My attention has recently returned to scanning some of the many old slides and negatives I have, archived in plastic and paper sleeves and Kodak slide mounts.
I was vaguely aware that slide mounts would crop a small margin around the frame, but I'd never taken a ruler to a Kodak slide mount and measured the opening. I'd had no reason to, until I got suspicious that some of the shots I'd taken many years ago, after scanning on my Nikon 8000ED, seemed to contravene even a basic sense (I won't use rules) of composition that I would have been aware of in those days, like not chopping off the tips of someone's fingers.
I was quite shocked to discover that all these old Kodak slide mounts reduce the 24x36mm format of 35mm to around 22x33mm. Well, perhaps that's not too bad if the slide is perfectly centred in the mount. One and a half mm off each end of the width and just 1mm off each end of the height might be no big deal. But, I presume the whole purpose of this cropping is to allow for error in the automatic mounting process. I have some slides that have been shifted as much as 3mm or more to one side in the mounting process.
I now feel obliged to remove every slide from its mount before scanning and carefully position it in the Nikon negative holder which doesn't appear to crop any part of the image (give or take 1/4 of an mm).
A preferrable alternative would be to replace the mount with another type of mount that doesn't crop the image. I haven't found such a mount yet.
Yet another alternative, is to use my Epson 4990 flatbed which comes with a negative holder which accommodates 4 strips of 6 negatives (or positives) with no divisions along the short edge, and the width is marginally greater than 24mm.
I'm still trying to determine if my Nikon 8000ED can produce superior results to this (apparently) extraordinary good value flatbed. The fact that I'm having difficulty in arriving at a definite conclusion in this regard might be interpreted by some that I simply don't know what I'm doing. And that might well be the case
The problem (oops!, issue) is that it's difficult to separate the performance of the hardware from the performance of the software. The Nikon software allows use of a 'scanner RGB profile' which I find produces better results than scanning 'into' any of the offered colour spaces (ARGB, Wide Gamut RGB etc). But, regardless of this factor, Nikonscan cannot use ICE satisfactorily with Kodachrome. There's a double edge. Vuescan, however, can
use its equivalent of ICE on Kodachrome, producing superior results.
Vuescan with the Epson 4990 is as bad as Nikonscan in this regard. Back to double edges or similar; in fact occasionally green edges. But Silverfast SE, which is packaged with the 4990, is superior to Vuescan in this respect and produces results, with the 'difficult' slides I've tried so far, that are very similar to what I achieved on the 8000ED. It's serious pixel-peeping to tell the difference in terms of resolution and shadow noise.
One major advantage of Vuescan is that it offers the option of digital blending. I guess most of us by now have heard of this technique of increasing the dynamic range of digital cameras by taking 2 or more different exposures of a scene and blending the results in a manner which extracts all the relevant detail from both (or all) shots.
Vuescan can do something similar when you 'photograph' your slide in your scanner. In fact, the scanner, I would have thought, lends itself to this technology. You have either a stationary target and moving scan light, or a staionary scan light and moving target. In either case, the stage is ideal for double (or triple) passes of varying exposure.
Any concern that the Dmax of the 4990 might not be quite as great as that of the 8000ED becomes irrelevant. 4.00 is very impressive anyway.
Absolute resolution is not something I've had time to test conclusively yet, but I'm going to search for some shots I took a few years ago with my Minolta 50/1.4. So far, resolution seems on a par with the Nikon 8000ED, give or take a small margin. Since the Nikon 8000ED was a really expensive item for me, the purchase of which was difficult to justify at the time, you might think I should have a personal bias to demonstrating the superiority of the Nikon. Not at all