Scanning dark Kodachrome with VueScan
Joe Sands
What are some ways to get decent results scanning dark (underexposed?)
slides with VueScan. I'm scanning 30-50 year old Kodachrome with a
Nikon coolscan IV and v7.6.69 of VueScan. I get fantastic results
from slides that are properly exposed but underexposed slides turn out
very noisy (grainy). Dark areas exhibit the most noise and don't look
black. Playing with curves in Nikonscan software gives a smoother,
less grainy look with black dark areas. I'd prefer to use VueScan
because it is faster and VueScan's IR clean handles Kodachrome better
that ICE. But so far, I have to run my problem slides through
Nikonscan to get the best results. What works for you?
Thanks in advance and happy scanning!
Joe Sands
-
clipping? You can even try .01 but I haven't experienced much difference.
The scan will be flat but contain close to the maximum amount of data. You
can then adjust this data in PS with curves to boost the contrast, color,
etc.
Next, have your tried the "long exposure pass" option in VS? It makes two
scans and then averages them. Sometimes it does a decent job.
Doug
--
Doug's "MF Film Holder" for batch scanning "strips" of 120/220 medium format
film:
http://home.earthlink.net/~dougfisher/holder/mfholderintro.html
Joe Sands
> clipping
Yes. Thanks for the tip. Another that worked for me was to move the
white point slider in the preview window to the left until the image
data just started to clip. The default scan of the underexposed slide
set the white point far to the right of the "whitest" pixels.
> Next, have your tried the "long exposure pass" option in VS? It makes two
> scans and then averages them. Sometimes it does a decent job.
Tried this too. Didn't seem to be much improved over a single scan.
I guess the Nikon IV does a pretty decent job with one pass!
Does anyone know if you can adjust the LED intensity (analog gain?) in
VueScan?
Thanks to all for you input.
Joe
Bart van der Wolf
"Joe Sands" <jsa...@usfamily.net> wrote in message
news:baafb34c.03120...@posting.google.com...
SNIP
> Does anyone know if you can adjust the LED intensity (analog gain?) in
> VueScan?
What is called "gain" is actually exposure time. VueScan allows that for
scanners that allow to change the exposure time, which will also change the
total scan time.
Bart
Erik Krause
you wrote...
> Tried this too. Didn't seem to be much improved over a single scan.
> I guess the Nikon IV does a pretty decent job with one pass!
It does, but I found significant improvement in shadow noise.
Unfortunately there seems to be a bug that causes an integer overflow
somewhere: http://ecogeo.free.fr/ls4000_lep.jpg
This is an example from the coolscan LS 4000 (not by me). For the LS 40
I found the effect only for some negatives, and for negatives long
exposure pass is not necessary.
> Does anyone know if you can adjust the LED intensity (analog gain?) in
> VueScan?
Yes. Choose 'Lock Exposure' on the Input Tab (only visible with 'All
Options'), then you get an input field.
--
Erik Krause
Digital contrast problems: http://www.erik-krause.de/contrast
Joe Sands
> somewhere: http://ecogeo.free.fr/ls4000_lep.jpg
>
> This is an example from the coolscan LS 4000 (not by me). For the LS 40
> I found the effect only for some negatives, and for negatives long
> exposure pass is not necessary.
Yes. I see this behavior on clipped highlights of Kodachrome images
from my LS 40 using VueScan's long exposure pass.
>
> > Does anyone know if you can adjust the LED intensity (analog gain?) in
> > VueScan?
>
> Yes. Choose 'Lock Exposure' on the Input Tab (only visible with 'All
> Options'), then you get an input field.
There it is! Thanks Erik!
Joe