The 80/1.7 GF on the GFX 100S has *more* DOF than calculators say

Started 2 months ago | Discussions thread
MOD Hamiltionian Contributing Member • Posts: 929
Re: At f/2.8...

JimKasson wrote:

Hamiltionian wrote:

JimKasson wrote:

...DOF is still greater than the calculators say it should be, but it is more symmetric.

https://blog.kasson.com/gfx-100s/are-dof-calculators-useful-part-2/

Interesting. Makes sense that we are seeing more symmetry, but I am still somewhat puzzled that we are seeing less dof than the calculators predict. At the narrower aperture I would have expected it to be pretty close.

I didn't see how the images were processed. Sharpening? Something funny going on in the demosaicing?

Lr with defaults except for Sharpness amount 20, radius 1, detail 0, and WB Cloudy.

But whatever the processing was affected all the images, since I used the f/4 shots for the series as the starting place for the Matlab processing.

My instinct is to suggest that the order of the blur and sharpening operations could matter, but after playing around in photoshop I can't demonstrate that in any noticeable way.  Sharpening unlikely to be the issue here.

Of course, I didn't have image of what the lens was putting down on the sensor at 600 nm sampling resolution. I just had the image captured at 3.76 um sampling resolution. I did enlarge that to 900% before doing the CoC simulation, and I used bilinear interpolation for that enlargement. Maybe I lost some sharpness there.

Maybe, seems pretty reasonable to me though and unlikely to cause a significant loss in image sharpness.

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