v700 snippets, reposted

[Raphael Bustin]

The snippets page has been updated with two new V700 scans.

Alan Bridgewater has re-scanned his 645 Reala negative
using EpsonScan, and with more attention to focus and color.

<http://www.terrapinphoto.com/jmdavis/>

about 2/3 of the way down the page.



rafe b
www.terrapinphoto.com

 

[Ernst Dinkla]

The snippets page has been updated with two new V700 scans.

Alan Bridgewater has re-scanned his 645 Reala negative
using EpsonScan, and with more attention to focus and color.

<http://www.terrapinphoto.com/jmdavis/>

about 2/3 of the way down the page.



rafe b
www.terrapinphoto.com

Rafe, Alan,

Much better, especially with the USM. Not LS8000 quality but
close enough for a 4x5 - 8x10 scanner. Wonder what the V750
will do better.

Is the 5 mm in the file name an indication of the focus height
? That would be much above the range Epson anticipated.


Ernst

--

--
Ernst Dinkla


www.pigment-print.com
( unvollendet )

 

[Alan Bridgewater]

Rafe, Alan,

Much better, especially with the USM. Not LS8000 quality but close
enough for a 4x5 - 8x10 scanner. Wonder what the V750 will do better.

Is the 5 mm in the file name an indication of the focus height ? That
would be much above the range Epson anticipated.

The height was 4.5mm, hence 4_5 in the filename (full stops not
allowed!). That's a millimetre above the maximum expected by Epson. They
clearly anticipated a variation in focus distance as evidenced by the
supplying of variable height spacers.

I went up to 5.0mm but image quality was not as good. That's distance
from the glass to the emulsion, which was facing downwards, not up as
the instructions suggest.

Scanning with the emulsion facing up gave a slightly degraded image. I
assume this was because of diffusion on passing through the film base,
although of course, the emulsion is now further away from the sensor by
the thickness of the film and may be beyond the useful depth of field.

Alan

 

[Ernst Dinkla]

The height was 4.5mm, hence 4_5 in the filename (full stops not
allowed!). That's a millimetre above the maximum expected by Epson. They
clearly anticipated a variation in focus distance as evidenced by the
supplying of variable height spacers.

I went up to 5.0mm but image quality was not as good. That's distance
from the glass to the emulsion, which was facing downwards, not up as
the instructions suggest.

Scanning with the emulsion facing up gave a slightly degraded image. I
assume this was because of diffusion on passing through the film base,
although of course, the emulsion is now further away from the sensor by
the thickness of the film and may be beyond the useful depth of field.

Alan

Alan,

Could be beyond the useful depth of field but I doubt it would
degrade much by the 0.13 mm shift. If the film has a curl the
height shift could be much more in a glassless carrier. I
guess that may have been the case more than the film base
light transmission. Not that the last should be ignored.
There's a lot more going on in my opinion. Not just focus but
light transmission with the curve upwards or downwards of the
film + emulsion, the difference in surface gloss between
emulsion side and the base side, the relative translucency
versus transparency of base + emulsion etc. That's why I
return to wet mounting as a solution for more consistency in
scanning: repeatable planarity for focus, for total area, for
transmission + consistent surfaces from one frame/film to another.

Nice to see a first evidence that the 2,5 - 3,5 mm focus range
of Epson may not be the range in practice. I already expressed
my doubts that all scanners would fall within range. What did
you use to get at 4.5 mm ? Could it be that the film actually
bulges to say 3,5 mm in the center ?


Ernst

--

--
Ernst Dinkla


www.pigment-print.com
( unvollendet )

 

[Alan Bridgewater]

Nice to see a first evidence that the 2,5 - 3,5 mm focus range of Epson
may not be the range in practice. I already expressed my doubts that
all scanners would fall within range. What did you use to get at 4.5 mm
?

I used two sheets of 0.5mm card to support the film holder (spacers set
at 3.5mm), with holes cut in them.

Could it be that the film actually bulges to say 3,5 mm in the center ?

It doesn't look to me as though there is any sag, certainly not to the
extent of 1mm.

Visually, the film looks quite flat in the holder. However, reflections
of objects seen in the glossy side of the film show some distortion, so
it's obviously not perfectly flat.

Also, on negs I've scanned today, there's no discernible change in the
definition of the grain on going across from one side to the other; I
would expect to see some blurring in the centre if the film was bowed.

I have seen that effect on some monochrome film that I scanned; it was
quite clearly bowed. Even that has improved now though. I think I
scanned the film too soon after processing; it felt dry to the touch but
there must still have been some moisture absorbed in the gelatine. After
a couple of days the film completely lost its curvature and could be
clamped flat in the film holder.

Alan

 

[Ernst Dinkla]

I used two sheets of 0.5mm card to support the film holder (spacers set
at 3.5mm), with holes cut in them.


It doesn't look to me as though there is any sag, certainly not to the
extent of 1mm.

Visually, the film looks quite flat in the holder. However, reflections
of objects seen in the glossy side of the film show some distortion, so
it's obviously not perfectly flat.

Also, on negs I've scanned today, there's no discernible change in the
definition of the grain on going across from one side to the other; I
would expect to see some blurring in the centre if the film was bowed.

I have seen that effect on some monochrome film that I scanned; it was
quite clearly bowed. Even that has improved now though. I think I
scanned the film too soon after processing; it felt dry to the touch but
there must still have been some moisture absorbed in the gelatine. After
a couple of days the film completely lost its curvature and could be
clamped flat in the film holder.

Alan

Alan,

Alright, then it is the Epson manufacturing tolerance again.
It didn't improve with the V700 and it probably is more of a
nuisance now as I expect the DOF to be more limited in the
optical system compared to the older models. Many users will
now expect that the three choices of focus correction provided
by Epson are covering the range and settle for the one that's
closest to the real focus. A pity as that doesn't deliver the
best quality on the scanners that are more off. In a way worse
than with the old models where nobody knew what the focus
shift could be and you had no expectation of its range.

Ernst
--

--
Ernst Dinkla


www.pigment-print.com
( unvollendet )

 

[Alan Bridgewater]

Alright, then it is the Epson manufacturing tolerance again. It didn't
improve with the V700 and it probably is more of a nuisance now as I
expect the DOF to be more limited in the optical system compared to the
older models. Many users will now expect that the three choices of
focus correction provided by Epson are covering the range and settle
for the one that's closest to the real focus. A pity as that doesn't
deliver the best quality on the scanners that are more off. In a way
worse than with the old models where nobody knew what the focus shift
could be and you had no expectation of its range.

Ernst,

At least they acknowledge that there may be a need to adjust the focus
plane.

My previous scanner was a CanoScan 8000F. It gave sharp reflective scans
of material placed on the glass and I wondered if the DOF was sufficient
to cover film in the film holder, which held the film 2 or 3mm away from
the glass. It wasn't

I ended up abandoning the film holder for negatives and scanning
directly on the platen surface, under a glass plate to maintain
flatness. Scans made this way were significantly sharper than scans made
using the film holder, but then Newton's rings caused endless problems.

It seems to me that flatbed scanners are all going to suffer from the
same problem; they have to have the plane of focus optimised for either
film in a holder above the glass, or material placed directly on the
glass. The DOF is never going to be enough to cover both.

The V700 does shift focus when scanning large format material without
the film holder; the lens that's used for this purpose definitely seems
focussed on the glass surface rather than 3mm or so above.

Alan

 

[HvdV]

Alright, then it is the Epson manufacturing tolerance again. It didn't
improve with the V700 and it probably is more of a nuisance now as I
expect the DOF to be more limited in the optical system compared to the
older models. Many users will now expect that the three choices of focus
correction provided by Epson are covering the range and settle for the
one that's closest to the real focus. A pity as that doesn't deliver the
best quality on the scanners that are more off. In a way worse than with
the old models where nobody knew what the focus shift could be and you
had no expectation of its range.

I've never opened a flatbed scanner, but it would seem reasonable that if the
lenses have appreciable focal length variation then there is a calibration
screw near the lens to factory-tune the focus. If so, then one could improve
calibration with that instead of pieces of cardboard. Anyone looked inside a
V700 yet?

-- Hans

 

[J. L. Jones]

Alan,

Alright, then it is the Epson manufacturing tolerance again.
It didn't improve with the V700 and it probably is more of a
nuisance now as I expect the DOF to be more limited in the
optical system compared to the older models. Many users will
now expect that the three choices of focus correction provided
by Epson are covering the range and settle for the one that's
closest to the real focus. A pity as that doesn't deliver the
best quality on the scanners that are more off. In a way worse
than with the old models where nobody knew what the focus
shift could be and you had no expectation of its range.

Ernst

I've got four questions:

1. What's USM?

2. Are any of these V700 tests made using wet mounting?
(Maybe that's what USM is.)

3. Is it possible that 4990 sharpness could be increased by
using spacers? Has anyone explored this?

4. I gather all the test scans being examined were from 120
film. Has anyone made any 4x5 scans with the v700 to compare
with the 4990? I bought the 4990 because I can't afford a
"real" 4x5 film scanner. I could spring for a v700, though.

Thanks,

J. L. Jones

 

[Roger S.]

Quote:

"2. Are any of these V700 tests made using wet mounting?
(Maybe that's what USM is.) "

USM is unsharp masking, a sharpening technique done after the scan was
completed.
It doesn't seem like anyone has been wet mounting the V700 in the above
posts.

 

[Alan Bridgewater]

Quote:

"2. Are any of these V700 tests made using wet mounting?
(Maybe that's what USM is.) "

USM is unsharp masking, a sharpening technique done after the scan was
completed.
It doesn't seem like anyone has been wet mounting the V700 in the above
posts.

I haven't been using wet mounting, just the standard film holder.

Wet mounting involves clamping the film to the scanner bed with a film
of fluid between the contact surfaces. This ensures film flatness and
minimises the effect of scratches on the film surface as well as, I
believe, minimising the effects of grain.

Wet mounting kit is available that can be used on either the v700 or the
v750.

If I've got anything wrong here, or left something out, I'm sure that
someone else will clarify.

Alan

 

[Bjorn A. Payne Diaz]

Do you have more details on the wet mounting kit of the V700?

I'm considering a 700, but kind of waiting for the 750 reviews. I'm
interested in wet mount scans.

Jay Wenner

 

[-]

I'm considering a 700, but kind of waiting for the 750 reviews. I'm

interested in wet mount scans.

You might be interested in the review on the 750 that has just started at
www.photo-i.co.uk . If you will be buying from the U.S., the 750 is
supposed to include the tray. You will have to buy your own fluid and
supplies on your own. The tray may be an additional cost option for 750's
that are sold in some other countries.

Doug

 

[Ernst Dinkla]

I've never opened a flatbed scanner, but it would seem reasonable that
if the lenses have appreciable focal length variation then there is a
calibration screw near the lens to factory-tune the focus. If so, then
one could improve calibration with that instead of pieces of cardboard.
Anyone looked inside a V700 yet?

-- Hans

Typical setups have a plastic molding with a U shaped bed that
holds the cylinder shape of the total lens while a flat metal
spring clamps the lens assembly in that bed. The lens can
still be shifted for focusing over the length of that bed in
the manufacturing process and is then fixed with some glue. It
will be difficult to get near the lens anyway as it halfway
the folded path of 4-5 mirrors between the scan bed and the
linear sensors.

With the V700 and the V750-M there's another aspect. The wide
lens that does the scan bed for A4 reflective and 8X10 film at
4800 SPI will be focused just above the glass of the scan bed,
most likely 0.5 mm above to take care of some manufacturing
tolerances and the expansion of the scanner housing when it
gets warmer after some scans. At least that's something I
would think off if I was an Epson designer. That should ensure
that there's no chance of having the focus way below the glass
+ it takes care of having the focus closer on the film
emulsion in a film scan. For reflective scanning at 600 SPI
the right focus is far less important. I think Epson's
priority lies in getting that focus more or less correct for
the 8x10 film. The two lenses may have had a focus alignment
to one another on a bench before the assembly of the total
optical carriage (sensor, mirrors, lens) is placed in the
scanner. The height adapters should bring the film holders at
the right focus for the 6400 SPI lens, that's what the user
adds to the job.

http://www.i-love-epson.co.jp/products/colorio/scanner/gtx900/technology.htm

Ernst

--

--
Ernst Dinkla


www.pigment-print.com
( unvollendet )

 

[Ernst Dinkla]

Wet mounting involves clamping the film to the scanner bed with a film
of fluid between the contact surfaces. This ensures film flatness and
minimises the effect of scratches on the film surface as well as, I
believe, minimising the effects of grain.

It is in most cases better to wet mount the film to an extra
glass sheet at a separate table and after that have the film
hanging underneath that glass at the right focus on the
flatbed scanner. Less mess on the scanner and the film at
right spot while the light gets through the glass above it and
no extra glass is in the optical path itself.

Ernst

--

--
Ernst Dinkla


www.pigment-print.com
( unvollendet )

 

[Bjorn A. Payne Diaz]

Ernst,

Interesting idea. I assume a "regular" sheet of glass can be used
(don't need an antinewton glass), and then shimmed to get the correct
plane of focus off the scanner bed?

The partial review of the 750 is already interesting. Artifacts? Wow.
Anyway, it seems (and I'm just guessing) that the resolution between
the 700 and 750 should be very similar, and that the optical
improvements were geared to help scan speed more than resolution.
Without knowing anything about the 750, I assumed the big factor for
the extra cost would be in the wet mount kit. And you know what happens
when you assume.

Jay Wenner