A few questions about the Epson V750M Pro

[timbo10ca]

1) What is the maximum real dpi for scanning (beyond which there is no improvement in scan quality, just increased file size)? I've been using 4000dpi for my Nikon V ED, but the files are still quite manageable coming from 35mm film. A scan of a 5x7 sheet film in 16 bit greyscale at 4800 with the V750 gives a huge file of 1.4 GB- my computer can't handle this!

2) what is its true OD? (specs say 4.0 but I don't know if I believe it).

3) Are the Betterscanning sheet and roll film holders necessary if one was to use the included V750 Fluid Mount kit and only scan using fluid, not the film holders?

4) What is the recommended fluid for fluid mounting

5) is 3mm Mylar ok for fluid mounting, or should it be 1mm?

Thanks,
Tim

[Brian Ellis]

Since nobody else has answered - as I recall from the tests the late Ted Harris did that were published in View Camera a few years ago, the 700/750 is capable of resolving about half its stated capability, i.e. about 2000 dpi. I don't know about the rest of your questions, sorry.

[Steve Wadlington]

[QUOTE=timbo10ca;424652]1) What is the maximum real dpi for scanning

>I have a Epson 4990 which is simular. About max 1500-1800dpi.

2) what is its true OD? (specs say 4.0 but I don't know if I believe it).

>I have scanned a Stouffer step tablet 3.0D. The scanner will capture the range although there is roll off on the high end. I made a spreadsheet to correct to linear for density measurements.

3) Are the Betterscanning sheet and roll film holders necessary if one was to use the included V750 Fluid Mount kit and only scan using fluid, not the film holders?

>You will need to determine your optimum height. On the 4990, I scanned on the glass, 1.2mm up, 3.0mm up. On mine 1.2mm was best. I have a Betterscanning roll holder but don't like it. I use a mask cut from matteboard 1.2mm thick and a glass plate on top for wetmounting.

4) What is the recommended fluid for fluid mounting

>I use Aztec fluid.

5) is 3mm Mylar ok for fluid mounting, or should it be 1mm?

>I use Aztec mylar.

Steve

[Ed Richards]

One caveat - Ted did not run it at the highest rez, which engages the second optical system. I have not seen any of the LF reviewers do this, so it is unclear if it can do better than about 2000. (Not that 2000 is bad at all for a consumer scanner.)

The best review I found is here:

http://www.photo-i.co.uk/Reviews/int...750/page_1.htm

[timbo10ca]

One caveat - Ted did not run it at the highest rez, which engages the second optical system. I have not seen any of the LF reviewers do this, so it is unclear if it can do better than about 2000. (Not that 2000 is bad at all for a consumer scanner.)

The best review I found is here:

http://www.photo-i.co.uk/Reviews/int...750/page_1.htm

I thought this was a misnomer, and that both lenses could function as "high res". I thought that one lens was to scan on the glass and the other identical lens was to scan film in the holders, as they are fixed lenses working with 2 film positions. I figured that 6400dpi was high res, and scanning at 2000dpi wouldn't be considered high res, regardles of the lens in use. I'm not sure what this whole "high res' thing is all about, other than marketing.

[PenGun]

I thought this was a misnomer, and that both lenses could function as "high res". I thought that one lens was to scan on the glass and the other identical lens was to scan film in the holders, as they are fixed lenses working with 2 film positions. I figured that 6400dpi was high res, and scanning at 2000dpi wouldn't be considered high res, regardles of the lens in use. I'm not sure what this whole "high res' thing is all about, other than marketing.

The "low res" lens scans the entire area and is needed for 8x10, full scale suff.

The "hi res" lens scans about 5.7" down the center where the film holders place the 35mm, MF and 4x5 film.

[PenGun]

Got my V700. It is interesting that my machine is sharpest, 6400 dpi 35mm in the strip holder, with the feet off, at it's lowest position in other words. Others have found the highest setting is sharpest. It's obvious these machines need to be individually dialed in for optimum performance. I'm not sure even lower would not be sharper but that's enough for tonight's testing.

This with Vuescan in Linux.

[Peter De Smidt]

PenGun,

Try scanning with the emulsion directly on the scanning bed. Now flip the negative and scan with the base side down. Which looks best? This'll tell you whether the best position is on the bed or above the glass. If it's above the glass, then you'll need to check various heights. One my Canon, it was best with the emulsion .5mm above the bed.

[PenGun]

PenGun,

Try scanning with the emulsion directly on the scanning bed. Now flip the negative and scan with the base side down. Which looks best? This'll tell you whether the best position is on the bed or above the glass. If it's above the glass, then you'll need to check various heights. One my Canon, it was best with the emulsion .5mm above the bed.

I have just begun testing this puppy. I will find it's sweet spots and use them. Going to test in windose today.

AFAIKT the "low res" lens system focuses on the glass and the "hi res" lens focuses somewhere above it.

[Gene McCluney]

Various Microtek scanners have this low-res, hi-res feature, which scans the full size of the scanning area for "low-res" and then for "hi-res" switches to another lens (internally) and scans a smaller area on the scanning stage. My Microtek Artixscan 2500f will only scan 1/2 the area for "Double Optical Resolution" mode.