<p>Rex,<br>
I'll offer another endorsement for the Minolta Dual Scan series as an option for you. I've owned and used a number of scanners, including a Dual Scan III, a Nikon LS V, an Epson V500 (the predecessor of your V550, I think) and a Nikon LS 8000. <br>
The Dual Scan was the first in the series, and it was really quite respectable, and they look to be available now at low prices, admittedly in unknown condition. One of the major limitations, with respect to the Nikons, is the absence of IR-based noise reduction (called ICE by Nikon). This is a very good feature, but it can't be used for conventional black and white negatives, so it probably isn't relevant to your planned uses. (ICE does work with chromogenic black and white films.)<br>
The Nikon LS V had higher resolution than the Dual Scan, and the scans were sharper, but not hugely so. On the other hand, the LS V is very good at picking up the tiniest scratches on a negative, an effect that I think is due to the direct LED illumination. The Dual Scan uses a tiny fluorescent tube that gives more diffuse illumination and seemed less prone to picking up this kind of noise.<br>
One challenge that arises with scanning negatives is the enhancement of grain patterns. This is sometimes called "grain aliasing", but I don't believe it is an aliasing effect. Without going into the argument about what really causes it, it is a real effect and its magnitude seems to depend on multiple factors, including the film type the developer (for conventional B&W) and the scanner. The effect may have been a bit worse with the Dual Scan than the LS V, but I saw it with both. The best solution that I found was one of the noise reduction programs, or careful choice of film and developer. I have had good luck with Neat Image, but there are others.<br>
For the risk involved, I would be very tempted to try a Dual Scan III or IV for your needs. (I think the earlier models had significantly lower resolution.)<br>
I hope that these comments are of some help.<br>
David</p>