Archived posting to the Leica Users Group, 2004/08/13

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Subject: [Leica] Chromes get more grainy with underexposure too
From: jonathan at openhealth.org (Jonathan Borden)
Date: Fri Aug 13 09:07:36 2004
References: <6E7FDD3B-ECCB-11D8-9EE5-000A95BA5A2C@openhealth.org> <p05111000bd41ee9c69ee@[192.168.1.2]>

Karen Nakamura wrote:

>> This chrome was impossible to print but saved via high resolution 
>> scanning and lots of photoshop curves.
>>
>> http://jborden.org/etc/index.cgi/photos/paris-91.html
>
>
>
> Hmm... you did a valiant job but its still very grainy, there's almost 
> no shadow detail and the skin tones are bad. Photoshop can do magic 
> but still ....

For sure. This was a case where I had to use all of my evolving 
photoshop expertise to get the detail in the hair. Now of course I could 
have reduced the grain by painting in details with the tablet but the 
point of this was to use purely algorithmic techniques (i.e. only 
enhance the information that is already present on the film). I could do 
better at grain reduction through really fancy custom convolution 
kernels, but life is too short and this image isn't that important.

What interested me about this slide was the color. FWIW the color gamut 
on the original slide, and scan, is *way* out of what a web based JPEG 
or Adobe RBG(1998) can represent. We are talking intense yellow (and 
orange) here. I picked this slide because all of these techniques 
require the 48 bit layer facilities in Photoshop CS.

In any case, this isn't intended to be a pretty picture. It is supposed 
to look harsh, with posterlike colors, and the golfball size grain adds 
to this effect. No?

Jonathan


Replies: Reply from george at imagist.com (George Lottermoser) ([Leica] Chromes get more grainy with underexposure too)
In reply to: Message from jonathan at openhealth.org (Jonathan Borden) ([Leica] Chromes get more grainy with underexposure too)
Message from mail at gpsy.com (Karen Nakamura) ([Leica] Chromes get more grainy with underexposure too)