Compact drumscanner

[georgl]

I'm preparing a post regarding different resolution and aperture settings for my blog. But here is a "sneak peak" ;-) of a Portra 400-scan with different aperture settings (-5 is smallest, so 10µm, 0 is standard and +5 is the biggest setting) @6000ppi:
I used a different upload service this time, I hope everybody can see it:
http://www1.picturepush.com/photo/a/...mg/8661279.jpg

[tjvitale]

Seems to me this has been discussed before.

Opening the aperture softens the image, we know the results. I'd make a series of tests on a relevant area of a particular negative (or several representative negatives) with a grain structure you face often and critically observe the affects of "aperture size on output."

Remember that grain is dependent on image density, and image detail [in the specific area of the image] above and beyond the film emulsion itself. Film type is the main factor influencing grain.

Then, grain on a specific piece of film will also be influenced by (a) lens used [resolution limits], (b) f-stop which limits resolution, (c) developing [e.g., (d) grain shaping using Pyro in B&W], (e) hand holding, (f) shutter speed [jiggle] and (h-m) some other factors that slip my mind at the moment. Point is: the "grain" target is moving and relevant to a specific bit of grain structure you need to eliminate, modify or soften.

I have looked at grain under the microscope. It just keeps getting smaller and changing as you increase the magnification. Those Kodak authors had it right, appreciation of grain depends on how you are observing it. And, remember, our visual system and brain are in the mix, we can only resolve at about 270-300-330 ppi or 6-7 lp/mm. Our brains are hardwired to find patterns in everything. Our nature is not that of a machine, but rather a helpful system that facilitates finding order so we can make sense of things. Its a feature, not a bug. We have machines that can be dispassionate and precise if we use them as such.

On the other side of the problem, I have never tested the issue of who has the best resampling math. I believe, however, that it come down to which algorithm "you" like the best, or "best suits" the issue you are trying to overcome. Sometimes, it comes down to which methodology "solved a particular problem in the past" (when you were paying attention to that bit of detail), while most of the time we stay out-of-the-weeds so we can get "other" stuff done.

Adobe has several resampling methods in Photoshop. There must be something written on the topic. Or maybe one of the developers, who is online such as Jeff Scwaee (sp?), or one of the very few others I have seen from time to time, has wisdom to offer on why PS has included one or more of those methods of resampling. Pity about Bruce Fraser, he could have helped with this one!

I always say "do the experiment" and evaluate the results. Tell us if you have time. This is why "I" can be very slow at my day job, I'm always experimenting, until I'm forced to get some "work that pays" out the door.

Cheers

Tim