Archived posting to the Leica Users Group, 2001/07/22

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Subject: Re: [Leica] Re: Digital Leica and reality
From: Johnny Deadman <john@pinkheadedbug.com>
Date: Sun, 22 Jul 2001 21:11:46 -0400

on 7/22/01 8:30 PM, Austin Franklin at darkroom@ix.netcom.com wrote:

> You will never ever be able to %100 digitize every bit of information on the
> film.  Film grains are random in shape.  But, what is important, is you do
> not need to.  It's an absurd, and irrelevant goal to try to.  Show me images
> where the precise grain shape is important to the image.  Not, just that the
> image has grain (that's no problem), but that the very structure of every
> film grain is important.

not only that, but grain is essentially a sampling artefact

what's important is the image that created the grain

(of course if you like the grain stick with film!)

when you consider the grain as noise, a 35mm (say) APX400 or TX neg has
*effectively* about the same amount of image information as a 4 Mp digital
image. My 35mm APX negs start to fall apart at magnifications of more than
about 10x, and a 4 Mp image enlarged to 11x14 is having the same problems in
a different way (it looks a bit soft... but still has that amazing grainless
quality of course, whereas the silver film is graining out)

6 Mp gives me an image to play with that is roughly 2000x3000 pixels. But
those are grainless pixels. For those of you who are used to scanning film I
can't emphasise how much that lack of grain noise changes the equation.
Upsampling and interpolation and sharpening all work *far* better in the
absence of grain noise.

- -- 
John Brownlow

http://www.pinkheadedbug.com

ICQ: 109343205