Flatbeds max out at 2000dpi for negs...??

Did I read it here recently that regardless of the claimed max resolution of
high end flatbed scanners ie. Epson 4870, that when scanning negs the max
resolution is 2000dpi because of some issue with the glass?? Is this true?
If so then it stands to reason that MF is the logical choice of format
because it's the largest format that can be scanned on a dedicated film
scanner. A bigger format than MF will have to be scanned on a flatbed
anyways right? So unless you're shooting in a very large format (6x9
inches) you won't gain anything by scanning on a flatbed. Am I right? If
so then it's one more reason for me to invest in a few choice lenses for my
rb67.
Ivan

"Ivan" wrote:

Did I read it here recently that regardless of the claimed max resolution
of
high end flatbed scanners ie. Epson 4870, that when scanning negs the max
resolution is 2000dpi because of some issue with the glass?? Is this
true?

The best example from the 4870 I've seen was somewhat worse (although less
grainy) than a 2800 dpi Nikon film scanner scan of the same slide. Neither
were as nice as what comes out of a dSLR _on a per-pixel basis_. If you want
pixels that look as good as dSLR pixels, you need to downsample your scans,
whatever scanner you use. (The reason for bringing up dSLRs, is that I want
a common standard for comparison.)

If so then it stands to reason that MF is the logical choice of format
because it's the largest format that can be scanned on a dedicated film
scanner. A bigger format than MF will have to be scanned on a flatbed
anyways right? So unless you're shooting in a very large format (6x9
inches) you won't gain anything by scanning on a flatbed. Am I right? If
so then it's one more reason for me to invest in a few choice lenses for
my
rb67.

My guess is that 4x5 scanned on a 4870 would look better than 6x7 scanned on
a Nikon 8000, but there may be problems scanning 4x5 on a 4870 in that (4800
x 4 x 4800 x 5) x 3 = 1382 MB, and it's hard to configure a PC to handle
that. A Mac with 4GB might work.

My assumption here is that scanning at 4800 dpi and downsampling to 2000 dpi
would look better than scanning at 2400 dpi and downsampling to 2000 dpi. I
don't own a 4870, so I don't know how much one loses scanning at a lower
resolution in the scanner. Usually, scanning at the highest native
resolution, denoise, sharpen lightly, and bicubic downsample results in a
better looking file than scanning at 1/2 the native resolution. Usually.

FWIW, I've heard conflicting reports of how good the 4870 is: some people
are happy, some people aren't. I was unhappy with the 2450, but that's
getting to be ancient history by now.

David J. Littleboy
Tokyo, Japan

"Ivan" wrote:

Did I read it here recently that regardless of the claimed max resolution
of
high end flatbed scanners ie. Epson 4870, that when scanning negs the max
resolution is 2000dpi because of some issue with the glass?? Is this
true?

The best example from the 4870 I've seen was somewhat worse (although less
grainy) than a 2800 dpi Nikon film scanner scan of the same slide. Neither
were as nice as what comes out of a dSLR _on a per-pixel basis_. If you want
pixels that look as good as dSLR pixels, you need to downsample your scans,
whatever scanner you use. (The reason for bringing up dSLRs, is that I want
a common standard for comparison.)

If so then it stands to reason that MF is the logical choice of format
because it's the largest format that can be scanned on a dedicated film
scanner. A bigger format than MF will have to be scanned on a flatbed
anyways right? So unless you're shooting in a very large format (6x9
inches) you won't gain anything by scanning on a flatbed. Am I right? If
so then it's one more reason for me to invest in a few choice lenses for
my
rb67.

My guess is that 4x5 scanned on a 4870 would look better than 6x7 scanned on
a Nikon 8000, but there may be problems scanning 4x5 on a 4870 in that (4800
x 4 x 4800 x 5) x 3 = 1382 MB, and it's hard to configure a PC to handle
that. A Mac with 4GB might work.

My assumption here is that scanning at 4800 dpi and downsampling to 2000 dpi
would look better than scanning at 2400 dpi and downsampling to 2000 dpi. I
don't own a 4870, so I don't know how much one loses scanning at a lower
resolution in the scanner. Usually, scanning at the highest native
resolution, denoise, sharpen lightly, and bicubic downsample results in a
better looking file than scanning at 1/2 the native resolution. Usually.

FWIW, I've heard conflicting reports of how good the 4870 is: some people
are happy, some people aren't. I was unhappy with the 2450, but that's
getting to be ancient history by now.

David J. Littleboy
Tokyo, Japan

Recently, Ivan posted:

Did I read it here recently that regardless of the claimed max
resolution of high end flatbed scanners ie. Epson 4870, that when
scanning negs the max resolution is 2000dpi because of some issue
with the glass??

It is so, but there are more issues than just the glass. The inability to
tightly control of the sensor movement also limits resolution.

Is this true? If so then it stands to reason that
MF is the logical choice of format because it's the largest format
that can be scanned on a dedicated film scanner.

Well, it's the largest format that can be scanned on consumer-level film
scanners.

A bigger format
than MF will have to be scanned on a flatbed anyways right?

Not necessarily.

So
unless you're shooting in a very large format (6x9 inches) you won't
gain anything by scanning on a flatbed. Am I right? If so then it's
one more reason for me to invest in a few choice lenses for my rb67.

I would think that the best reason to invest in "choice lenses" would be
to increase your shooting options. A lot depends on what you're trying to
accompish.

Neil

Recently, David J. Littleboy posted:

(The reason for bringing up dSLRs, is that I want a common standard
for comparison.)

(cough...) why not use drum scanners as a common standard for comparing
results from other kinds of scanners? At least the objectives would be
similar.

My guess is that 4x5 scanned on a 4870 would look better than 6x7
scanned on a Nikon 8000, but there may be problems scanning 4x5 on a
4870 in that (4800 x 4 x 4800 x 5) x 3 = 1382 MB, and it's hard to
configure a PC to handle that. A Mac with 4GB might work.

Oh? I haven't had any difficulty doing so for well over a decade. And,
until OS-X, virtual memory has always worked better on a PC. Such problems
with "large" scans were typically caused by the way that some scanner
drivers were written, especially so on consumer-level units. The better
scanners and software were (and still are) only limited by maximum OS file
sizes, not RAM.

My assumption here is that scanning at 4800 dpi and downsampling to
2000 dpi would look better than scanning at 2400 dpi and downsampling
to 2000 dpi.

Well, that flies in the face of accepted resampling practices and typical
algorithms (e.g. bicubic, etc.). The larger the step, the worse the
results.

Neil

Recently, David J. Littleboy posted:

(The reason for bringing up dSLRs, is that I want a common standard
for comparison.)

(cough...) why not use drum scanners as a common standard for comparing
results from other kinds of scanners? At least the objectives would be
similar.

My guess is that 4x5 scanned on a 4870 would look better than 6x7
scanned on a Nikon 8000, but there may be problems scanning 4x5 on a
4870 in that (4800 x 4 x 4800 x 5) x 3 = 1382 MB, and it's hard to
configure a PC to handle that. A Mac with 4GB might work.

Oh? I haven't had any difficulty doing so for well over a decade. And,
until OS-X, virtual memory has always worked better on a PC. Such problems
with "large" scans were typically caused by the way that some scanner
drivers were written, especially so on consumer-level units. The better
scanners and software were (and still are) only limited by maximum OS file
sizes, not RAM.

My assumption here is that scanning at 4800 dpi and downsampling to
2000 dpi would look better than scanning at 2400 dpi and downsampling
to 2000 dpi.

Well, that flies in the face of accepted resampling practices and typical
algorithms (e.g. bicubic, etc.). The larger the step, the worse the
results.

Neil

"David J. Littleboy" wrote in message
...

My guess is that 4x5 scanned on a 4870 would look better than 6x7 scanned
on
a Nikon 8000, but there may be problems scanning 4x5 on a 4870 in that
(4800
x 4 x 4800 x 5) x 3 = 1382 MB, and it's hard to configure a PC to handle
that. A Mac with 4GB might work.

A small technical aside: WindoZe XP can handle the same max-size application
of 1.7GB RAM as the Macintosh can. You can install 4gb but the application
cannot use more than 2 (irl 1.8) on either platform. Not yet, anyway.

"David J. Littleboy" wrote in message
...

My guess is that 4x5 scanned on a 4870 would look better than 6x7 scanned
on
a Nikon 8000, but there may be problems scanning 4x5 on a 4870 in that
(4800
x 4 x 4800 x 5) x 3 = 1382 MB, and it's hard to configure a PC to handle
that. A Mac with 4GB might work.

A small technical aside: WindoZe XP can handle the same max-size application
of 1.7GB RAM as the Macintosh can. You can install 4gb but the application
cannot use more than 2 (irl 1.8) on either platform. Not yet, anyway.

"Ivan" wrote in message ...
Did I read it here recently that regardless of the claimed max resolution of
high end flatbed scanners ie. Epson 4870, that when scanning negs the max
resolution is 2000dpi because of some issue with the glass?? Is this true?
If so then it stands to reason that MF is the logical choice of format
because it's the largest format that can be scanned on a dedicated film
scanner. A bigger format than MF will have to be scanned on a flatbed
anyways right? So unless you're shooting in a very large format (6x9
inches) you won't gain anything by scanning on a flatbed. Am I right? If
so then it's one more reason for me to invest in a few choice lenses for my
rb67.
Ivan


The reason many flatbeds come up short of their claimed resolution is
that the scanning lens isn't good enough. Manufacturers will often
install a higher density CCD without changing the lens.

Brian
www.caldwellphotographic.com

brian wrote:

"Ivan" wrote in message ...
Did I read it here recently that regardless of the claimed max resolution of
high end flatbed scanners ie. Epson 4870, that when scanning negs the max
resolution is 2000dpi because of some issue with the glass?? Is this true?
If so then it stands to reason that MF is the logical choice of format
because it's the largest format that can be scanned on a dedicated film
scanner. A bigger format than MF will have to be scanned on a flatbed
anyways right? So unless you're shooting in a very large format (6x9
inches) you won't gain anything by scanning on a flatbed. Am I right? If
so then it's one more reason for me to invest in a few choice lenses for my
rb67.
Ivan

The reason many flatbeds come up short of their claimed resolution is
that the scanning lens isn't good enough. Manufacturers will often
install a higher density CCD without changing the lens.

Brian
www.caldwellphotographic.com

Doesn't focusing distance count? Flatbeds are supposed to scan both from
the surface of the glass (opaque targets) and a little elevated
(transparencies). In high resolution scans they should have issues with
depth of focus.

-- Lassi