If I understand your question correctly you place 4 slides in a transparency adapter, enable Multi Crop
and then Vuescan recognizes (erroneously) that you want to scan 8 slides.
Subsequently it starts scanning all 8 regions where it thinks slides are present.
To only scan the four slides follow these steps:
- Enable
Batch Scan
in the Input
tab.
- Choose
All
in the Batch Scan
options drop-down menu.
- Do a preview scan.
- After that choose
List
instead of All
in the Batch Scan
options.
- Now you have to find out what frame numbers the actual slides have. You can find this by varying the
Frame number
in the Input
tab and noting the frame numbers that actually select a slide. Let's assume Vuescan recognized your 4 slides under frame #1, #4, #5 and #8.
- Now in the text box next to the
Batch List
option write down 1,4,5,8
. This directs Vuescan to only scan these frames.
You can find more information on the commands in the Vuescan manual, especially on page 57 where the Batch List
option is explained.
As my scanner is not supported on my OS anymore I don't have Vuescan installed to show screenshots, but these steps + the manual should be enough.