strip-end-curl : Nikon Coolscan : fix ?

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Djon

SA 21 film strip transport does a credible job with flatness except at
ends of strips, where it's rarely acceptable.

Sometimes the best frame is at the end of a strip, therefore doomed to
unsharpness issues: bad luck or bad decision.

This problem differs with film stocks..is particularly bad with Fuji
color negs.

Curly Fuji seems not to be flattened with weight (eg not by pressing in
a book) or counter-curling (eg wound backward around a film cannister
for several days).

....Do you flatten color negatives successfully? How ? (heat? what temp
is safe?)

....Has anybody explored SA 21 modifications ?

....Would the FH 3 serve? I've read that it's useless. Would it be a
good candidate for machine shop modification?

IDEA: re-usable metal "slide mount" that would allow the strip film
to be used in Nikon's MA 20 slide holder. I've tested this with
butchered Plastimount...the idea might work.

A cut-down Omega aircraft aluminum negative carrier might do the trick,
but it'd want some kind of mini-latch mechanism (I don't like inserting
tape into the mechanism).

Would a MAGNETIZED (self-latching) 5cmX5cm (slide mount size) steel
negative carrier be a mechanical or electronic problem?
 
Djon said:
SA 21 film strip transport does a credible job with flatness except at
ends of strips, where it's rarely acceptable.

Sometimes the best frame is at the end of a strip, therefore doomed to
unsharpness issues: bad luck or bad decision.

This problem differs with film stocks..is particularly bad with Fuji
color negs.

Curly Fuji seems not to be flattened with weight (eg not by pressing in
a book) or counter-curling (eg wound backward around a film cannister
for several days).

...Do you flatten color negatives successfully? How ? (heat? what temp
is safe?)
Click to expand...

Wash them in cool water and then dry the negative hanging on a line by
clothes pins weighted on the bottom with more clothes pins (plastic is
best). You can add an ounce or two fishing weights to the bottom of the film
if you wish.

A hair dryer at medium heat is OK if you keep the hair dryer moving.
 
CSM1 said:
Wash them in cool water and then dry the negative hanging on a line by
clothes pins weighted on the bottom with more clothes pins (plastic is
best). You can add an ounce or two fishing weights to the bottom of the film
if you wish.

A hair dryer at medium heat is OK if you keep the hair dryer moving.
Click to expand...
Yes, that works fine, but you need to add a drop of Wetting Agent to the
water, and / or squeegee the film, otherwise you might well get drying marks
where droplets have gathered at the lower end.

If that is the Plastic and Metal Film Strip Holder, it does work, but
getting the Strips of Slightly Curly Film into it, is a job for someone with
endless patience and extremely good co-ordination.

Normal plastic GePe Slide mounts work fine, but that means cutting the film
strips into Single Frames.

All of the above is one of the reasons I changed to the Minolta 5400, which
has excellent and easy to use Film Strip Carriers.

Roy G
 
Minolta's carriers require a tremendous amount of fiddling around.
They're inferior copies of the Polaroid carrier.

Nikon's standard strip film carrier is far better (flatter) except at
ends of frames, where it's similar to Minolta.

If Minolta cared about quality they would have made those carriers with
aluminum, and they would have shot whoever designed the mechanism in
the junk replacement model, 5400II (I've owned two).

IMO (subjective) Nikon's autofocus is more accurate than Minolta's, and
although Minolta's goofy manual focus knob might be entertaining, it's
not as accurate as Nikon's system. In any case, Nikon's maximum scan
time is 2.5 minutes, compared to comparable 8 minutes for Minolta.

Unless one can accept slow scans due to preference for the diffuser,
rather than doing the same thing digitally, the one credible argument
for Minolta is B&W film without Ice, which Minolta scans 15 seconds
quicker than the slowest Nikon.
 
TENTATIVE ANSWER>> I've ordered the Nikon FH3 carrier, which readily
accepts anti-newton glass.

That should resolve the flatness issue entirely, if reports from
seemingly-demanding users prove correct.

Custom anti-newton glass carriers also give Nikon 8000/9000 and various
flatbeds perfectly flat film.

Minolta 5400 could easily be retrofitted with decent film carriers...I
considered building them, but my experience with 5400II convinced me it
would also be discontinued..all it'd take would be a simple machine
shop and some aircraft aluminum, anti-newton glass optional. Nobody
would accept plastic carriers on their enlarger, so it's amazing that
we do accept plastic in scanners. Nikon's carrier is, like the carrier
I'd have made for Minolta, partially plastic and partially aluminum.
 
Minolta 5400 could easily be retrofitted with decent film carriers...I
Click to expand...

I really don't think a retrofit is needed. I have no problems with the
holders, apart from one instance of a fragile latch tab breaking, on
the slide holder. I have repared that, and have 2 replacement holders
now, which I use, in the main. No further breakage.

The holder designs, both slide and strip, are perfectly adequate, and
easy to use, John. My 2 cents.
 
Mendel, you're the 5400 guru, all I have is bad memories of short
experiences with 5400II (same carriers however).

Nikon's standard strip transport, SA21, doesn't use a
minolta/enlarger-style carrier...that Nikon device's only shortcomings
are 1) end frame curvature/focus problem, per my first post here 2)
learning curve Vs frameline alignment with Vuescan (easier, fully
automatic with Nikonscan) 3) occasional corner Vs center sharpness
issue due to depth of field Vs "bellied" or curved slides in mounts.
These would all be issues with an optical enlarger unless the enlarger
accepted film carriers that solve flatness issues: anti-newton glass or
special mechanical devices, such as Beseler's Negaflat, which grabs
film from the sides and pulls it flat.

While Minolta's carrier, a copy of Polaroid's, does work just as well
as typical enlarger carriers, it doesn't begin to work as well as those
advanced flatness carriers, and it would have been easy for Minolta to
produce and sell such advanced carriers if they wanted to deliver a
product that did the rest of their system justice. Beseler did it,
Durst did it, Omega did it, with their enlargers, it ain't rocket
science. Nikon's accessory FA3 carrier may move in the right direction
and, apparently, it can accept anti-newton glass. Before I modify mine
with glass I want to see if a mechanical modification would serve my
purpose as well...something to apply additional pressure to three sides
of end frames, and perhaps something movable to grip/flatten the forth
side, the very end of the strip.
 
Djon said:
Mendel, you're the 5400 guru, all I have is bad memories of short
experiences with 5400II (same carriers however).

Nikon's standard strip transport, SA21, doesn't use a
minolta/enlarger-style carrier...that Nikon device's only shortcomings
are 1) end frame curvature/focus problem, per my first post here 2)
learning curve Vs frameline alignment with Vuescan (easier, fully
automatic with Nikonscan) 3) occasional corner Vs center sharpness
issue due to depth of field Vs "bellied" or curved slides in mounts.
These would all be issues with an optical enlarger unless the enlarger
accepted film carriers that solve flatness issues: anti-newton glass or
special mechanical devices, such as Beseler's Negaflat, which grabs
film from the sides and pulls it flat.

While Minolta's carrier, a copy of Polaroid's, does work just as well
as typical enlarger carriers, it doesn't begin to work as well as those
advanced flatness carriers, and it would have been easy for Minolta to
produce and sell such advanced carriers if they wanted to deliver a
product that did the rest of their system justice. Beseler did it,
Durst did it, Omega did it, with their enlargers, it ain't rocket
science. Nikon's accessory FA3 carrier may move in the right direction
and, apparently, it can accept anti-newton glass. Before I modify mine
with glass I want to see if a mechanical modification would serve my
purpose as well...something to apply additional pressure to three sides
of end frames, and perhaps something movable to grip/flatten the forth
side, the very end of the strip.
Click to expand...

I don't think we should *have* to perform miracles in the film
flattening department. The engineers behind both Minolta and Nikon
scanners were shortsighted (pun fully intended) in their anticipation
of depth of focus requirements. The 5400 is worst of the two offenders,
in my slide exchange experience with a Coolscan 5000 user. I'm sure
increasing depth of focus on the scanners would be expensive, likely
involving longer scan times and/or better lens. So they decided against
this, and here we are.
 
I don't think we should *have* to perform miracles in the film
flattening department. The engineers behind both Minolta and Nikon
scanners were shortsighted (pun fully intended) in their anticipation
of depth of focus requirements. The 5400 is worst of the two offenders,
in my slide exchange experience with a Coolscan 5000 user. I'm sure
increasing depth of focus on the scanners would be expensive, likely
involving longer scan times and/or better lens. So they decided against
this, and here we are.
Click to expand...

Suppose that you want to reduce losses due to diffraction to 90% (MTF).
So we get 5400 dpi, which is 106 lp/mm. (I took the OTF equation from
Norman Koren's tutorials). We then get s = 0.000555 * N * 106 = 0.07.
(OTF(0.07) = 0.91). The 0.000555 is the wave length of green light.
That gives the aperture number N = 0.07 / (0.000555 * 106) = 1.19.

So, basically, you need an f/1.2 lens to avoid reduced sharpness from
diffraction. Obviously, an f/1.2 lens is not going to result in a large
depth of field.
 
SNIP
The 5400 is worst of the two offenders, in my slide exchange
experience with a Coolscan 5000 user.
Click to expand...

Is it? How did you arrive at that conclusion?

To me it seems non-intuitive to compare at native resolution, because
the 5400 creates 35% larger image dimensions. There may also have been
differences in placing the focus position.

Bart
 
I've failed to find again the Japanese graphs that compare optical
resolution ( lpm ...lines per mm) Vs ppi resolution of Nikon (V? 5000?)
and Minolta 5400 (I ? II?). The graphs depicted larger Minolta file
size for same lpm resolution, ie same detail/different file size. These
English/Japanese labeled graphs were easy to understand..Japanese
commentary was not.

In my own experience with 5400II and Nikon V, the scan times with Ice
were identical, 2.5minutes. As well, my prints from same negative
appeared identically grain sharp, cropped to full 8.5X11. There were
slight color and highlight/shadow rendition differences, neither
superior.

That Minolta does produce a bigger file is good for marketing, as would
have been the diffuser, if they continued to use it. Nikon's film
handling and reliability are are not advertised. Meaningful ways to
compare physical quality of these machines without buying both (as I
did) are by mass weight, case design (plastic or metal), ventillation
arrangement, and by opening case and looking inside Minolta (2 screws)
and Nikon (9 screws). Focus technique seems a matter of personal
preference...both are fine. I think Minolta's application was
better-designed, perhaps especially with B&W, but I'd use Vuescan
either way. Nikon's Ice may have advantages, but again I use Vuescan's
infared, which is complex but seems perfect.
 
Djon ([email protected]) wrote in @g43g2000cwa.googlegroups.com:
Meaningful ways to
compare physical quality of these machines without buying both (as I
did) are by mass weight, case design (plastic or metal), ventillation
arrangement, and by opening case and looking inside Minolta (2 screws)
and Nikon (9 screws).
Click to expand...

I understand all except "looking inside": how do you manage to look inside
a machine by unscrewing a number of screws without actually buying the
machine first?
 
Bart said:
SNIP

Is it? How did you arrive at that conclusion?

To me it seems non-intuitive to compare at native resolution, because
the 5400 creates 35% larger image dimensions. There may also have been
differences in placing the focus position.
Click to expand...

All valid points. I agree our test was not that good at eliminating
variables. Both of us just took our best crack at it. At least the
slide was in the same mount, for both scans.

Comparing the results: the centers of both scans had comparably crisp
grain. However, on the Nikon scan the crisp grain held a lot further
out towards the edge, compared to the 5400. I did like the overall
quality of my 5400 scan better tho, particularly the color renditions
in deep shadow. Again, that could be due to Nikon exposure settings.
 
SNIP
Comparing the results: the centers of both scans had comparably
crisp grain.
Click to expand...

Yes that is usually a good indicator, but one should also consider the
larger magnification at scan time, thus leading to lower output
magnification. It may be easier to see at 100% zoom on screen, it may
be less visible in final output. That's all.

Bart
 
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