8x HR NA 0.32 + α7R IV 4 Image Pixel Shift Mode

[Duke]

The transition from focus to OOF is different with telecentric optic, I think the change is more abrupt

Nope, not that either. If that's what you're seeing, then I expect it's a matter of other fixed aberrations in the non-telecentric lens that obscure the onset of the particular variable aberration we call "out of focus".

I think EdmundOptics article pretty much covers it. The "perceived focus depth" is on the other level, because the out-of-focus blur is much less, or bokeh, if you will, is much more "composed", reminiscent of the image.
The same effect shows in photographic lenses, F-50mm/1.4 for example, the various lenses from the different manufacturers each have their own characteristic bokeh, despite having the same focal length and aperture, because each has its own optical design and order of telecentricity.

[rjlittlefield]

the various lenses from the different manufacturers each have their own characteristic bokeh, despite having the same focal length and aperture, because each has its own optical design and order of telecentricity.

If I understand your words correctly, then I disagree with you regarding bokeh and telecentricity. The issue that different lenses have different bokeh is well documented as being due to other aberrations, primarily over- or under-corrected spherical aberration. This is what causes the sort of asymmetric blurs, with bright center versus bright edge on opposite sides of focus, that are described for example at https://www.kenrockwell.com/tech/bokeh.htm and https://luminous-landscape.com/bokeh/ . This sort of asymmetry has nothing to do with telecentricity.

The Edmund Optics article is talking about a different sort of asymmetry. Here I have highlighted some parts of the relevant paragraph:

It is a common misconception that telecentric lenses inherently have a larger DOF than conventional lenses. While DOF is still ultimately governed by the wavelength and f/# of the lens, it is true that telecentric lenses can have a larger usable DOF than conventional lenses due to the symmetrical blurring on either side of best focus. As the part under inspection shifts toward or away from the lens, it will follow the AFOV (or the chief ray) that is associated with it. In a non-telecentric lens, when an object is moved in and out of focus, the part blurs asymmetrically due to parallax and the magnification change that is associated with its AFOV. Telecentric lenses, however, blur symmetrically since there is no angular component to the FOV. In practice, this means that features such as edges retain their center of mass location; an accurate measurement can still be made when the object is beyond best focus as long as the contrast remains high enough for the algorithm being used by the machine vision system to function properly.

In other words, EO is using the phrase "symmetrical blurring" to mean that the edge only blurs, rather than blurring and shifting position. With a non-telecentric lens, away from image center the blur will move laterally as focus is changed, moving one direction in front of focus and the other direction behind it. With a telecentric lens, it does not. This is not a matter of bokeh. When Edmund Optics says "larger usable DOF", they are describing exactly the same effect that I was referring to when I wrote that

When making measurements, a telecentric lens gives more leeway for positioning errors without messing up the measurement.

So, if we equate "depth of field" with "allowable range of subject positions", then telecentrics give more.

--Rik

[Medwar]

The perfomance of Mitutoyo 10x HR 0.42 is what surprised me in this tests.
I expected it to perform a lot better, maybe on par with 8x 0.32 in terms of resolution, considering that Qioptics has more expensive and complicated design, but Mitutoyo has larger NA. But in practice it looks here like not so huge advancement even over 10x 0.28, of course beating 0.28 in resolution, but loosing totally to 0.32. (In theory 0.42's linear resolution should be >1.5 times more than 0.28's). Maybe I don't see something or the difference will be visible at higher mags? Mitu 10x HR's images here also have a bit strange contrast and color.

[RobertOToole]

The perfomance of Mitutoyo 10x HR 0.42 is what surprised me in this tests.
I expected it to perform a lot better, maybe on par with 8x 0.32 in terms of resolution, considering that Qioptics has more expensive and complicated design, but Mitutoyo has larger NA. But in practice it looks here like not so huge advancement even over 10x 0.28, of course beating 0.28 in resolution, but loosing totally to 0.32. (In theory 0.42's linear resolution should be >1.5 times more than 0.28's). Maybe I don't see something or the difference will be visible at higher mags? Mitu 10x HR's images here also have a bit strange contrast and color.

Yes, I agree about the contrast and color. The 10x HR lens did have higher resolution compared to the 0.28 but the contrast level was probably not as good as a new off-the-shelf copy but that is one of the negatives of testing only one copy at a time. With some of my other tests that I've done, I was able to test multiple copies, up to 5 in one case, but not this time. The 0.42 10x was a loaner and was purchased on the used market. I think a brand new 0.42 would have performed a bit better.

FWIW, the 0.28 10x was supplied directly from Mitutoyo in Japan, and was hand carried by me back the US in my carry-on bag (long story).

Best,

Robert