Okay... Just had one of those "Ah-hah!" moments. I was comparing scanners today at my local photo store -- Epson 4990, MT i900 and MT i800.
First off, the Epson was fastest, the i800 sharpest by a touch and slowest by like 3x, and the i900 the softest and slower than the Epson. The "new" holder on the i800 is no great shakes. You need four hands to hold your tranny in place while you lock it to avoind crinkling the tranny. Add the incredibly slow scan times and this is one scanner to avoid if you plan on scanning 4x5 at any significant resolution. The i900 was softer and slower than the Epson and had a weird halo on high-contrast edges. (So guess which scanner I brought home...)
Anyway, back to my stupid... I was testing these scanners out on a piece of 4x5 tranny. I used them all and came back to my office to compre their results to my aging Epson 3200 pro -- a scanner I've had a love/hate relationship with for the past few years. Great for casual reflective scans, marginal for tranny and really sucked for 4x5 since the holder was crap and I always got Newton rings. Here's when the "Ah-hah" hit. I am SURE somebody else has realized this and I simply missed the memo... But in my defense I have been a sort of 3-year hiatus from the 4x5 film world.
But now I'm back. So in comparing my 3200 scans to the above breed, it's age is clearly showing. Even with Silverfast, the best I could manage was still softer and had less DR than any of the above newer scanners and itr is slow too. No surprise. As I put my test tranny in the crappy holder I asked myself why a company like Epson could not design a better holder -- FTR, the holder for the 4990 is essentially unchanged from the 3200, only there are 2 slots so you can scan 2 4x5's at once. Wow.
The Epson manual clearly states to load the base side down with the tranny inverted left/right. Base side down with 4x5 means the smooth shiny side of the tranny -- also the side that bows out -- can also easily contact the glass surface of the scanner and generate Newton rings. Dang, no free lunch... No problem, I placed little shims on my 3200 holder to hold the bowing tranny off the glass, I could do the same again with the 4990. Or I could buy that guy's fancy holders...
That's when I decided WTF, why not load the tranny emulsion side down? Now the tranny bows away from the glass the way it should and then gravity works for me, drawing the center of the tranny almost perfectly flat, yet still leaving an air-gap above the glass. Sure the image would be reversed, but a mirror-flip in CS is a piece of cake. So I tried it. Result? Best scan I ever got off my 3200, period! Ran back to camera store with test tranny, loaded it upsidedown in the 4990 holder and scanned. WOWSERS! WAYYYYYY sharper than the first set of scans with the tranny loaded -- errr -- correctly... So I came home with the 4990.
Okay, certainly somebody is going to tell me this is old news and ask where the ____ have I been...
Feeling stupid in Silicon Valley,