Thanks again to occamsmonkey for the requested sample. It was perfect for my analysis. Infinite focus is theoretical, IMHO and shooting comparison pics through different phones has lead me to believe practice differs from theory. So here is what I am looking at...
On the 950 XL with an aperture of f/1.9 occamsmonkey supplied a 3840x2160 image that
calculates to 8.3 MP. I then cropped in on a near portion, a mid and a far range.
near
mid
far
I think anyone would agree that the near portion of the image is crystal clear. Check the slats on the stairs and the reflections in the glass.
The mid portion is very nice. Not as sharply defined. Compare the tower of the crane vs the boom. Also the frames around the windows of the building at about the same distance as the cranes. Look at the building on the wooded hill behind the right-most crane. Acceptable.
There does appear to be some softening in the farthest reaches of the picture. Check the taller buildings and the strut work of the bridge. It is still very nice for such a tight crop on an 8 MP image.It is also highly unlikely that one would want a crop so tight on such a far off subject to make a "presentation" pic. I'm still impressed with the quality here.
For comparison, I had some stock on hand from my 1520 with an aperture of f/2.4. The original is 3072x1728 which calculates to 5.3 MP. I was able to crop on a near and a mid portion for comparison.
near
mid
The near and mid results are nearly identical for clarity compared between 1520 and 950 XL and this is what I was after. Confirmation that 950 XL will replicate this clarity over a wide shot when cropped in or viewed on a large screen. The near portion from 950 XL seems even sharper, but I think it benefits from the larger image size of +3 MP and some more favorable lighting. Also, on the cranes, the 950 XL gets help with color contrast vs the sky...
So I am confident that 950 XL's f/1.9 aperture doesn't suffer from the lack I saw on 928.
I also have the exact same scene as the 1520 taken with a 928 on an f/2.0 aperture. The original is 3552x2000 which calculates to 7.1 MP and I have the same near and mid crops.
near
mid
Side by side with the 1520 sample taken seconds apart, the 928 looks softer all over: the original, the near and the mid. Look at the differences in the near crops of the license plate and the cranes and architecture in the mid crop. The 928 samples have significantly more pixels than the same crop on 1520, yet the 1520 handles it better.
I was afraid that since aperture is fixed and does play into depth of field that maybe 950 XL would suffer from what I saw with a wider aperture on 928. I'm glad to see my fears are countered by in use evidence.