What's Wrong with this Picture

KED

I had a busy day shooting a soccer game yesterday, with generally good and in some cases spectacular results and a satisfactory "keeper" ratio. But I also got some mystifying results. I was using a Canon 1D Mk III and Canon EF 70 - 200 f/2.8 IS L zoom lens with a 1.4x extender (IS on in pan-enabling mode), shooting in AI servo in burst mode but generally shooting only one frame at a time. I ran the following shots through Digital Zoom to see where the focal point was, and it was just where I wanted it to be, yet the results speak for themselves. In this one, the focal point was the right thigh of the player in white (but the picture is only in focus on #6 in the background):


In this one the focal point was right on #7's number:


Here, on #3's right knee:


The Mk III was known to have had some AF problems, but this one has a serial number well outside the range of identified problems (and manufactured at a time when the problem was supposed to have been fixed at the factory), and I'm generally hesitant to blame the equipment anyway, but it's clearly not a motion blur problem either.

Does anyone see a common problem among these non-keepers?

wizzy

They are defenitly out of focus. Looks like the focus was not estabished yet, and is still trying to get focus.

If it's back focus, on the second and third shot, there should be something sharp, or sharper behind the focus point. But there isn't. In the second shot it looks like a front focus, nr 17 on the right in front, seems sharper then the focused point.

The third is not focused anywhere.....

Looks like as if the AF is not fast enough to follow the subject, or that the initial focus is to slow for the three shots, and that you 'fired' before the focus is established, just when the AF is still 'hunting".

xris

Just a thought, but did you make sure you selected the correct focus point or are you letting the camera do it? No. 1 is sharp to the left, no. 2 is sharp to the right. and no 3 looks as if it may be sharp in the extreme foreground?

KED

xris wrote:

Just a thought, but did you make sure you selected the correct focus point or are you letting the camera do it? No. 1 is sharp to the left, no. 2 is sharp to the right. and no 3 looks as if it may be sharp in the extreme foreground?

Nope, I picked the focal points and was on the body in every case, right where I wanted to be. I have selected the center AF point in the 45-point array, with an assist from the surrounding 6 points if the camera needs it. That "could" explain the errant focus on #6 in the first shot, except that I had my real subject right on the number.

KED

wizzy wrote:

They are defenitly out of focus. Looks like the focus was not estabished yet, and is still trying to get focus.

If it's back focus, on the second and third shot, there should be something sharp, or sharper behind the focus point. But there isn't. In the second shot it looks like a front focus, nr 17 on the right in front, seems sharper then the focused point.

The third is not focused anywhere.....

Looks like as if the AF is not fast enough to follow the subject, or that the initial focus is to slow for the three shots, and that you 'fired' before the focus is established, just when the AF is still 'hunting".

This is Canon's state of the art camera. If it's not fast enough nothing is.

rwells

KED,

The last picture, the one where nothing is in focus, is not uncommon (for my gear) to have one of those per shoot. (250 ~ 1200 shots)

The others, I just don't know. I wouldn't want to jump on any bandwagon and say its the MkIII, although I certainly don't think its the lens


I'd say some controlled testing is in order to systematically figure out what's going on. Right now it sounds/looks like you are having sporadic results. You'll never be able to trace the culprit down without some kind of controlled testing.

Maybe like shooting moving cars coming down the street. Shoot them coming toward your direction, then test shooting them at a cross street.

The MkIII initially had issues with tracking subjects coming fairly straight on to you.

Let us know what your test results are.

BTW, I'm envious of that new MkIII

jfriend

KED wrote:

I had a busy day shooting a soccer game yesterday, with generally good and in some cases spectacular results and a satisfactory "keeper" ratio. But I also got some mystifying results. ...
Does anyone see a common problem among these non-keepers?

I looked at the original version of #1 and the grass behind the desired player is what got focus. There are a number of possible reasons for this. I don't know Canon's auto-focus system settings so I'll talk generically from what I know about Nikon's. Here are some possible causes:

• You weren't using a dynamic focus setting that will track the player and keep the player while they are moving and you somehow acquired focus when the player was further away and that's where focus stayed.
• You were using dynamic focus, but sometime during tracking of the player, the main focus sensor slipped off the target player and locked onto the grass behind. This is easy to do and happens to me sometimes when shooting soccer.
• When shooting action with fast shutter speeds (these look like around 1/1500th), I find that image stabilization sometimes causes blurry photos and often causes a focus system delay while the IS attempts to do the initial stabilization. I turn image stabilization off for all sports shooting. I only use it for people and landscape shots.
• Some of the multi-sensor modes can cause focus to not go to the intended target, even if that's what you aim the center sensor at. For example, Nikon has a closest object mode that will focus on the closest object that is seen among a group of focus sensors. There are apparently a few circumstances where that is useful, but I've never found sports to be one of those places where it works. What mutli-sensor mode are you using? Can you describe how it selects focus among the different sensors being used?
• Any software program that tells you where focus was after the fact can't really know what happened during the acquisition of focus. It can tell you what focus sensor originally locked focus, but it can't tell you if either of the above two scenarios happened so all I think it's telling you in this case is that you didn't have the wrong sensor selected as the active sensor.

When you took these shots, what was your focus methodology? Did you acquire focus on the intended subject with a half press, then track the subject with the center focus sensor staying on the subject 100% of the time until you were ready to shoot and then pressed the shutter all the way? Or did you aim and shoot, pressing the shutter down all in one motion? Does your Canon have a setting that determines whether the shutter will wait until auto-focus is acquired vs. respond immediately to your press even if it hasn't gotten focus yet?

Shot #2 is focused on white player #2. Again, you just missed your target, likely for one of the same reasons listed above.

As others have said, all of shot #3 is out of focus. It looks to me like the foreground grass is slightly more in focus than anyplace else in the image. I would guess that your lens was in the middle of trying to acquire focus. For some reason, it hunted through the range and the exact moment you recorded was a point where it was set to focus at about 10' (or somewhere close) on it's hunt through the range to find focus. The background is clearly way out of focus, so I doubt it was set anywhere near infinity. Your shutter speed is 1/2500th, so it's hard to imagine this could have been camera shake unless you were flinging the camera from one side to another as fast as you could (which I doubt). There's a tiny possiblity this could be caused by the IS. The way IS works is it tries to keep your image stable on the sensor by manipulating some optics as your lens moves. It has a limited amount of range that it can function in. When it hits the end of it's range, it has to get back into the middle of the range in order to keep working. For that brief moment that it's moving from the end of the range back to the middle of it's range, it's likely moving pretty quickly and if you take a shot in that momentary window, you may get a blurry shot. Because the foreground is not quite as blurred as the background, I don't think this is what happened to you, but I turn stablization off with any shutter speed over about 1/640th just to make sure it never affects my sports shots.

So, I think #1 and #2 are just missed focus. You did not successfully lock focus on the desired subject and keep it there before taking the shot.

#3 is something else, probably the camera in the middle of trying to acquire focus.

On many Nikon cameras, there is a setting that determines whether the camera forces auto-focus before taking a shot. If your Canon has something similar, I would suggest turning it on until you solve these problems. It has a downside that it usually slows down the fps because the camera has to verify focus between each frame. But, if you are getting a lot hit rate on good focus, it's better to work on fixing that with a little sacrifice in fps until you work out the technique issue. After all, out-of-focus shots are worthless so it's of no use to record 5 of them per second anyway.

KED

rwells wrote:

KED,

The last picture, the one where nothing is in focus, is not uncommon (for my gear) to have one of those per shoot. (250 ~ 1200 shots)

The others, I just don't know. I wouldn't want to jump on any bandwagon and say its the MkIII, although I certainly don't think its the lens


I'd say some controlled testing is in order to systematically figure out what's going on. Right now it sounds/looks like you are having sporadic results. You'll never be able to trace the culprit down without some kind of controlled testing.

Maybe like shooting moving cars coming down the street. Shoot them coming toward your direction, then test shooting them at a cross street.

The MkIII initially had issues with tracking subjects coming fairly straight on to you.

Let us know what your test results are.

BTW, I'm envious of that new MkIII

Don't be so envious. I went through major hoops to be sure that I got one that was well beyond the serial number range that have been recalled for the AF problem on the theory (supported by none other than my boys at B&H) that the problem had been identified and corrected at the build level. So guess what? I showed these same shots to Canon last night and they want me to send the camera in! :cry

Antonio Correia

Isn't, by any chance, the Auto-focus switched OFF on the lens ?
Some kind of un-voluntary action, movement ...

KED

jfriend wrote:

I looked at the original version of #1 and the grass behind the desired player is what got focus. There are a number of possible reasons for this. I don't know Canon's auto-focus system settings so I'll talk generically from what I know about Nikon's. Here are some possible causes:

• You weren't using a dynamic focus setting that will track the player and keep the player while they are moving and you somehow acquired focus when the player was further away and that's where focus stayed.
• You were using dynamic focus, but sometime during tracking of the player, the main focus sensor slipped off the target player and locked onto the grass behind. This is easy to do and happens to me sometimes when shooting soccer.
• When shooting action with fast shutter speeds (these look like around 1/1500th), I find that image stabilization sometimes causes blurry photos and often causes a focus system delay while the IS attempts to do the initial stabilization. I turn image stabilization off for all sports shooting. I only use it for people and landscape shots.
• Some of the multi-sensor modes can cause focus to not go to the intended target, even if that's what you aim the center sensor at. For example, Nikon has a closest object mode that will focus on the closest object that is seen among a group of focus sensors. There are apparently a few circumstances where that is useful, but I've never found sports to be one of those places where it works. What mutli-sensor mode are you using? Can you describe how it selects focus among the different sensors being used?
• Any software program that tells you where focus was after the fact can't really know what happened during the acquisition of focus. It can tell you what focus sensor originally locked focus, but it can't tell you if either of the above two scenarios happened so all I think it's telling you in this case is that you didn't have the wrong sensor selected as the active sensor.

When you took these shots, what was your focus methodology? Did you acquire focus on the intended subject with a half press, then track the subject with the center focus sensor staying on the subject 100% of the time until you were ready to shoot and then pressed the shutter all the way? Or did you aim and shoot, pressing the shutter down all in one motion? Does your Canon have a setting that determines whether the shutter will wait until auto-focus is acquired vs. respond immediately to your press even if it hasn't gotten focus yet?

Shot #2 is focused on white player #2. Again, you just missed your target, likely for one of the same reasons listed above.

As others have said, all of shot #3 is out of focus. It looks to me like the foreground grass is slightly more in focus than anyplace else in the image. I would guess that your lens was in the middle of trying to acquire focus. For some reason, it hunted through the range and the exact moment you recorded was a point where it was set to focus at about 10' (or somewhere close) on it's hunt through the range to find focus. The background is clearly way out of focus, so I doubt it was set anywhere near infinity. Your shutter speed is 1/2500th, so it's hard to imagine this could have been camera shake unless you were flinging the camera from one side to another as fast as you could (which I doubt). There's a tiny possiblity this could be caused by the IS. The way IS works is it tries to keep your image stable on the sensor by manipulating some optics as your lens moves. It has a limited amount of range that it can function in. When it hits the end of it's range, it has to get back into the middle of the range in order to keep working. For that brief moment that it's moving from the end of the range back to the middle of it's range, it's likely moving pretty quickly and if you take a shot in that momentary window, you may get a blurry shot. Because the foreground is not quite as blurred as the background, I don't think this is what happened to you, but I turn stablization off with any shutter speed over about 1/640th just to make sure it never affects my sports shots.

So, I think #1 and #2 are just missed focus. You did not successfully lock focus on the desired subject and keep it there before taking the shot.

#3 is something else, probably the camera in the middle of trying to acquire focus.

On many Nikon cameras, there is a setting that determines whether the camera forces auto-focus before taking a shot. If your Canon has something similar, I would suggest turning it on until you solve these problems. It has a downside that it usually slows down the fps because the camera has to verify focus between each frame. But, if you are getting a lot hit rate on good focus, it's better to work on fixing that with a little sacrifice in fps until you work out the technique issue. After all, out-of-focus shots are worthless so it's of no use to record 5 of them per second anyway.

Thanks for all of that - very interesting stuff and a whole lot of new variables to consider in future shooting situations. I'm especially curious about the IS. In general, I am constantly tracking the action in AI Servo using the back button, then exposing opportunistically, and this camera should never be outpaced by human motion. Anyway, for now, per my post above, Canon thinks it's their camera's problem and have asked me to send it in!

KED

KED wrote:

Thanks for all of that - very interesting stuff and a whole lot of new variables to consider in future shooting situations. I'm especially curious about the IS. In general, I am constantly tracking the action in AI Servo using the back button, then exposing opportunistically, and this camera should never be outpaced by human motion. Anyway, for now, per my post above, Canon thinks it's their camera's problem and have asked me to send it in!

Thanks to everyone for your input. For now I can blame it on the camera. It's not like it NEVER works, and the day was far from a total loss:

natephoto

Any reply from canon?

I'm considering purchasing a new Mark III, and am happy to come across a recent review addressing the auto-focus issue... I hope it's fixed.

Thanks!
Nate

KED

natephoto wrote:

Any reply from canon?

I'm considering purchasing a new Mark III, and am happy to come across a recent review addressing the auto-focus issue... I hope it's fixed.

Thanks!
Nate

I did hear from Canon and my advice is to wait for Rob Galbreath's research to be published, now scheduled for late this week. His website, where he has published exhaustively about the AF problem, is:

www.robgalbraith.com/bins/index.asp.

See my post at the bottom of this page:

www.dgrin.com/showthread.php?t=74047&page=2

gsgary

I have a 1Dmk1 i always set AI focus speed to moderatley slow then if someone crosses the path of the player you are shooting it dosn't switch focus as easy as having it on fast focus, i can't see the first shots but looking at that last shot i would say it is not camera error, you need to learn how this camera works, football and rugby i always shoot wide open to blur the back ground

natephoto

gsgary wrote:

I have a 1Dmk1 i always set AI focus speed to moderatley slow then if someone crosses the path of the player you are shooting it dosn't switch focus as easy as having it on fast focus, i can't see the first shots but looking at that last shot i would say it is not camera error, you need to learn how this camera works, football and rugby i always shoot wide open to blur the back ground

Canon has acknowledged that it is a camera problem with the new 1D Mark III.

gsgary

natephoto wrote:

Canon has acknowledged that it is a camera problem with the new 1D Mark III.

Soom have the problem not all

KED

gsgary wrote:

I have a 1Dmk1 i always set AI focus speed to moderatley slow then if someone crosses the path of the player you are shooting it dosn't switch focus as easy as having it on fast focus, i can't see the first shots but looking at that last shot i would say it is not camera error, you need to learn how this camera works, football and rugby i always shoot wide open to blur the back ground

The AF speed recommendation is a good one and is endorsed by Canon. As far as learning how the camera works, I do know. As I have mentioned elsewhere in this thread, Canon themselves reviewed the images (no longer posted), and concluded that the problem was with the camera, not the photographer (for a change). They did NOT acknowledge that it was the specific sub-mirror assembly-related AF problem, but I have now read enough about that to be certain that it was -- they symptoms are identical. Anyway, I'm now on my third Mk III body, but haven't had a chance to really put it to the test.