Focus Bracketing R5 Questions

wyotex43n

EOS M6 Mark II
Jan 24, 2016
67
46
I get what I think are unusual results using Focus Bracketing on my R5. This may be that I do not understand the menu correctly.
I assumed you set the first focus point to the the closest focus point and then the camera would move to the next calculated distance based on focus length, f-stop and Dof. If you put in 5 exposures it would take five in sequence moving the focus point out each time to slightly overlap the depth of field with the previous exposure.
First, Is this how it works or does anyone have a good explanation of how the algorithm and the menu setting correlate together?

So I had what I thought were unexpected results. This caused me to take a number of test shots on my dining table and from my deck.

Below are the test results from shooting on by dining table. The closest object was 3 feet away and the far wall about 12 feet.

Please note that several times the camera does not take the set number of shots.

I am on the latest firmware.

I get similar results with all lenses.



RF 24-105 f 4 L

Number Increment MM fstop actual number of photos taken Last image

5 4 24 8 5 blurry

5 4 50 8 5 blurry

5 4 70 8 5 blurry

5 4 105 8 5 blurry



10 4 24 8 6 blurry

10 4 50 8 10 blurry

10 4 70 8 10 blurry

10 4 105 8 10 blurry



10 6 24 8 10 blurry

10 6 50 8 10 blurry

10 6 105 8 10 blurry

10 10 24 8 3 blurry

10 10 50 8 5 blurry

10 10 105 8 10 blurry



RF 15-35 f2.8 L

10 10 24 8 3 Blurry

10 10 35 8 3 blurry



I also did a number of test shots shooting from my deck. In all cases the last shot or two or always blurry. As if the camera has decided to default to some out of focus position. What is odd about that is the next to last photo is not always at infinity.
 

Czardoom

EOS RP
Jan 27, 2020
346
733
I think you need to experiment more with the increment setting and the number of shots. It does NOT automatically set the focal distances to slightly overlap with the previous shot. You need to experiment with the increment setting (which will vary a lot depending on the distance to your subject) to find the best increment to get overlap and not gaps between what is in focus.

I haven't used the focus stacking with Canon, but have done so with other brands. My usual total distance that I want in focus is usually less than 6 inches (let's say a few flowers that are all slightly different distances away). For that length of distance, with the camera maybe 3 or 4 feet away from the subject) an increment of 5 usually works with maybe to 7-8 shots. If you are fairly close to your subject but want things in focus covering a distance of a few feet, than my guess is that you will need many, many more shots, perhaps many dozens. There is unfortunately no formula for figuring out the increment that I know of. For fairly close up shooting a I have done, the focal distance may be changing about 1/2 inch at a time. This will be quite different I believe, if you are shooting landscapes where you are much more distant from your subject.

Hopefully other with more experience will chime in.
 

wyotex43n

EOS M6 Mark II
Jan 24, 2016
67
46
The camera stops if the focus got to infinity.
That is my assumption also but why is the last shot blurry. I tried it outside and I get similar results. It seems to get to the last focus point it calculates and then goes to some unfocused setting.
 

wyotex43n

EOS M6 Mark II
Jan 24, 2016
67
46
I think you need to experiment more with the increment setting and the number of shots. It does NOT automatically set the focal distances to slightly overlap with the previous shot. You need to experiment with the increment setting (which will vary a lot depending on the distance to your subject) to find the best increment to get overlap and not gaps between what is in focus.

I haven't used the focus stacking with Canon, but have done so with other brands. My usual total distance that I want in focus is usually less than 6 inches (let's say a few flowers that are all slightly different distances away). For that length of distance, with the camera maybe 3 or 4 feet away from the subject) an increment of 5 usually works with maybe to 7-8 shots. If you are fairly close to your subject but want things in focus covering a distance of a few feet, than my guess is that you will need many, many more shots, perhaps many dozens. There is unfortunately no formula for figuring out the increment that I know of. For fairly close up shooting a I have done, the focal distance may be changing about 1/2 inch at a time. This will be quite different I believe, if you are shooting landscapes where you are much more distant from your subject.

Hopefully other with more experience will chime in.
Its the landscape shots where I first noticed this because a few out of focus shots on a closeup of a flower seemed logical. I which Canon would give a little more explanation. Thanks for the reply.
 

AUGS

EOS 90D
CR Pro
Feb 13, 2012
105
14
Sydney, Australia
Disclaimer: I do not have an R5 or mirrorless lenses, so cannot confirm my thoughts below.

I read this article quite a while ago as the process had me intrigued:
Reading your settings, I would guess that the increment is set too high and your aperture of f/8 has a significant depth of field to start with, that the camera focus point gets to infinity very quickly.
Maybe try setting the increment to "1" (fine or small change) and aperture to f/4 or f/2.8 (shallow depth of field) and see if this gives better results. This would be even more important with wider focal lengths.
Hope this helps.
 

wyotex43n

EOS M6 Mark II
Jan 24, 2016
67
46
Disclaimer: I do not have an R5 or mirrorless lenses, so cannot confirm my thoughts below.

I read this article quite a while ago as the process had me intrigued:
Reading your settings, I would guess that the increment is set too high and your aperture of f/8 has a significant depth of field to start with, that the camera focus point gets to infinity very quickly.
Maybe try setting the increment to "1" (fine or small change) and aperture to f/4 or f/2.8 (shallow depth of field) and see if this gives better results. This would be even more important with wider focal lengths.
Hope this helps.
Thanks so much for that link. It was helpful. I have done some more testing and the results are consistent with the article. It does explain why some setting result in fewer images and why the last image is usually blurry. I actually video recorded the lens focus distance progression by turning the distance feature on the lcd. It definitely takes photos past infinity. The key seems to be for each situation and lens you have to experiment a little to understand what will happen. In the past when I had used focus stacking for landscape I had used a Dof chart to give me some idea of how many images to take. I would say for landscape adding a few images to the number is a safe bet. For closer work the number has to be much higher to insure you get what you want.