Sports shooters: single or expanded AF points?

[Ian_of_glos]

Yes, I've seen improved sports AF with the 5DIV, but then I'd consistently read that the 5DIV had significantly better AF than the 5DIII, so I was pleased but not really surprised. I don't take advantage of frame rates very often (I generally shoot one frame at a time, trying to time my shot with the action), but when I have held the shutter, the 5DIV did FEEL faster than the 1 fps improvement would have indicated. I recently bought Lexar 128GB 160 MB/S cards and they are pleasingly fast, too, in either body. With the 5DIV and these cards, even RAW files feel delightfully fast! In regards to differences with the 5DIII, at the same time that I moved to the 5DIV as my primary body, I also got a 100-400II and am using that as my primary lens and that makes specific differences harder to pinpoint. I miss the f/2.8 range of my 70-200 less than I thought I would, but the extra reach of the 100-400II is helping AF AND exposure. With the 70-200, I struggled more with very dark backgrounds in evening soccer and football when the players were on the far side of the field and I usually had to go to manually riding the ISO as players moved through dark and bright parts of the field. With the 100-400, I've noticed that the players are larger in the image and that has made the dark backgrounds a non-issue with exposure. Overall, I'm loving the 5DIV in particular, but also as a partner with the 100-400II.

The 5D mk 4 with the 100-400 ii is my favourite combination for sports as well. I find that 100-400ii is just the right focal length for rugby and football and it is not too heavy. I did rent a 200-400 F4 with the built in extender for one match but it is enormous and it really slowed me down, so I went back to the 100-400 ii.
It would be useful to have a few more frames per second on the 5D mk4 and I have thought about buying a 7D mk2 for sports. However, I am reasonably happy with what I have and I only miss a shot very occasionally.
Why not try switching to AI Servo for a while? You will discard a lot more shots but it is worth it to be sure of capturing every decisive moment in the match.

 

[tpatana]

Interesting. I use 98%+ zone af. I'd use single point only on some special cases. People move too much, single point is not good.

 

[awair]

It might be helpful if we include some screenshots (showing active AF points), to give a better illustration of hits & misses?

I know that added complications in my swimming scenarios include low light > wide open > shallow DOF.

This also tends to influence my choice of single/spot.

The attached image would (probably) have been OOF with either 4 or 8-point surround/assist points.

 

[awair]

On this image, I believe the light/DOF saved me. I would have been better off using any other focussing point/group!

 

[awair]

Whereas this one shows (with the wrong lens) why single point was probably better?

 

[awair]

Last one, I promise: even with 'Automatic Selection' of AF points, didn't quite catch this. (Feedback & tips most welcome...)

 

[Ian_of_glos]

Last one, I promise: even with 'Automatic Selection' of AF points, didn't quite catch this. (Feedback & tips most welcome...)

Thank you for posting your illustrations. The pictures are excellent - especially the swimmer. In this situation where you want to focus precisely on one swimmer and their movement is predictable I agree - I would always use single point AF.
However, for team sports where the players are moving around quickly in all sorts of different directions and I really just want to capture the action around the ball I find that zone AF works best. It can keep up with the action far better than I ever could.
In the picture with the blue rugby player in the scrum cap, I cannot understand why it has focussed on his head. I would have expected it to find enough contrast between his left arm and the ball, or his arm and the shirt sleeve and focus there - which would have been perfect.
With the gymnast (or is it a diver) again I cannot understand why it has chosen a focus point on the thigh. I would have expected it to choose the point with good contrast that is closest to the camera - so either the hands or the area around the head.
Normally I delete any shots that are not in focus but I have a rugby match this Saturday and (at my own risk) I will photograph part of the match with single point AF, part with expanded and part with zone to see if it allows me to illustrate what I am saying. I am expecting more of the shots to be in focus when I use zone, but it will enable me to show what the camera does when I try to use single point AF for rugby.
Incidentally how to you save the pictures that show the AF points? This is probably really obvious but it is not something I have ever tried to do.

 

[awair]

Thank you for posting your illustrations. The pictures are excellent - especially the swimmer. In this situation where you want to focus precisely on one swimmer and their movement is predictable I agree - I would always use single point AF.

Thanks for the feedback Ian.

In the picture with the blue rugby player in the scrum cap, I cannot understand why it has focussed on his head. I would have expected it to find enough contrast between his left arm and the ball, or his arm and the shirt sleeve and focus there - which would have been perfect.

That was me, manual (Spot AF) selection using the top AF point - great when they're running, but didn't anticipate the way he was going to dive! (I was trying to illustrate the disadvantage of my 'usual way', and I was looking for good examples, rather than good images!)

With the gymnast (or is it a diver) again I cannot understand why it has chosen a focus point on the thigh. I would have expected it to choose the point with good contrast that is closest to the camera - so either the hands or the area around the head.

This one, I'm also not sure about either - possibly because it was Case 2 (instead of Case 6)? I have captured this shot successfully on other occasions, but there may have been a little more light then. (BTW It's the start of a swimming heat, off the blocks.)

Incidentally how to you save the pictures that show the AF points? This is probably really obvious but it is not something I have ever tried to do.

Using Canon's DPP software, displaying the AF points and taking a screenshot. Hence the lack of EXIF data.
Apple's Aperture app also does this well (however, a major failure that Lightroom cannot).

 

[Ian_of_glos]

@awair - thanks. I will post some examples after the match, probably on Sunday.

 

[Jack Douglas]

@awair - thanks. I will post some examples after the match, probably on Sunday.

This is educational - thanks - and more please.

Jack

 

[Ian_of_glos]

Some pictures from yesterday's match. The results surprised me.
To start with I used single point AF, but after 15 minutes I was missing too many shots so I switched to expanded AF point.
These are a couple of the pictures taken using Single point AF. I was using AI Servo and high speed continuous so the photos were taken less than a second apart.
What surprised me is that in both cases the AF point was on the green player's leg. I was expecting the AF point to be on the advertising behind him in the out of focus shot.

 

[Ian_of_glos]

Here is another example where I used Single Point AF. This time the focus point is on the blue player's hand which again surprised me. I was expecting to find that the AF point was on the advertising behind the players as this is clearly what is in focus. Is it possible that DPP is not displaying the AF point correctly?
Again I have included a shot that was taken less than a second later and this time the AF point has found the blue player's shorts, so the players are in focus

 

[Ian_of_glos]

After 15 minutes I switched to AF point expansion because too many shots were out of focus when I used single point AF. AF point expansion was a lot better - only one shot was out of focus even though I used this mode for over 25 minutes.
This is the only shot that was out of focus when I was using AF point expansion and this time the AF point is clearly on the advertising. I am willing to accept that I was not quick enough when I tried to place the AF point over the green player who is about to catch the ball.
Before this experiment I was expecting AF point expansion to be just as bad as single point AF - because if the centre AF point was positioned over the advertising then I would expect it to find enough contrast and therefore not use any of the helper AF points. However, in practice it did a cracking job and this was the only shot I missed in 25 minutes of play.

 

[Jack Douglas]

Here is another example where I used Single Point AF. This time the focus point is on the blue player's hand which again surprised me. I was expecting to find that the AF point was on the advertising behind the players as this is clearly what is in focus. Is it possible that DPP is not displaying the AF point correctly?
Again I have included a shot that was taken less than a second later and this time the AF point has found the blue player's shorts, so the players are in focus

This is very much appreciated - taking the time to shoot and then post!

I'm grappling with similar issues with BIF or almost flight. No, DPP is not wrong, it's the AF system being too slow to adjust. I have countless examples of this and even sent some to Canon. Keep in mind that the AF capability diminishes as you go away from one-shot dead center and is worst at the extreme edges even with the best cameras.

Jack

 

[Ian_of_glos]

During the second half of the match I only used zone AF. This is the mode I normally use so I was expecting a higher success rate, but I was surprised to find that there were more out of focus shots than with AF point expansion. There was a total of 6 out of focus shots when I was using zone AF, and I have included some examples below.
In the first example no part of the zone is positioned over a player - clearly my fault and nothing to do with the camera. I had been focussing on the tackle on the right hand side of the picture when the player offloaded the ball, and I ended up mid way between the player being tackled and the player he was passing to.
In the second example - none of the AF points are illuminated - so I have no idea what happened. A split second later the AF seemed to catch up and so the next shot is in focus.
Finally, in the third example again I am confused. The blue player's arm is clearly within the AF zone but the camera has chosen to focus on the spectators behind him. I would have expected it to focus on the player as he is within the AF zone and closer to the camera. Can anyone suggest a reason why it has missed focus in this case?

 

[awair]

Hi Ian,

Thanks for posting these. I had similar results with my 7D2, which went back to Canon twice with no improvement - on the third occasion I told them to keep it.

While I've had the occasional poor result with the 1DX, for the most part any errors have been mine, although I did have a couple (like your Single Point AF 2.jpg), where the focus point clearly identifies a point that is most definitely not focussed.

As Jack says, "it's the AF system being too slow": which AF case were you using, and have you made any customisations? I've used Case 2, 3 & 6 for this kind of scenario, with mixed results - I tend to fall back to Case 2.

 

[awair]

With Case 2, it's my responsibility to keep tracking the subject & the camera takes care of brief interruptions. Errors normally occur when I can't maintain the subject accurately enough, due to lack of anticipation, excess distance or just too many people in the way.

With Case 3, the camera locks on quicker (more responsive), but with Single Point if you fail to track you will get a quick shift to the background!

Case 6 is me giving up (on over-thinking) and wishing for an improvement!

I feel like I have more control and responsibility with Case 2, but still not entirely sure that I have really got the hang of it.

 

[Ian_of_glos]

Here is another example where I used Single Point AF. This time the focus point is on the blue player's hand which again surprised me. I was expecting to find that the AF point was on the advertising behind the players as this is clearly what is in focus. Is it possible that DPP is not displaying the AF point correctly?
Again I have included a shot that was taken less than a second later and this time the AF point has found the blue player's shorts, so the players are in focus

This is very much appreciated - taking the time to shoot and then post!

I'm grappling with similar issues with BIF or almost flight. No, DPP is not wrong, it's the AF system being too slow to adjust. I have countless examples of this and even sent some to Canon. Keep in mind that the AF capability diminishes as you go away from one-shot dead center and is worst at the extreme edges even with the best cameras.

Jack

Jack - thank you for your feedback.
So do you think that if I set AI Servo First Image Priority to Focus Priority then I would have a better success rate? At the moment it is set to Equal Priority because I am worried about there being too much of a delay between pressing the shutter release and the camera taking the first picture in the series. It is only a 5D mark 4 and not really a sports camera, so I understand that I have to make some allowances for that.

 

[Ian_of_glos]

Hi Ian,

Thanks for posting these. I had similar results with my 7D2, which went back to Canon twice with no improvement - on the third occasion I told them to keep it.

While I've had the occasional poor result with the 1DX, for the most part any errors have been mine, although I did have a couple (like your Single Point AF 2.jpg), where the focus point clearly identifies a point that is most definitely not focussed.

As Jack says, "it's the AF system being too slow": which AF case were you using, and have you made any customisations? I've used Case 2, 3 & 6 for this kind of scenario, with mixed results - I tend to fall back to Case 2.

Thank you for your comments.
I am using Case 2 unaltered. This is the best mode for rugby because people frequently run in front of the camera and I don't want the camera to focus on them. Most of the time the camera ignores them and remains focussed on the action.
Rugby players tend to move in one direction and their movements is not really erratic so I don't think cases 5 or 6 would offer any improvement.
When players are running towards the camera they maintain a fairly constant speed so I don't think case 4 is needed either.

 

[Jack Douglas]

Jack - thank you for your feedback.
So do you think that if I set AI Servo First Image Priority to Focus Priority then I would have a better success rate? At the moment it is set to Equal Priority because I am worried about there being too much of a delay between pressing the shutter release and the camera taking the first picture in the series. It is only a 5D mark 4 and not really a sports camera, so I understand that I have to make some allowances for that.

Unfortunately, I'm not even close to being an expert on this but I think the 1st 2nd priority issue may play into the overall performance of the AF in this case. I believe it was Grant Atkinson who delved into that topic and today with a bad headache I can't quite recall - maybe someone can help - I believe he had a series of videos and suggested not using cases at all rather just setting the 3 parameters that constitute the cases, via your personal menu. Seems only one parameter is of greatest importance.

What I can say with authority is that the AF system is not as fast as it needs to be to insure that when a AF point is over a subject, that subject is always going to be in focus.

That's a completely unrealistic expectation especially when using less sensitive points and lenses that may not be the fastest in their drive characteristic. If you think of it, a brain has to analyze some smudgy area and decide what part of it should be in focus taking into account the movement of the camera and the movement of the smudge and then snap the lens into focus at that distance, which probably by now has changed slightly, and also determine when to let the shutter go. Ooooh, quite a task!

Jack