Quote: Also, don't forget that the V7xx have two lenses and each one focuses at a different point. When you switch between film with film holder and film with film area guide via the software, that is how you are switching lenses.
Doug
That's true but I thought the second lens was for 6,400dpi.
To amplify on the spacers each holder has a 3 way height adjustment (of which no mention is made in the documentation!) giving a film height adjustment of 2.5, 3.0 or 3.5mm to allow for film curling and fine adjustment of the scanning focus. (Acknoledgement to Stock Agency Forum which suggests that 3.5mm is best for medium format to allow for curling).