EOS RP front focus with EF lenses - Please CANON add MFA to RP!

gium wrote:

StefanD wrote:

StefanD wrote:

Did you try focus bracketing to test this? The tests I see here all use a target with sloped rulers at the side which are very hard to setup with millimeter accuracy.

If you use a flat target and start a focus bracket sequence with the camera performing AF for the first frame, you should see an increase in sharpness for the first few frames if the camera is indeed front focusing.

I just did the test I described with my 85 f/1.8 and got a curious result: Using focus bracketing with the minimum setting for "Focus increment", the first two shots were visibly front focused. Shots 3 and 4 were sharp and then focus shifted again. (flat target at about 2.5 meter and f/1.8)

What's curious about this, is that a test shot in single shot mode (so focus bracketing disabled) was as sharp as the 3rd and 4th in the bracket sequence.

Maybe focus bracketing deliberately starts a bit in front of the initial focus setting? (which would make sense, I think)

I realized another way to check focus accuracy: just set the magnification to 10x and then autofocus. This shows that my 85 f/1.8 focuses accurately. No visible front-focus whatsoever.

I looked it up and found https://www.canon-europe.com/pro/stories/eos-r-features-never-knew-existed/

"It essentially entails taking the same shot multiple times, very quickly, while changing the focus point by very small increments, then blending or stacking those images together to make one super-sharp shot."

So I think you're correct with what you said about focus bracketing starting in front of the focus point when doing focus bracketing. And also a good tip do to the 10x magnification view to check if your focus is set correct.,

I just tested it and it indeed moves the focus back a bit at the start of the bracket sequence. I can easily see this in the distance scale of the 85 f/1.8: I first half-press the shutter to focus and when I press the shutter fully, focus distance is decreased a tiny bit.

Increasing the focus increment to 10 makes this easier to see.

Strange thing I noticed, is that focus is moved 1 time more than the number of images in the sequence. I set the number to 2 and I see (and hear) focus being changed 3 times (first time backwards, and then 2 times forward). Not sure why that is...