Scanning for stiching in Vuescan

[Dian Cecht]

I'm about half way through a project scanning 200 5x7 glass plate
negatives on my Epson 2450. Since the 2450 will only handle 4x5 I
have to make two scans and stitch then together in photoshop. My
input settings are BW Negative, Archive 2400 dpi, exposure locked.
Color settings are none with the black and white points set to zero
and the remaining sliders set to 1.

With the exposure locked and the color settings identical for each
scan, I would expect that there would be no difference in density
between the first and second scans. In practice, however, often one
side is often visibly lighter than the other.

I can usually fix the problem with a simple gamma adjustment but if
would make my life a lot easier if I could solve the problem Does
anyone have an idea what's going on?

 

[Ed Hamrick]

I'm about half way through a project scanning 200 5x7 glass plate
negatives on my Epson 2450. Since the 2450 will only handle 4x5 I
have to make two scans and stitch then together in photoshop. My
input settings are BW Negative, Archive 2400 dpi, exposure locked.
Color settings are none with the black and white points set to zero
and the remaining sliders set to 1.

You also need to lock the film base color. It's varying with
each scan, which causes the problem you're seeing.

This is described in more detail in the VueScan User's Guide,
in the "Advanced Workflow Suggestions" section.

Regards,
Ed Hamrick