured the * button to be my AF activate, and the AF-On to be AE-Lock. I use Spot, Point, and Expansion AF modes. I have my tracking sensitivity set to -1 or -2 for BIF, and 0 for everything else. I have AF/Tracking priority enabled. I have Continuous AF track priority set. Focus search is on. I have the Manual AF pt. selection pattern set to "Continuous" rather than "Stops at AF area edges". Everything else is default. I keep my camera in AI Servo mode...and just press and release the * button to AF and lock for "single shot" if I need to.

I have noticed that when I AF along with a stabilized lens (either on a bean bag or tripod or something to keep it stable), AF will not maintain its lock consistently if I press and hold the * button down. This occurs with both BIF and other birds. With BIF and AF expansion mode, AF will now usually hunt just a bit before locking on, but once it does lock on, it will sometimes hunt just a bit every few frames, and my keeper rate has dropped from around 60% or so (I'm still learning, so its not as high as it could be) to below 40%, sometimes well below. Most of the frames will be mostly in focus, but few will actually be fully in focus. For perching birds, waders, shore birds, I've noticed that even if I keep my selected AF point (single or spot) on the subject and hold down the * button, AF will lock initially, and every few seconds shift slightly out of focus, then a few seconds later might shift back in.

It feels like the AF system's tracking logic has changed, and it won't just hold an AF lock on a focused subject any more. If I'm photographing a shore bird that is walking a shore, I can't simply press the * button once to AF then let go and make some photos...I have to keep the button down to track the bird as it moves towards or away from me. I've even noticed this when photographing birds in my yard...jays in particular (as they are slightly larger birds and easier to keep the AF point on the subject at all times). They tend to lend on a far branch of a tree, then hop closer and closer one branch at a time. AF will not always track them as they move despite keeping the AF point on the bird...sometimes it will keep focus at the original focus plane where AF initially locked onto the subject. I have to release the * button and press it again to force AF to reacquire focus lock on a bird that has moved.

I've tested this fairly extensively on Scrub Jays and Blue Jays in my yard that I attract with seed and peanuts. They are comfortable enough with me that they will spend 10-15 seconds being choosy about which seeds to gulp down or which peanuts to take off and hide for later. That gives me plenty of time to plot a focus point down on their body, hold the AF button down, and see what happens. Even for a generally stationary bird that is well illuminated by sun light with a moderate phase angle (so well lit and good contrast in the detail), AF will lock for a second, shift (usually slightly forward of the subject, but sometimes back as well), then lock again for a second, then shift, etc. The camera is otherwise unmoving, mounted on a tripod, and I just hold down the * button in AI Servo mode. I would expect the subject to remain locked and completely in focus the entire time I hold the * button down, regardless of the slight continuous motions and movements of the birds.

Because of this behavior, I've started getting a FAR higher number of just barely out of focus shots that are blurry enough as to not be useful...all interesting detail, such as feathers, is blurred enough to no barely or longer be visible and noise exhibits more as everything is now smoothish rather than structured detail. I never experienced this before the firmware update. I did have focus misses, however it was obvious to me that it was my fault...usually because I moved the AF point off the subject for just a little too long. My keeper rate was much higher before the firmware update than it is now.

I am hoping I've just screwed up my technique in some way, or am misunderstanding how the AF system is supposed to work, or have my 7D's AF drive configured incorrectly for Birds/BIF. I am really hoping the problem is not the firmware. Has anyone else experienced anything like this with a 7D? I greatly appreciate any information about this.

[Daniel Cadieux]

I'm still on 2.0.0 so I can't comment on the new firmware, but I haven't heard or seen anyhting about 2.0.3 affecting AF.


If I'm photographing a shore bird that is walking a shore, I can't simply press the * button once to AF then let go and make some photos...I have to keep the button down to track the bird as it moves towards or away from me

This is normal in AI Servo and backbutton AF...you have to keep the * pressed to track your moving subject. Letting go of it is like locking focus and of course the subject will move out of the frame as it wanders around. If your subject is stationary and your rig is on a tripod then lock your focus once you've achieved it by letting go of the * button, otherwise the AF will keep correcting ever so slight movements continuously (but not as bad as you describe though). If you ahndhold then keeping the * button pressed is a good idea as we tend to move to and fro much more than we realize. As for your other issues I have not encountered anything like that with my 7D + 100-400 combo. BTW, is your lens micro-adjusted? Perhaps this is why you are getting more OOF frames than expect?

[David Stephens]

Hey Jon, nice to meet you yesterday. Your image choice for your icon is my favorite in your 500px stream.

I'll mount the 500mm on my 7D for a bit this weekend to see if I experience the focus shift you're talking about. I use the half way down shutter release to control my AF, but the results should be similar. Using my 70-200mm I haven't noticed any issue, but that's a lot easier AF because of the short focal length.

[Jon Rista]

Hey Jon, nice to meet you yesterday. Your image choice for your icon is my favorite in your 500px stream.

I'll mount the 500mm on my 7D for a bit this weekend to see if I experience the focus shift you're talking about. I use the half way down shutter release to control my AF, but the results should be similar. Using my 70-200mm I haven't noticed any issue, but that's a lot easier AF because of the short focal length.

Hi David! It was great to meet you yesterday. Always good to meet another fellow nature photographer out in the field. :) Your work is great, was checking it out on Flicker earlier today. With my 7D AF issues, which may simply be how the 7D operates in lower light like we had in the afternoon, and based on what you had to say about the 5D III, I am seriously considering some major upgrades. I may move on to a 5D III and 600mm f/4 L II + 2x TC III next year. That 61pt AF system sounds pretty amazing.


I'm still on 2.0.0 so I can't comment on the new firmware, but I haven't heard or seen anyhting about 2.0.3 affecting AF.


This is normal in AI Servo and backbutton AF...you have to keep the * pressed to track your moving subject. Letting go of it is like locking focus and of course the subject will move out of the frame as it wanders around. If your subject is stationary and your rig is on a tripod then lock your focus once you've achieved it by letting go of the * button, otherwise the AF will keep correcting ever so slight movements continuously (but not as bad as you describe though). If you ahndhold then keeping the * button pressed is a good idea as we tend to move to and fro much more than we realize. As for your other issues I have not encountered anything like that with my 7D + 100-400 combo. BTW, is your lens micro-adjusted? Perhaps this is why you are getting more OOF frames than expect?


Hi Dan, thanks for the reply! My 100-400mm lens has been AFMAed with Reikan FoCal, which seems to do a pretty good job of automatically determining a lenses AF offset and automatically applying an AFMA setting in the camera for you. My lens is currently at a -3 AFMA setting. The behavior I am describing is something I can see in the viewfinder, it's not just something I discover once I'm home and I import. If the 7D locks properly, the bird will usually appear quite sharp in the OVF, and once AF shifts, its clear that it shifted in the OVF as well. Not like a focus shift from the bird to some distant background...more like the shift from a shore bird's head as it faces you to the rear of its tail feathers, then back a few frames later.

Regarding holding the * button, I was just trying to be clear that I experience the problem while tracking, but not just with BIF...it occurs with shore birds as they move up and down the shore as well. If I lock and release, the problem never really exhibits because it doesn't really have the chance to. I usually use a tripod when photographing shore birds and waders. I've experienced this problem with dowitchers, sandpipers, and plovers that wade up and down the shores of Cherry Creek Reservoir here in Colorado. They tend to move away in stages...they'll move down, then poke around for a while. Its when they pause and feed in one area for a while when the problem really seems to exhibit most. They are always on the move, and I try to keep their eyes in focus, so I'm usually holding the * button down even whey they are not strait up moving towards/away from me. So long as I hold down *, focus will hold for a few frames, then shift ever so slightly, then a couple frames later it'll usually find its lock again for a few more frames. Sometimes it will backfocus, then frontfocus, and I have to release and press * again to get it to properly lock.

I was out again at Cherry Creek for about six hours yesterday. I noticed that the problem does not exhibit when there is good light. I managed to get some great shots of a killdeer that was well lit, and I never experienced the focus shift problem. The two times I did experience it were when trying to lock AF onto an American Coot off shore, and another American Coot as well as some Mallards later in the day that were in a shady area of a pond. The coot in particular seemed to cause the 7D some problems. If I used spot AF, or with single point AF when the bird was more shaded than lit, the 7D would hunt within a short range, and when it stopped, it was not always properly in focus. I had the same problem with a Mallard drake when its head was shaded...the 7D would hunt a bit, and when it stopped, it would not always be in focus. If I held the * button down on a moving bird (mallard or coot), sometimes it would lock correctly, sometimes it wouldn't adjust at all, and sometimes it would seem to just lose focus entirely and hunt through the entire range before finally stopping. When it stopped, it was about 50/50 whether it actually focused sharply on my subject, or slightly out of focus.

Seems that the problem occurs in low light on pretty much any bird, or when the AF point is targeting something dark. If I move my selected AF point in single point AF mode off the eye and onto the edge between the birds head and the background (or wherever there seemed to be enough contrast), then AF would succeed in locking properly much more frequently. However trying to AF onto a birds eye when the whole head was shaded, or AF on any part of a dark bird like a Coot, resulted in the whole hit-or-miss AF experience. Is that simply what you get for a $1300 camera and AF system? Should my experiences be better than that, or am I just pushing the limits of what the 7D can do?

[Roger Clark]

Seems that the problem occurs .... when the AF point is targeting something dark.

Hi Jon,

How about posting a screen shot of a full 7d frame with the AF rectangle shown?

The problem you describe is common in situations where there is a brighter subject nearby your subject. For example, a dark bird with a bright background. Example, see:
http://www.clarkvision.com/galleries/gallery.BosqueNWR/web/sandhill.crane.c12.05.2009.img_0720.c-800.html

In the above image, it looks like a very sharp boundary between the edge of the bird in silhouette and the bright background. But while the AF system sees that high contrast edge, it also sees a high brightness with a lot of high contrast in the background. The AF system will, in general, choose the brighter high contrast point. Note too that the actual AF zone has a fuzzy boundary and is larger than the AF rectangle by about a factor of 2. You can check this with the following test:

Choose a bright source with a large dark background. The Moon high in the night sky works well for example, or an isolated street light at night.
Choose a single AF point with no expansion.
Place the bright subject near but not on the AF point and engage the AF system and see if it focuses.
Try different distances to determine how big the AF zone is. Also test up, down, left and right of the AF point.

So if your AF point is on a dark subject (e.g. dark bird, or bird in shadow) with a brighter background, and any part of the full AF zone is on that background, the AF will usually lock onto the background. If the subject is only slightly darker than the background, and the AF zone includes both, the system may hunt between the two.

I have observed this behavior on multiple cameras, including Canon 7D, 5DII, 1DIV, 1DII, 30D and earlier models (I have not tested Nikons for this problem). Understanding this problem should help one in diagnosing different problem situations enabling one to place the AF point at the bets position to achieve best focus.

Roger

[Jon Rista]

Thanks Roger. I'll see if I've kept any of the misfocused frames. I tend to cull in the field, as I have four 16GB cards, and I tend to just go home once they are completely full (which usually happens after about six hours). I try to extend the amount of space I have on my cards as much as possible (I know, I could buy some more, and larger ones at that, but I am trying to save for at least one of Canon's super-telephoto lenses, 300mm f/2.8 II or 600mm f/4 II, and buying a bunch of 32GB or 64GB cards will cut a nice several hundred dollar chunk out of my savings...and if I buy more cards, I'm going to have a hard time resisting buying the fastest and largest I can find, along with a nice USB 3 card reader as well...so I'd probably be out nearly a grand). When I know I've taken a sequence with misses, I tend to delete them right then and there to lengthen my trip. I plan to go out photographing again tomorrow, and I'll keep a closer eye on the context within which the problem occurs.

I've experienced the problem in a few different scenarios, where the behavior was a little different. Photographing shore birds, I would say you nailed the problem. When the problem exhibits, the birds tend to be darker than the background, and the backgrounds sometimes have enough detail that the AF system could probably lock on. Now, I know when I accidentally move the AF point off the subject, and my AF tracking speed is medium, that the chances of it jumping are moderately high. I spend a LOT more time photographing with my camera on a tripod these days, though, and my AF point doesn't stray nearly as much as it did when I hand-held for everything. The odd thing about it is that AF will shift to the rear of my subject, not necessarily jump, just a little bit, even when the AF point has not moved away from my target (usually the eye). This is in contrast with backyard birds, primarily the Jays. When the problem exhibits with them, I am usually hand-holding, but I know of two specific cases where I had the AF point square on the birds head, very close to the eye, for about eight seconds, and it shifted the focal plane towards my by just a few millimeters two to three times in both cases. One bird was a Scrub Jay, the other was a Blue Jay...the birds were actually too-well lit (bright sunlight, such that the head feathers exhibited an iridescent sheen...I figure the oil on them was scattering light.) I figure it is possible something about that particular subject could have posed some problems for the AF system. The interesting thing, though, is that the AF system seems to consistently shift towards me in the "backyard bird" cases, and away from me in the "shore bird" cases.

One additional factor...I am usually pretty free with my AF point usage. I use single point AF, sometimes spot AF, but I rarely limit myself to the center point. I have not yet tried to correlate this problem with specific AF points, but it is possible it only occurs when I use one of the outer points. I tend not to use the outermost four points...the tips of the AF area...all that often, but I use the points of the central grid pretty freely. I even use the core nine points a fair bit with BIF, usually in Expansion AF mode. I've read a few other threads here on BPN where experienced 7D users regularly state that only the center point, possibly in expansion mode, should be used. I'll try to verify tomorrow whether the AF shifting issue only occurs on non-center points. I am always using an f/5.6 lens these days since I am limited to the 100-400 L.

[Roger Clark]

Thanks Roger. I'll see if I've kept any of the misfocused frames. I tend to cull in the field, as I have four 16GB cards, and I tend to just go home once they are completely full (which usually happens after about six hours).

Hi Jon,
Regarding AF issues, please post some examples that include the AF rectangle. That will help diagnose the problem.

But I have to comment on your above statement. 64GB of images in 6 hours, and that is after culling in the field, is an astounding number to me. That's probably over 2500 images in 6 hours, or an image every 8.6 seconds if one did no culling.

I teach "when not to take an image." By that I mean look in the viewfinder and examine foreground and background, composition and lighting. If it is not ideal, that is when not to take the image.

Roger

[Jon Rista]

I am always in high speed mode, and just about every time I release the shutter, I get around 5-6 photos, sometimes more. I used to shoot everything hand-held, and in any given set of shots, there were always some that were a bit blurry, so multiple frames compensated for that. I use a tripod for just about everything now, and my keeper rate is quite high relative to what it was only a few months ago (I used to have maybe 25% keepers, now it is probably 80% or so). I guess I created a rather bad habit by always taking so many frames whenever I press the shutter button...but, you know how it is...bad habits die hard. I cull a lot in post, and Lightroom has a handy feature that bulk-deletes rejects, so it hasn't been a huge deal (and I hope I'll be able to correct my habits in a couple more months assuming I can remain aware of it.)

[John Guastella]

I am always in high speed mode, and just about every time I release the shutter, I get around 5-6 photos, sometimes more.

I assume you know that the shutter has a finite lifespan? By keeping the camera in high-speed continuous, you're going to be facing a shutter replacement very early in the life of the camera.

John

[Jon Rista]

I assume you know that the shutter has a finite lifespan? By keeping the camera in high-speed continuous, you're going to be facing a shutter replacement very early in the life of the camera.

John


Well, the 7D has a 150,000 actuation rating on the shutter. I've taken about bird 33,000 photos this year, and I'm a lot more efficient now than I was when I first started (which was just in February...I used to fire off dozens of shots at a time, so I think 5-6 at a time is an improvement, and I can probably whittle that down to 2-3 at a time before the year is out). I will probably take 40k-45k by the end of the year. That means I'll be replacing my shutter about four years into my 7D's lifetime. I intend to replace the whole camera long before then.

@Roger: Any idea how I can get the AF points to show up? Lightroom does not seem to have that capability. It seems Apple Aperture does, but I don't have a mac. I think I've found a couple sets of shots of one of the jays that demonstrate the problem, if I can figure out how to show the AF point.

[Roger Clark]

@Roger: Any idea how I can get the AF points to show up? Lightroom does not seem to have that capability. It seems Apple Aperture does, but I don't have a mac. I think I've found a couple sets of shots of one of the jays that demonstrate the problem, if I can figure out how to show the AF point.

Hi Jon,

There are 2 ways I know of:
1) use canon's DPP software that came with the camera (or updated software)

2) use a second camera to photograph the lcd screen of your camera with the image displayed on the back.

#1 is preferable (will show better detail).

Roger

[Jon Rista]

Sorry for the lack of reply. I've had some rough weeks at work, and some other issues to deal with lately. I have to find my 7D installation CD so I can install the original version of DPP, as the versions downloadable from Canon's site require the CD to install as well. Hopefully I'll have something with AF points displayed soon.