DPP4 What do "Show AF point" messages mean?

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WHAT DOES DPP4 MEAN BY THIS PHRASE?

On page 22 of the current instruction manual for DPP4 (version 4.18.10) the text says a user can view an image's AF points on a computer display in either of two configurations.  Those two are (1) "Show only AF points in focus" and (2) "Show all AF points."

What does the first option mean?  Does it mean that DPP4 will show every in-focus AF point the camera has identified for the image currently being displayed by DPP4 (post processing)? Note that there is no reference here to an AF point or AF points that has/have been determinative in reaching focus for a given image. Indeed, what is the meaning of "in focus" in this context? It limits how many AF points it will "show" to only those that are "in focus."  What if dozens of AF points in an image are "in focus?"  What does Canon intend by this statement? What does this have to do with the procedure of focusing?  What is this displayed information, what is it supposed to tell the user, and how is it (whatever it is) supposed to be useful to the photographer?

[wq9nsc · Accepted solution]

I attached some labeled screen captures from DPP using my 1DX III in various AF modes. 

There is a big difference in AI servo versus single shot for the expansion modes.  In AI servo, initial tracking must begin with the selected center spot but then the expansion is used to help the camera track the subject.  But as you noted, that center point is all that will show in DPP even when clearly one of the other expansion points was used to track and hold focus.  I presume this is just an artifact of showing the center point will always have priority even if it wasn't the one that held focus after initial tracking. 

With AF expansion in single shot mode, the camera will show various points on the focus screen as having achieved focus but in my experience even when multiple points are illuminated at the time of capture, DPP will only display one point in single shot expansion HOWEVER this will be the actual point used and not always the center spot.  In the single shot expansion example below, the selected center point is the middle point 5 down from the top.  At the moment of capture, three points were illuminated as in focus but DPP shows only one used and that is probably indicative of how the camera works selecting only a single point of the usable array of points in expansion mode.

In the full array mode, both AI servo and single shot show multiple points in focus at the point of capture AND DPP also shows multiple points in focus.

AI servo with expansion is very useful in some sports in tracking a fast/erratically moving subject that may be wearing a uniform that doesn't provide good AF characteristics over the entire uniform.  But most of the time I prefer using a single point without expansion, with the 1DX III focus acquisition is extremely responsive and single point gives me the greatest control over picking out exactly what I want in a scene like the last example where a lot is going on but I am following the ball.

RodgerAF expansion, AI servoAF expansion, one shotFull array, AI servoFull array, one shot

1DX III EF 400 f2,8 single point AF

[shadowsports]

Greetings,

Here are the options for displaying AF Points

Option All AF Points

Option Only AF Points in Focus

Worth noting.  Stationary subject.  Its not moving, I'm not moving.  I'm using one shot AF and controlling where the camera will focus.  Servo AF would show a much larger grid of (red) focus points.  Let us know if you have questions. 😀

[wq9nsc]

Excellent explanation by Rick and some of the usefulness is:

1.  Shows what point(s) were in focus according to the camera which is useful for developing a feel for depth of field setup.

2.  For a DSLR, useful if you are assessing if micro-focus adjustment is needed for that lens.

3.  It lets you go back and look at the camera AF setup used to see what worked and what didn't, I did a fair amount of that analysis when shooting various sports right after getting my 1DX II and 1DX III bodies.  It allows you to better choose what array of focus points (single, single precision, single with expansion, zone, etc) tends to work best for a particular situation.

Rodger

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Thanks to both responders.  I have examined thousands (you read that correctly) of images shot with AI Servo, using Single-Point (manual selection), Single-Point Expansion (5 total AF points) and Single-Point Surround (total 9 points).  Not one (you read that right) of those images shows more than one AF point illuminated on the screen, irrespective of subject size, subject placement on the grid, or how many AF points are in the AF mode I have used (single, 5, or 9) in taking the image.  Always and only one point illuminated, and that point is always the center point of the AF mode when using any of these three (single, expansion, surround).  I am not using R series cameras, mine are mirrored Canon DSLRs whose AF systems are copies of the 1-D x and 5D MarkIII systems.

[wq9nsc · Accepted solution]

I attached some labeled screen captures from DPP using my 1DX III in various AF modes. 

There is a big difference in AI servo versus single shot for the expansion modes.  In AI servo, initial tracking must begin with the selected center spot but then the expansion is used to help the camera track the subject.  But as you noted, that center point is all that will show in DPP even when clearly one of the other expansion points was used to track and hold focus.  I presume this is just an artifact of showing the center point will always have priority even if it wasn't the one that held focus after initial tracking. 

With AF expansion in single shot mode, the camera will show various points on the focus screen as having achieved focus but in my experience even when multiple points are illuminated at the time of capture, DPP will only display one point in single shot expansion HOWEVER this will be the actual point used and not always the center spot.  In the single shot expansion example below, the selected center point is the middle point 5 down from the top.  At the moment of capture, three points were illuminated as in focus but DPP shows only one used and that is probably indicative of how the camera works selecting only a single point of the usable array of points in expansion mode.

In the full array mode, both AI servo and single shot show multiple points in focus at the point of capture AND DPP also shows multiple points in focus.

AI servo with expansion is very useful in some sports in tracking a fast/erratically moving subject that may be wearing a uniform that doesn't provide good AF characteristics over the entire uniform.  But most of the time I prefer using a single point without expansion, with the 1DX III focus acquisition is extremely responsive and single point gives me the greatest control over picking out exactly what I want in a scene like the last example where a lot is going on but I am following the ball.

RodgerAF expansion, AI servoAF expansion, one shotFull array, AI servoFull array, one shot

1DX III EF 400 f2,8 single point AF

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Thanks, Rodger.  Roger that. Your response provides needed info not available elsewhere.  I was wanting and trying to use illuminated AF points comparatively between Single Point Expansion and Single Point Surround, to see which cluster configuration appeared to be the most effective for targets such as birds in flight and high-performance aerobatic aircraft.  Prior to your remarks, I was not finding factual information relative to the difference in what DPP displays when shooting with what you call "full array" and when shooting with Single-Point Expansion or Single-Point Surround in AI Servo. Your operative comment is the following, copied from your answer above: "In the full array mode, both AI servo and single shot show multiple points in focus at the point of capture AND DPP also shows multiple points in focus."  Bingo. Why are you the only who knows that?  I wonder why Canon doesn't provide that detail in their camera and DPP documentation. That information could/would/should have saved me hours of reading, writing, and testing.

One perhaps final question, please:  By "full array," I assume you mean Automatic AF Point Selection, as described on pages 30 and 31of the excellent EOS 7D Mark II AF-Setting Guidebook.  I assume you do not mean Large Zone AF or Zone AF (pages 26-29) neither of which could be considered "full array." Please confirm. I virtually always want/need to select the beginning AF point.  Your comments regarding the advisability of using a Single AF Point without Expansion are also well taken, although the referenced EOS 7D Mark II AF-Setting Guidebook states on page 18 that this cannot be done when using Case 6 of the Configuration Tool.  I have successfully used it that way for years.  Thanks again.  Looking forward to your response regarding definition of "full array."

DQ. 

[wq9nsc · Accepted solution]

DQ,

You are welcome!

I did mean automatic when I called it full array.   The 1DX III has so many zone choices plus face and head recognition options that it has a lot of different descriptions.  Using automatic is fun to watch as it tracks objects across the full array of 191 points but it isn't something I find practical for my style of shooting.

I went through the same confusion you did when I got serious about trying different setups for the best tracking in soccer and football and although the point expansion mode is helpful at times, I found that overall my best results were using a single point.  I spent a lot of time studying results from shooting games/matches with different AF setups and some of my PhD background helped there (major in marketing with minors in research methodology and statistics). 

My bias towards single point I think comes from a combination of taking a little workload off of the camera but more importantly it forces the photographer to be 100% "focused" upon the task so the results are partly due to technology but largely due to psychology.  However with birds in flight, I would probably be more biased towards using single point with expansion since the target is smaller and the movement more fast paced and erratic.

I suspect that maybe in a LONG photography session, as the operator grows fatigued then using a focus mode that supplies more assistance becomes ever more valuable.  I am shooting volleyball tonight which is my least favorite sport to shoot.  Maybe I should try putting the 1DX III bodies in full auto/program mode and let them do all of the thinking for me 🙂

The bottom line for me is I love the responsiveness of the optical viewfinder and focus system of Canon's DSLR configuration and I never worry about freezing, overheating, sluggish performance, or battery life 🙂  I still have a pair of 1DX II bodies I use alongside 1DX III bodies and the biggest difference between the two for me is marginally better low light performance with the 1DX III sensor; the way I use the camera doesn't bring into play the additional predictive focus capabilities of the III.

Rodger

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Thanks, and just a parting affirmation. This is from a post on the DP Review Forum in November, 2018, in response to a question that is the same as we are discussing.  Here it is:

Question: How many focus points are you using? And which focus points?

Answer: From our experience the big squares just don’t keep up with fast moving objects and the more squares the worse the accuracy.  Which is why we all use the tiny focus squares, and I’ve noticed one of our photographers switching to a single cross type in the middle to get the keepers we require.

Even the Canon guys who were at an airshow over the weekend were telling everyone to set to a small section of focussing (sic) points, with one even recommending that you use a single point to keep up.

Thanks, once more.  I looked at my entries on this Canon Community Forum and noticed that you and I had quite a good exchange on similar topics five (5) years ago this month on this forum. Thanks for still being there.