Tech Support > Computer Hardware > Scanners > VueScan - bad handling of overexposed negs
VueScan - bad handling of overexposed negs
Posted by Bryan on March 2nd, 2004


I'd like to find out how I can get a decent image from an overexposed
color negative. Apparently, any of the color balance settings on the
Color tab will attempt to tone down the washed-out brightness, which
causes false coloring of the overall image. For instance, the
blue-white sky becomes a dingy, grainy yellow-brown color. I have
tried using the "None" and "Manual" settings without much luck. Has
anyone found a way to correct this and scan these negs so they look
presentable? I can send you an example of an image where this problem
appears if you'd like.

I wouldn't bother trying to make these images look better, except that
when I compare the VueScan results with the photo lab's prints, the
prints look WAY better, color-balance wise. I figured if a photo lab
can figure out how to expose these negatives, VueScan should be able
to duplicate that. For now, I'm scanning in the prints instead of the
negs, but I'd like to do the negs instead.

I am using a HP Photosmart S20 and have VueScan 7.6.75, in case that
makes a difference.

Thanks!
Bryan

Posted by Wilfred van der Vegte on March 3rd, 2004


Bryan wrote:

Have you tried the 'advanced workflow suggestions' in the user manual?
Your problem seems familiar to me - not only with overexposed negs but
also with correctly exposed negs that contain lots of highlights. The
'advanced workflow' mostly seems to make the problem disappear.

--

Wilfred van der Vegte.
Replace 'invalid' by my first name to reply by e-mail

Posted by Bart van der Wolf on March 3rd, 2004



"Wilfred van der Vegte" <invalid@vandervegte.com> wrote in message
news:c241oq$6od$1@news.tudelft.nl...
SNIP
Exactly what I would have suggested, but you beat me to it ;-)

Those 'difficult' color negatives require a bit more attention than a
correct exposure, but there is of course a limit to what can be done after
severe overexposure. However, given the fact that the OP's prints appear to
look sort of acceptable, it is likely that VueScan can do at least a similar
job.

Especially the "Advanced Workflow" and the Right-Mouse-Button click on a
neutral area (non-saturated white works best for negatives) should get one
close to an acceptable rendering of the original scene. If the overexposure
is too extreme, I'd suggest to concentrate on shadow to mid-tone accuracy,
and tweak the highlights afterwards (curves or selective color in Photoshop
if available).

Bart



Posted by Bryan on March 5th, 2004


Thank you, that did help quite a bit. The scans are at least
presentable now, although still not quite as good as the photo lab
prints. There are still some darkish streaks in the direction of the
scan in the highlights (mostly in the sky), but it's way better than
it was before locking film base color and exposure. I had thought
that selecting the correct film type would have done this, but I guess
not.

I notice that it scans more slowly when these "lock" boxes are
checked, even though the scan dpi has not changed. I don't know why,
and I think I won't question it as long as it works. ;-)

Thanks again,
Bryan

"Bart van der Wolf" <bvdwolf@no.spam> wrote in message news:<4045d9b4$0$569$e4fe514c@news.xs4all.nl>...

Posted by Bryan on March 5th, 2004


And by the way, I just wanted to submit my disdain for the cheap
throw-away cameras. Yes, I am trying to scan negatives from one of
these and the quality is terrible to begin with. They load them with
800 film (upside down and backwards, no less!), and then have a cheap
plastic lens and a fixed shutter speed. What do you think will happen
when you take pictures with it in bright sunlight?? :-)

Bryan
"Bart van der Wolf" <bvdwolf@no.spam> wrote in message news:<4045d9b4$0$569$e4fe514c@news.xs4all.nl>...

Posted by Ed Hamrick on March 5th, 2004


"Bryan" <bryan_cass@yahoo.com> wrote:
The scan time is linearly related to "Input|RGB exposure". The
longer the CCD is exposed, the longer the scan takes.

Regards,
Ed Hamrick



Posted by Bryan on March 6th, 2004


Ah, that explains it Ed, thank you. The RGB Exposure is set to 1.981,
so I assume that means it's scanning slower than 1.000 (if that's the
normal setting).

Bryan

"Ed Hamrick" <usenet@hamrick.com> wrote in message news:<c29blv$c60$1@ngspool-d02.news.aol.com>...

Posted by Bryan on March 6th, 2004


Any idea what might be causing the darker streaks in the sky on
overexposed negatives? Could it be CCD noise or something? Or is
VueScan trying too hard to balance the color when it should just be
letting it go white and low-contrast?

Bryan

"Ed Hamrick" <usenet@hamrick.com> wrote in message news:<c29blv$c60$1@ngspool-d02.news.aol.com>...

Posted by Bart van der Wolf on March 6th, 2004



"Bryan" <bryan_cass@yahoo.com> wrote in message
news:d45dbb9a.0403052019.7fff609c@posting.google.c om...
It's related to hardware calibration/initialization (uniform matching the
sensitivity of the CCD elements along the array and between arrays if
appplicable). The remaining differences are most visible in low signal (=
dense) film areas. Try re-calibration from the "Scanner" menu.

Bart




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