ULF Minimal Focusing Discussion

[Bob Salomon]

Look up documents by Dr Walter E Schön in Germany.

[Corran]

Perhaps explaining what that has to do with the discussion would be helpful, or even better, an actual source and relevant information.

[Corran]

One more thought on this topic, that I shared with Michael in an email discussion.

I think it's possible that the sharpness that Michael is attributing to his usage of wider apertures could simply be due to DOF. Namely, that the foreground objects are sharp while the background recedes slightly outside of the DOF, giving the perceived effect of a sharper-looking (foreground) image. Same as many people attribute "3D-pop" to some lenses, which is often just nice bokeh effects and a DOF that separate the subject from the background. And this could be a very valid reason to use those apertures, and my image or any image could very well be subjectively "better" due to this slight pop in the foreground items. One could even become very accustomed to this look and effect and compose/focus subconsciously seeing this on the GG.

I have certainly shot plenty of images where I thought later I could have used a wider aperture so as to eliminate the distraction of a background fully in focus. The usage of DOF in this way is certainly something I try to think about, though I do tend to default to maximum DOF if I do not have a very specific subject I am trying to emphasize relative to the background. I imagine there could be some subtler effects in the look of the DOF using such apertures as f/22 and f/32 in ULF, compared to just 4x5.

[Bob Salomon]

Perhaps explaining what that has to do with the discussion would be helpful, or even better, an actual source and relevant information.

He writes most of the technical papers for Rodenstock and Schneider.

[Tin Can]

So, in the first paper, 'Less tilt is more'?

And Leonard Evens, author of paper #1 is also a source in paper #2.

Not to belabor this topic but I happened to find this interesting (and heavily math-focused) article with regard to DOF and a tilted lens:

https://sites.math.northwestern.edu/...s/tilt_dof.pdf

I took particular interest in the last paragraph of p. 10 on regarding sharpness at the boundaries of the DOF.

Also this discussion on DOF and specifically diffraction could be helpful (again, very very math focused):

http://www.largeformatphotography.in...DoFinDepth.pdf

[Corran]

I'm not sure what the takeaway is on the first paper. I can't quite get a grasp on how this all balances out between formats either. I point this out because I think it's interesting and there's a lot more going on "under the hood" so to speak.

He writes most of the technical papers for Rodenstock and Schneider.

http://www.weschoen.de/scheimpflug-rechner2.html

Cool, I'll get started on my doctorate in Deutsche and get back to everyone.

[Bob Salomon]

I'm not sure what the takeaway is on the first paper. I can't quite get a grasp on how this all balances out between formats either. I point this out because I think it's interesting and there's a lot more going on "under the hood" so to speak.



http://www.weschoen.de/scheimpflug-rechner2.html

Cool, I'll get started on my doctorate in Deutsche and get back to everyone.

He is fluent in English, ask him for the English, if available.

[Corran]

Bob, that was tongue-in-cheek. Google Translate shows it is a basic explanation of the Scheimpflug Rule. If he has a specific paper that goes into depth about this topic (DOF given tilt, also vs. formats) that is similar or more helpful than the two papers I linked in post #30 that would be great, but otherwise it's kinda like telling a math class with a specific question to go look up Pythagoras or Archimedes.

This is all academic though and since I didn't record exact measurements like tilt angle and such on my photo, I can't mathematically calculate the supposed DOF.