david_goldenberg1

<p>"The lens head unscrews from the DR focusing body, but the non-DR Summicron of the same vintage is fixed."<br> I'm pretty sure that the rigid Summicron, introduced in 1957, had the same removable optical unit as the DR. I have read in various places that the Leitz technicians hand picked the best optical units for the Dual Range, for instance here:<br> http://theonlinephotographer.typepad.com/the_online_photographer/2010/05/ebay-treasures-the-7element-summicron.html<br> But, I have no idea where this story comes from or if it is true.<br> David</p>

<p>There is, in principle, a way to do this without damaging the lens at all. The trick is to find a compatible focusing mount from a "rigid" mount lens of the same era, and then just transfer the optical element (which screws out of the focusing mount) to the other focusing mount. This is completely reversible. But, it is complicated by the fact that different optical elements had different focal lengths, which were matched to the focusing mounts that they were shipped with. My understanding is that the DR models all had the same focal length, so that only one version of the DR focusing mount was needed, but the rigid models had a range of focal lengths. So, you would need not only a rigid focusing mount, but one for the correct focal length. In the past, I have entertained trying to find one, just to have a lighter weight lens on my M3. I imagine that it would take a lot of looking to find a lonely rigid mount, especially of the correct focal length.</p> <p>David</p>

<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>

<p>I have the Mamiya 7ii polarizer. The important point to be aware of is that it does not mount to the lens using the filter threads. Instead, it mounts using the bayonet tabs used for lens hoods. I don't know anything about the Mamiya 6 lenses, but I would not assume that the polarizer for the 7 will fit these lenses. They might, but might very well not.<br> David</p>