THE EPSON V750 / V700 SCANNER
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- The Epson V750/V700 are dual optics, fixed focus flatbed scanners capable of scanning all format up to 8x10.
- These scanners have undergone considerable improvements in resolution and dynamic range and for medium and large format rival drum scanners.
- The software included does not restrict the scanning area to that of the holder but can be adjusted to awhatever size is wished.
- The V750 Pro is supplied with a fluid mount tray, unique in the industry. The inclusion of a fluid mounting tray recognizes fluid scanning as the best medium for delivering high
quality scans. Epson intended to position this scanner as a substitute for drum scanners in the larger formats.
- The fluid mount tray supplied however can't withstand scanning fluids, and with the film on top of the glass, it subjects the image-forming-light to the additional refraction of 2.5 mm
thick glass. What the image gains by fluid scanning, it loses to glass refraction.
- In addition, the focus plane with the film placed on top of the glass is elevated to 3mm, higher than the optimum plane of focus for these scanners which is around .5 mm.
This and several other compromises, has led professional photographers and archivists to replace the tray with ScanScience system.
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Wet Mounting or fluid scanning has the potential for greatly improving image quality but it can be
undermined by refraction if additional glass is placed between the film and the sensors. ScanSceince
avoids additional refraction by placing the film under the fluid mounting plate (not above it as with the
Epson adapter). The ScanScience Pro kit uses an optical scanning plate just 1 mm thick, -as thick as a
microscope slide.
Referring to the figures below:
FIG. 1 - With Epson fluid mounting tray, the image forming light travels through a total of 4 mm of glass,
2mm for the fluid mounting adapter and 2 mm for the glassbed, before reaching the sensors.
FIG. 2, 3 With the ScanScience Pro Kit, the image-forming light emerging from the film is NOT refracted
by the adapter's glass plate.
Fig. 3 shows that the film elevation can be adjusted by fractions of a mm. to match the optimum focus
plane of the scanner actual unit, which may differ from the nominal optimal
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The V750 / 700 Scanner Optimal Focus Plane. Calibration for Maximum Sharpness
- The Epson V750 / V700 has two fixed focus planes, one for smaller films that uses the high
resolution high pass optics. To access the high resolution optics you need Silverfast or Vuescan.
You can not use Epson Scan.
- A lower focus plane for larger films and opaque material, using the low pass optics.
- The scanner software switches from one to the other depending on the resolution called for.
- ScanScience kits for 4X5 and smaller film utilize the high pass optics. Kits for larger films such as
8x10 , utilize the low pass optics.
- The ScanScience kits aligns the film perfectly to the custom-sized glass for the format you order,
and the adapter automatically masks all the area around the film for maximum dynamic range
and Dmax.
- Scanners are known to vary their optimal plane of focus from the nominal spec. The ScanScience
TKK Pro kits facilitate precise adjustment of the plane of focus by allowing scans at above and
below optimum elevation. This approach also is used with other flatbed scanners. A typical
adjustment of elevation via calibrated shims is illustrated below.
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ADJUSTING ELEVATION WITH THE EPSON SCANNERS
With the Epson V750 / V700 scanners the adapter and shims provided allow
adjusting the elevation to 2.0, 2.2, 2.4, 2.5, 2.7 and 2.9 mm.
With the other Epson scanners the adapter and shims provided allow adjusting the
elevation to 0.5 0.7, 1.0, 1.2, 1.6 and 1.8. mm.
Turn Key Kits (TKK) and Supplemental Kits (SK) include a calibrated adapter which
together with the shims supplied are grouped to achieve optimum elevation and
sharpest focus. No screws to turn, or screw turns to keep track of. To adjust
elevation just shuffle the shims and run scans at varying elevations to find the
optimum elevation for sharpest focus for your scanner.
Once you find the optimum elevation, retain the shim combination by bonding them
with the double sided tape included with the kit and forget it. You will do all scans at
this elevation.
(Three scans with a plastic holder with a screw system would require 32 screws to
turn and keep track of; it is so laborious that most people don't do it and scan at
elevation that is not optimal)
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