Getting too dark pictures with Vuescan - can't change exposure

[Alfonso]

How can I increase exposure in Vuescan to open up shadow detail in
dark photographs?

I have tinkered for hours with this without success. Tried
checking/unchecking Lock image color, cropping the original, masking
off white areas with black paper, increasing number of passes, etc.
Read the help too.

Of course I can lighten the scanned file in software, but that just
gives gray shadows without any detail.

The Epson software that came with the scanner does a much better job
of this. Lighter images, detail in the shadows. I don't get it... I
have heard such good things about VueScan. It's supposed to give me
control, isn't it?

I need to save the scans as Raw files. The Epson software doesn't
allow that AFAIK.

Perfection 3170 photo, Vuescan 8.1.16, Win XP.

By the way, I used to get better results with an older Perfection 1200
and Vuescan 8.1.12 - lighter scans and better shadow detail, although
still no way to control exposure that I could find.

Alfonso

 

[Fernando]

How can I increase exposure in Vuescan to open up shadow detail in
dark photographs?

If your particular Epson model supports it (my 2450 does), there is a
"Lock Exposure" checkbox that activates an Exposure slider, in the
first "tab" (named "Input").
You have to activate "Advanced" mode.

Bye!

Fernando

 

[Alfonso]

If your particular Epson model supports it (my 2450 does), there is a
"Lock Exposure" checkbox that activates an Exposure slider, in the
first "tab" (named "Input").
You have to activate "Advanced" mode.

Bye!

Fernando

Thanks for your response. I have a "Lock image color" checkbox. If I
check it, no slider appears. Maybe it depends on the Epson model.

I think the option on mine just allows you to keep exposure the same
for a bunch of scans, presumably after the exposure has been set
automatically by a previous scan.

A.

 

[Dan M]

Thanks for the great tip. I tried this on a really dark, old Kodachrome
slide that I'd been unable to get a decent scan from and was finally
seeing some success --- then the scanner died! Turning if off and then
on didn't help. I unplugged it for a while and then plugged it back in
and it started up, but the Viewscan preview button wouldn't work.

Then I went into Nikon scan and it worked -- and this time I did
finally get good scans from slides that I'd been unable to scan before
now. Maybe the scanner settings somehow got reset to their factory
defaults? Whatever happened, I'm now getting good results with these
slides.

Dan

 

[Bart van der Wolf]

SNIP

I have a "Lock image color" checkbox. If I check it, no slider
appears. Maybe it depends on the Epson model.

Did you do another Preview after checking the Lock image checkbox?

Bart

 

[Alfonso]

SNIP

Did you do another Preview after checking the Lock image checkbox?

Bart

Yes...makes no difference.

The better test is to do another preview without the Lock being
checked, but with a darker or lighter original. That might cause the
autoexposure to set a different exposure. THEN set the Lock...
hopefully that will lock a different exposure. Tried that, but makes
no difference.

It is possible that with VueScan, the 3170 always uses the minimum
exposure.

With Epson software, it uses more exposure, because the scans come out
lighter, and there is more shadow detail.

Alfonso

 

[Don]

Thanks for the great tip. I tried this on a really dark, old Kodachrome
slide that I'd been unable to get a decent scan from and was finally
seeing some success --- then the scanner died! Turning if off and then
on didn't help. I unplugged it for a while and then plugged it back in
and it started up, but the Viewscan preview button wouldn't work.

Then I went into Nikon scan and it worked -- and this time I did
finally get good scans from slides that I'd been unable to scan before
now. Maybe the scanner settings somehow got reset to their factory
defaults? Whatever happened, I'm now getting good results with these
slides.

You may want to try a different VueScan version. It's a known fact
that VueScan bugs regularly pop in and out, seemingly at random.

I've been wrestling with Kodachromes for some time now and find that
NikonScan does what it's supposed to. At the very least it's reliable.
Mind you, I scan "raw" and do all the post-processing in Photoshop
afterwards.

Don.

 

[Don]

Yes...makes no difference.

The better test is to do another preview without the Lock being
checked, but with a darker or lighter original. That might cause the
autoexposure to set a different exposure. THEN set the Lock...
hopefully that will lock a different exposure. Tried that, but makes
no difference.

It is possible that with VueScan, the 3170 always uses the minimum
exposure.

With Epson software, it uses more exposure, because the scans come out
lighter, and there is more shadow detail.

When I tested VueScan a couple of years ago there were some serious
bugs when setting the exposure manually. For example, using any value
above 100 would produced a "randomly" exposed scan. Looking at the
value afterward shows it's been "secretly rolled back" to 100!? Doing
another scan at 100 would then produce a different scan so exposure
used in the first scan appeared truly random.

Also, there is a permanent Preview-bug in VueScan whereby the preview
suddenly goes into funny colors. The scan is OK but the preview is
totally unrelated to the actually scanned image. The general advice
from hadcore VueScan users is to "ignore the preview"... :-/

As always, deleting the INI file may "solve" this for a while, but the
preview inevitably gets corrupted eventually. This seems as one of the
most persistent VueScan bugs, older even than the infamous Minolta
stripes.

Don.

 

[Erik Krause]

The Epson software that came with the scanner does a much better job
of this. Lighter images, detail in the shadows. I don't get it... I
have heard such good things about VueScan. It's supposed to give me
control, isn't it?

I need to save the scans as Raw files. The Epson software doesn't
allow that AFAIK.

Did you have a look at the raw files? If you saved them with 48 bit
they should be very dark in your image editor (Gamma 1.0 space) but if
you pull up the gamma you should see into the shadows. If detail is
present something with your vuescan settings is wrong, but hence you
need raw files anyway this shouldn't bother you for the moment.

If shadow detail isn't present in the raw files (but is visible in
scans from the same photographs with Epson software) then most likely
vuescan does not support your scanner properly. In this case send a bug
report to Ed Hamrick (as specified on the vuescan support page).