EOS R6 - AF not on target on few pictures

Karl_Guttag wrote:

It might help to post a few pictures (preferably full-frame and resolution). Sometimes people think they have one problem when it turns out to be something different. Without a picture is it hard to know

Were you using the shutter button half-press focusing or using the back button focus? Sounds like half-press but just wanted to check.

Any chance the camera moving between focus locking and the shot? Not saying you did but it seems strange the focus lock point was not in focus.

Chris_From_Holland wrote:

Hello,

I'm going through my yesterday concert shots, and I have a bunch of pictures where the AF seems to be way off.

As the lighting was limited and very red (hence high ISO), I'm wondering whether it's simply me hitting the limit of the AF tracking, or if I have to worry further.

EOS R6 + Canon RF 70-200 f/2.8 (Raw only)

Camera set in Fv mode, shutter 1/200, Aperture f/2.8, ISO 8000

AF mode : Face/Eye detection + tracking (priority People)

Servo AF Mode 4 (sensitivity -1, accel +1)

The AF-Point is set on the face (eyes were not detected) and confirmed locked on the face (DPP confirms the red square), but the face is not sharp while the cymbal ~1m in front of the drummer in crisp sharp.

I have this problem on few pictures, and the AF is again spot on the next pictures (face sharp, cymbal not).

I'd lean towards a case of bad luck, but I kindda need to understand to avoid same problem next time

Thanks!

Chris

I can make the raw available on demand, but not widely, as I don't want to breach privacy,
I was indeed using the Back-Button focus, and it might have been moving unknowingly. What puzzles me is the fact that the AF is reported locked

Karl_Guttag wrote:

Chris_From_Holland wrote:

Karl_Guttag wrote:

It might help to post a few pictures (preferably full-frame and resolution). Sometimes people think they have one problem when it turns out to be something different. Without a picture is it hard to know

Were you using the shutter button half-press focusing or using the back button focus? Sounds like half-press but just wanted to check.

Any chance the camera moving between focus locking and the shot? Not saying you did but it seems strange the focus lock point was not in focus.

Chris_From_Holland wrote:

Hello,

I'm going through my yesterday concert shots, and I have a bunch of pictures where the AF seems to be way off.

As the lighting was limited and very red (hence high ISO), I'm wondering whether it's simply me hitting the limit of the AF tracking, or if I have to worry further.

EOS R6 + Canon RF 70-200 f/2.8 (Raw only)

Camera set in Fv mode, shutter 1/200, Aperture f/2.8, ISO 8000

AF mode : Face/Eye detection + tracking (priority People)

Servo AF Mode 4 (sensitivity -1, accel +1)

The AF-Point is set on the face (eyes were not detected) and confirmed locked on the face (DPP confirms the red square), but the face is not sharp while the cymbal ~1m in front of the drummer in crisp sharp.

I have this problem on few pictures, and the AF is again spot on the next pictures (face sharp, cymbal not).

I'd lean towards a case of bad luck, but I kindda need to understand to avoid same problem next time

Thanks!

Chris

I can make the raw available on demand, but not widely, as I don't want to breach privacy,
I was indeed using the Back-Button focus, and it might have been moving unknowingly. What puzzles me is the fact that the AF is reported locked

Understand that posting a picture can be a problem.

I'm still not 100% sure what focus mode you are using. Is say AF-On (only) set to AF-Face-Eye? As another poster pointed out, In servo mode, the shutter will release without the focus being locked on what you want. BUT, you should not get a red focus square on review if the focus was not actively locked at the instant of shooting.

I'm baffled that the RED square appeared in DPP4 if the focus was not locked on that point. As I understand it (and based on some tests), the square means that it actively focused when the shutter went off. Let's say you locked focus, but then your finger came off the back button just before you shot; there should not be one or more RED squares. The same goes for recomposing with a single AF point (you will get a black square but no RED square if the camera is not actively focusing when the picture is shot.

Due to the red square, it seems like the camera thought the AF was locked. Maybe it locked badly on the face in the bad light.

My default AF setup is with two back button focus buttons. With the focus mode set to AI-Servo and a single point focus. The * button is set to eye detect focus (and then moved the AE lock to the AF Point Select button). In this way, I can go with either method based on which button I press. If the eye detection is having a problem (not locking or jumping around), I can quickly to a point focus with the joystick or focus and recompose.

If you don't mind, I'll send you a private message with a download link to the RAWs with the problems.

On this set of "problematic" shots, I was set in SERVO +  Eye tracking + Case 4.
I use SERVO almost always, I use the button "set" to switch from Eye/facing tracking, to spot.

The Red square on is exactly why I'm asking here It's lighted-on on review , but the zone in focus in not the zone in the square (the cymbal is much brighter that the face though).

R2D2 wrote:

Chris_From_Holland wrote:

Karl_Guttag wrote:

Chris_From_Holland wrote:

Karl_Guttag wrote:

It might help to post a few pictures (preferably full-frame and resolution). Sometimes people think they have one problem when it turns out to be something different. Without a picture is it hard to know

Were you using the shutter button half-press focusing or using the back button focus? Sounds like half-press but just wanted to check.

Any chance the camera moving between focus locking and the shot? Not saying you did but it seems strange the focus lock point was not in focus.

Chris_From_Holland wrote:

Hello,

I'm going through my yesterday concert shots, and I have a bunch of pictures where the AF seems to be way off.

As the lighting was limited and very red (hence high ISO), I'm wondering whether it's simply me hitting the limit of the AF tracking, or if I have to worry further.

EOS R6 + Canon RF 70-200 f/2.8 (Raw only)

Camera set in Fv mode, shutter 1/200, Aperture f/2.8, ISO 8000

AF mode : Face/Eye detection + tracking (priority People)

Servo AF Mode 4 (sensitivity -1, accel +1)

The AF-Point is set on the face (eyes were not detected) and confirmed locked on the face (DPP confirms the red square), but the face is not sharp while the cymbal ~1m in front of the drummer in crisp sharp.

I have this problem on few pictures, and the AF is again spot on the next pictures (face sharp, cymbal not).

I'd lean towards a case of bad luck, but I kindda need to understand to avoid same problem next time

Thanks!

Chris

I can make the raw available on demand, but not widely, as I don't want to breach privacy,
I was indeed using the Back-Button focus, and it might have been moving unknowingly. What puzzles me is the fact that the AF is reported locked

Understand that posting a picture can be a problem.

I'm still not 100% sure what focus mode you are using. Is say AF-On (only) set to AF-Face-Eye? As another poster pointed out, In servo mode, the shutter will release without the focus being locked on what you want. BUT, you should not get a red focus square on review if the focus was not actively locked at the instant of shooting.

I'm baffled that the RED square appeared in DPP4 if the focus was not locked on that point. As I understand it (and based on some tests), the square means that it actively focused when the shutter went off. Let's say you locked focus, but then your finger came off the back button just before you shot; there should not be one or more RED squares. The same goes for recomposing with a single AF point (you will get a black square but no RED square if the camera is not actively focusing when the picture is shot.

Due to the red square, it seems like the camera thought the AF was locked. Maybe it locked badly on the face in the bad light.

My default AF setup is with two back button focus buttons. With the focus mode set to AI-Servo and a single point focus. The * button is set to eye detect focus (and then moved the AE lock to the AF Point Select button). In this way, I can go with either method based on which button I press. If the eye detection is having a problem (not locking or jumping around), I can quickly to a point focus with the joystick or focus and recompose.

If you don't mind, I'll send you a private message with a download link to the RAWs with the problems.

On this set of "problematic" shots, I was set in SERVO + Eye tracking + Case 4.
I use SERVO almost always, I use the button "set" to switch from Eye/facing tracking, to spot.

The Red square on is exactly why I'm asking here It's lighted-on on review , but the zone in focus in not the zone in the square (the cymbal is much brighter that the face though).

Don’t need RAWs if you just post some screen shots from DPP (with AF points showing). Do include EXIF tho.

TIA, R2

2 screen shots from one of the photos (With the EXIF + 100% view)

WildImages wrote:

Chris_From_Holland wrote:

Karl_Guttag wrote:

Chris_From_Holland wrote:

Karl_Guttag wrote:

It might help to post a few pictures (preferably full-frame and resolution). Sometimes people think they have one problem when it turns out to be something different. Without a picture is it hard to know

Were you using the shutter button half-press focusing or using the back button focus? Sounds like half-press but just wanted to check.

Any chance the camera moving between focus locking and the shot? Not saying you did but it seems strange the focus lock point was not in focus.

Chris_From_Holland wrote:

Hello,

I'm going through my yesterday concert shots, and I have a bunch of pictures where the AF seems to be way off.

As the lighting was limited and very red (hence high ISO), I'm wondering whether it's simply me hitting the limit of the AF tracking, or if I have to worry further.

EOS R6 + Canon RF 70-200 f/2.8 (Raw only)

Camera set in Fv mode, shutter 1/200, Aperture f/2.8, ISO 8000

AF mode : Face/Eye detection + tracking (priority People)

Servo AF Mode 4 (sensitivity -1, accel +1)

The AF-Point is set on the face (eyes were not detected) and confirmed locked on the face (DPP confirms the red square), but the face is not sharp while the cymbal ~1m in front of the drummer in crisp sharp.

I have this problem on few pictures, and the AF is again spot on the next pictures (face sharp, cymbal not).

I'd lean towards a case of bad luck, but I kindda need to understand to avoid same problem next time

Thanks!

Chris

I can make the raw available on demand, but not widely, as I don't want to breach privacy,
I was indeed using the Back-Button focus, and it might have been moving unknowingly. What puzzles me is the fact that the AF is reported locked

Understand that posting a picture can be a problem.

I'm still not 100% sure what focus mode you are using. Is say AF-On (only) set to AF-Face-Eye? As another poster pointed out, In servo mode, the shutter will release without the focus being locked on what you want. BUT, you should not get a red focus square on review if the focus was not actively locked at the instant of shooting.

I'm baffled that the RED square appeared in DPP4 if the focus was not locked on that point. As I understand it (and based on some tests), the square means that it actively focused when the shutter went off. Let's say you locked focus, but then your finger came off the back button just before you shot; there should not be one or more RED squares. The same goes for recomposing with a single AF point (you will get a black square but no RED square if the camera is not actively focusing when the picture is shot.

Due to the red square, it seems like the camera thought the AF was locked. Maybe it locked badly on the face in the bad light.

My default AF setup is with two back button focus buttons. With the focus mode set to AI-Servo and a single point focus. The * button is set to eye detect focus (and then moved the AE lock to the AF Point Select button). In this way, I can go with either method based on which button I press. If the eye detection is having a problem (not locking or jumping around), I can quickly to a point focus with the joystick or focus and recompose.

If you don't mind, I'll send you a private message with a download link to the RAWs with the problems.

On this set of "problematic" shots, I was set in SERVO + Eye tracking + Case 4.
I use SERVO almost always, I use the button "set" to switch from Eye/facing tracking, to spot.

The Red square on is exactly why I'm asking here It's lighted-on on review , but the zone in focus in not the zone in the square (the cymbal is much brighter that the face though).

To shoot a static subject using AI Servo can indeed produce out of focus images. The drummer should have been seated, not changing positions front to back or side to side. I would have tried "One Shot" in this instance.

I am perplexed though that the red box in DPP confirmed focus. I have no input on this.

The drummer is playing. His head is definitely moving

I posted sample from DPP

R2D2 wrote:

Chris_From_Holland wrote:

Karl_Guttag wrote:

Chris_From_Holland wrote:

Karl_Guttag wrote:

It might help to post a few pictures (preferably full-frame and resolution). Sometimes people think they have one problem when it turns out to be something different. Without a picture is it hard to know

Were you using the shutter button half-press focusing or using the back button focus? Sounds like half-press but just wanted to check.

Any chance the camera moving between focus locking and the shot? Not saying you did but it seems strange the focus lock point was not in focus.

Chris_From_Holland wrote:

Hello,

I'm going through my yesterday concert shots, and I have a bunch of pictures where the AF seems to be way off.

As the lighting was limited and very red (hence high ISO), I'm wondering whether it's simply me hitting the limit of the AF tracking, or if I have to worry further.

EOS R6 + Canon RF 70-200 f/2.8 (Raw only)

Camera set in Fv mode, shutter 1/200, Aperture f/2.8, ISO 8000

AF mode : Face/Eye detection + tracking (priority People)

Servo AF Mode 4 (sensitivity -1, accel +1)

The AF-Point is set on the face (eyes were not detected) and confirmed locked on the face (DPP confirms the red square), but the face is not sharp while the cymbal ~1m in front of the drummer in crisp sharp.

I have this problem on few pictures, and the AF is again spot on the next pictures (face sharp, cymbal not).

I'd lean towards a case of bad luck, but I kindda need to understand to avoid same problem next time

Thanks!

Chris

I can make the raw available on demand, but not widely, as I don't want to breach privacy,
I was indeed using the Back-Button focus, and it might have been moving unknowingly. What puzzles me is the fact that the AF is reported locked

Understand that posting a picture can be a problem.

I'm still not 100% sure what focus mode you are using. Is say AF-On (only) set to AF-Face-Eye? As another poster pointed out, In servo mode, the shutter will release without the focus being locked on what you want. BUT, you should not get a red focus square on review if the focus was not actively locked at the instant of shooting.

I'm baffled that the RED square appeared in DPP4 if the focus was not locked on that point. As I understand it (and based on some tests), the square means that it actively focused when the shutter went off. Let's say you locked focus, but then your finger came off the back button just before you shot; there should not be one or more RED squares. The same goes for recomposing with a single AF point (you will get a black square but no RED square if the camera is not actively focusing when the picture is shot.

Due to the red square, it seems like the camera thought the AF was locked. Maybe it locked badly on the face in the bad light.

My default AF setup is with two back button focus buttons. With the focus mode set to AI-Servo and a single point focus. The * button is set to eye detect focus (and then moved the AE lock to the AF Point Select button). In this way, I can go with either method based on which button I press. If the eye detection is having a problem (not locking or jumping around), I can quickly to a point focus with the joystick or focus and recompose.

If you don't mind, I'll send you a private message with a download link to the RAWs with the problems.

On this set of "problematic" shots, I was set in SERVO + Eye tracking + Case 4.
I use SERVO almost always, I use the button "set" to switch from Eye/facing tracking, to spot.

The Red square on is exactly why I'm asking here It's lighted-on on review , but the zone in focus in not the zone in the square (the cymbal is much brighter that the face though).

Don’t need RAWs if you just post some screen shots from DPP (with AF points showing). Do include EXIF tho.

TIA, R2

One more photo:

R2D2 wrote:

Chris_From_Holland wrote:

R2D2 wrote:

Don’t need RAWs if you just post some screen shots from DPP (with AF points showing). Do include EXIF tho.

TIA, R2

One more photo:

Thanks for these. I've seen this phenomenon reported here before (here's one of the threads)...

https://www.dpreview.com/forums/thread/4551441

I think the AF algorithms try to paint a happy face on occasion (indicating AF lock when not actually in focus ). The cymbals just seem to be a much better AF target than the face (esp in lower light), even when the cymbals are not under the reported AF square.

There are still occasions esp in low light (IME) where Spot AF produces better accuracy. In fact, I suspect that you will get close to a 100% hit rate under these conditions (vs Face/Eye detect).

R2

ps. I've always suspected that the AF frame designation is actually done post-shot, and is not a real-time indicator of focus. Just a theory...

The thread is indeed this behavior.
I'm not surprised, I'm not shooting in the easiest condition either
I do switch between Spot AF & Tracking, but until now, I was seeing clear hesitation of the AF the the EVF. It's the first time I see this this specific case (and well, this photo was cool).

I love so much my R6, that I tend to forget that it may have limits Hence I'm still learning its limits

Karl_Guttag wrote:

Per other comments, I think the red focus square is cheated sometimes in bad lighting.

I think I can replicate this one with my R5 if the subject is moving. Based on some experiments, there seems to be a lag between face/eye detection and focus locking. Probably made worse by poor lighting. I did the experiment in reverse and moved the camera aimed at a mannequin head with similar shutter, f-number, and ISO settings (i.e. in dim light). The focus box was moved in the direction of the camera and the focus was messed up (not just with motion blur). The focus box was lagging behind the subject. I think if the camera was steady and the subject move, the camera's focus could be messed up.

Per my much earlier comment, You might want to experiment with having two back buttons and uses a point focus. A least it might be worth a try.

When I looked at the information you provided, it does seem like you were correct and have a real problem, which makes it impossible to solve by doing something differently. I'm reminded of a Mark Twain story (condensed version below):

Mark Twain once wrote about a lady whose health was failing and who had no bad habits like drinking or smoking to give up. There she was, quipped Twain, a foundering ship with no ballast to throw overboard to lighten the load.

Full Quote here: https://quoteinvestigator.com/2011/04/24/sinking-vessel/

Chris_From_Holland wrote:

R2D2 wrote:

Chris_From_Holland wrote:

R2D2 wrote:

Don’t need RAWs if you just post some screen shots from DPP (with AF points showing). Do include EXIF tho.

TIA, R2

One more photo:

Thanks for these. I've seen this phenomenon reported here before (here's one of the threads)...

https://www.dpreview.com/forums/thread/4551441

I think the AF algorithms try to paint a happy face on occasion (indicating AF lock when not actually in focus ). The cymbals just seem to be a much better AF target than the face (esp in lower light), even when the cymbals are not under the reported AF square.

There are still occasions esp in low light (IME) where Spot AF produces better accuracy. In fact, I suspect that you will get close to a 100% hit rate under these conditions (vs Face/Eye detect).

R2

ps. I've always suspected that the AF frame designation is actually done post-shot, and is not a real-time indicator of focus. Just a theory...

The thread is indeed this behavior.
I'm not surprised, I'm not shooting in the easiest condition either
I do switch between Spot AF & Tracking, but until now, I was seeing clear hesitation of the AF the the EVF. It's the first time I see this this specific case (and well, this photo was cool).

I love so much my R6, that I tend to forget that it may have limits Hence I'm still learning its limits

Thank you for your extended answer and tests.

Knowing this, I'll switch to spot AF next time, and will give a try to your buttons assignment.

Understanding the behaviour is half way managing it. So I know what to try.

Not to mention that the R6 AF is, and stay, a total killer when it comes to precision. The missed are very rare (and I'm kinda torturing it)

Karl_Guttag wrote:

Chris_From_Holland wrote:

Thank you for your extended answer and tests.

Knowing this, I'll switch to spot AF next time, and will give a try to your buttons assignment.

Understanding the behaviour is half way managing it. So I know what to try.

Not to mention that the R6 AF is, and stay, a total killer when it comes to precision. The missed are very rare (and I'm kinda torturing it)

A few more things might help.

Set the Magnification to button on reviewing the image on the camera to Actual Size from Selected Point (Menu - Playback (blue) - Tab 4 - Magnification - Actual Size (from selected pt)). If you review a shot on the back of the camera and hit the magnifying glass button, this will zoom in the maximum amount to the center of the focus area. This will let you see if you are locking on focus well quickly.

I like to have my AF points displayed on playback so I can see them in the camera (Menu - Playback (blue) - Tab 5 AF point display. This will let you see where the AF point is on the back display. It would not help in this specific case but it might in others.

Whatever software you are using to covert raw is bad. The noise I'm seeing is horrible for ISO 8,000 on an R6 or R5. What did you use? I would highly recommend downloading a free trial of DxO PureRaw or DxO PL4 and using DeepPrime. You should see a huge difference. The difference is minor at low ISO but it is worth 2 to 3 stops better as the ISO goes above about 3,000. If you want, you can send me the RAW file via private message and I will convert it for you to show the difference.

This was an unprocessed RAW. When I saw that the drummer wasn't sharp I didn't spend any more time to even try develop the RAW. So the noise makes sense.

Out of curiosity, I'll sent you the link with the raw

I will setup the magnification on review as displaying the point,. It will surely help (at least to re-shoot immediately).

Next concert is planned over 2 weeks, so I'll to wait a bit to confirm all that

Greg23D wrote:

Hi

not sure if this has any bearing, but isn’t the low light af dependent on a wide lens? And doesn’t the R6 need a f1.2 lens to fully utilise its low light capabilities? That’s like two stops more light than the f2.8 you’re using.

Greg

That definelty can bear here.

F/1.2 is not something I own (and I assume that, would 70-200 F/1.2 exist, it would be close to be totally unaffordable), so i'll always be limiting the AF. Something I need to keep in mind