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Re: [OM] ReBoot [was Long lens multi-thread III, IBIS

Subject: Re: [OM] ReBoot [was Long lens multi-thread III, IBIS
From: Ken Norton <ken@xxxxxxxxxxx>
Date: Thu, 22 May 2014 10:20:34 -0500
Dr. Dubs wrote:
> If you are using Vuescan, the "TIFF Size Reduction" under the Output tab
> creates a smaller file size and has the added effect of improving edge
> sharpness a little bit without introducing artifacts and noise.  Try 2 or
> even 3 to see the effect.

The 2x reduction (which does a 50% resize) of a full-frame 4000dpi
scan results in a file that is similar in size to a 6MP digital
sensor. This is probably the nicest trick I've encountered with
Vuescan to equalize the "film vs. digital" debate and had M.R. done
that a dozen years ago he wouldn't have been so quick to claim that a
3MP camera beat state-of-the-art scans of Provia. The key, though, is
to scan at full resolution and then apply the 50% resize. If you
combine that with the "Grain Reduction", the files are like digital
camera files, but with all the tonal goodness of film.

The Analog to Digital and then the Digital to Analog process of
imaging has a distinct flaw in the area of aliasing. When you scan
film, you get "dot gain" as a result. And then when you output to
inkjet you get "dot gain" again. If there is any grain or noise in the
image, this is amplified. The above identified process helps eliminate
most of the grain dot gain involved which equalizes film scans (of
good quality low-ISO transparency films) with digital camera files.

While you can do the resize and noise reduction in post (and I usually
do), Vuescan does this VERY well and is quicker than doing it by hand.

One reason why I personally tend to do it by hand is that I get to
optimize the resize and cleaning steps for the final output. If I'm
going strictly to inkjet output, letting Vuescan do some heavy lifting
works great. But if I'm sending my files to Millerslab my methods are
better. When sending to the screen, it varies a little depending on if
there are lots of lines or geometric shapes that can cause aliasing
artifacts on the resize.

-- 
Ken Norton
ken@xxxxxxxxxxx
http://www.zone-10.com
-- 
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