I'm the OP. I only work with 8x10 film. Let me share/repeat some experiences/findings/intentions:
Plane of focus: This is a problem with the V750. I got my first one replaced by Epson because they could not repair the following problem: The plane of focus was always 3 mm above the scanner glass. But for 8x10 film and reflective media it should be on the scanner glass. Only for smaller film a different optical system should work with a plane of focus 3 mm above the scanner glass.
I have tested different V 750 scanners (4) with the same negative and also compared with the Creo Eversmart II (2540 dpi optical resolution). The result: The Creo has a small resolution advantage and no newton ring problems. But a big workflow disadvantage.
Disadvantages of Creo: scan duration, max. file size 1GB, you can't stitch because two scans with identical settings are always slightly different.
Resolution: My "feeling" is that the V750 true resolution is around 1900-2100 dpi (for 8x10 scans, smaller formats can make use of the other/better optical system in the scanner). The Creo might have real 2540 dpi but if you scan twice the scans are not identical - but all are better than V750.
Newton rings: The Epson shows them very much if the negative is thin. The Creo virtually shows no newton rings and uses anti newton glass above and below the negative. The top glass is hold by springs. If you close the scanner the top glass pushes the negative softly to the bottom glass. In addition the bottom glass feels always warm so it evaporates moisture in the negative. That reduces also the possibility of newton rings. You just wait a few seconds before you close the scanner so that the moisture can escape from under the negative.
With these experiences I want to pimp the V750:
1. Step: I "warm up" the negative outside the scanner because I don't know how the Epson would react if I heat up its interiors.
2. Step: I use mainly HP5Plus and put the emulsion side on the scanner glass. Then I put an anti newton glass on top of the negative. To limit the pressure I use "spacers" outside of the negative (cut from film that is slightly thicker than HP5Plus). The glass lies more on the spacers than on the negative but prevents the negative from curling.
3. Step: Replace the bottom scanner glass with an anti newton glass.
4. Step: Built in a possibility to micro adjust the bottom scanner glass for optimal focus.
Any help and thoughts are appreciated.
File size with the Eversmart is issue of OS 9 operating system. It can be increased, Apple has a patch for this. However, I too have a problem in making two scans with identical setting using the Eversmart scanning application that are exactly alike in terms of density. But the scans merge fine with Photoshop, even though it may be necessary to do a bit of work to even the density before you flatten the file.
I have an Epson V700 and an Eversmart Pro, but should be no difference in resolution to the scanners you tested. I tested both with a high resolution chrome on glasss target (225 lp/mm). Most I could get with the V700, when using the film area guide which one would use for 8X10, was less than 1800 dpi. With the Eversmart Pro I get more than 3000 dpi. Quite a huge difference in my testing. BTW, the Creo Eversmart Pro and Pro II has real resolution of 3175 dpi, not 2540 dpi. If you did not see any difference in your testing it may be because the 8X10 negatives used in the testing did not carry any more than the equivalent of about 1800 dpi. This is very likely in my experience with 8X10 and larger negatives.
The Eversmart Pro/Pro 11 was not originally fitted with AN glass on top of the scanner bed, though it does have AN on the glass above the bed (over the negative). The original glass on the scanner bed has a coating similar to the coating on lenses, to reduce flare.
As I opined earlier in the thred, I believe there is a simpler and better solution for you than replacing the original glass of the Epson V700/V750 with AN glass. Just float a piece of glass above the bed, using shims to determine best focus, and fluid mount the negative to the botton of the glass. Or, if you do not want to fluid mount, use a piece of glass above the bed with an AN layer on top, and just place the negative on this surface. Both methods replicate the system of the BetterScanning holders, which gives optimum results in my experience with the Epson V700/V750 scanners.
I found I couldn't get above ~1650 ppi actual resolution with the "film area guide" setting compared to ~2350 ppi with the "film holder" setting on my best V700 (I have access to a large number of them in my lab). 1650 ppi with 8x10 is still A LOT of image.
I'm scanning my 8x10's now with an Epson 10,000XL as it has manual focus settings. I sandwich the negative between 2 sheets of anti-newton glass and scan at an actual 2400ppi. Makes for huge files.
Edit: Here we go...
The useable scanning area targets the more narrow field of view for the EpsonŽ V Series' second "high resolution" scanning lens.
Thus the scanning area is approximately 225 mm x 145 mm (8.85" x 5.71") for fluid mounting and slightly less at 215 mm x 145 mm (8.46" x 5.71") for dry mounting.
This is true. In order to scan a full 8X10 are you must choose film area guide, not film holder, and that decision automatically selects the lower resolution lens.
But that is true regardless of how you scan 8X10 film, whether directly on the scanner bed glass, or on a piece of glass floating over the scanner bed glass. So far as I know there is no way to scan a full 8X10 sheet with the higher resolution lens. Perhaps there is, but I don't know how.
Thanks for your insights on the v700 series and the limit of 5x7 for max resolution.
So with the Epson 10,000 XL, have you determined the max O.D. range? Can one scan for darks, mid-tones and then highlights and combine to expand the dynamic range or one does not have that control? Also do you find advantage to using wet-mounting with this scanner.
Lastly, given the $2400 cost, why didn't you go for a used high end scanner, say from Genesis?
I had a talk with the company where I bought the anti Newton glass. In the end I trusted their advice (http://www.kienzle-phototechnik.de/h...e_english.html). I left the glass in the scanner alone and put the film with the emulsion side on the scanner. Then I put an anti Newton glass on top of the film to hold it down. Now I get only Newton rings with thin negatives (HP5+). So far I can live with it. I only scan 8x10 inch HP5+ negatives.