New Epson Film scanner?

On Fri, 24 Feb 2006 07:10:08 -0600, "Two" wrote:


Hey, think up here. The process is called SCANNING. A tiny lens (or row of
lenses) is passed across a transparent medium. The lens is a given distance
from the film regardless of the size of the film. It doesn't matter how big
the film is - the lens is concerned with only the immediate area at any
moment.


If you're complaining that the new Epsons
aren't drum scanners, why don't you ****ing
say so, and design us a drum scanner for $750.

In any CCD scanner, the lens needs to image
the width of the subject (transparent or
reflective) onto the length of the CCD array.

Or you can play the Scitex game, where
multiple swaths of the original are stitched
together in software. This is how Scitex
maintains high resolution across large
media widths.


rafe b
www.terrapinphoto.com

On Fri, 24 Feb 2006 07:11:07 -0600, "Two" wrote:


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

Off your meds again, John? I suggest that you try thinking and logic for a
change instead of letting your stupidity run rampant.

Littleboy, if you take your scanner apart, are you going to find a big lens
that takes in the whole frame at once? I think not.


You will find a lens whose image circle has
a diameter that's large enough to cover the
length of the CCD array.

Furthermore, its focal length is chosen so
that a specific width of the subject media
is projected onto the CCD array.

Why are you incapable of accepting that the
imaging array has finite physical length?

Or are you saying, in the most roundabout
way imaginable, that the Epson still isn't
a drum scanner?


rafe b
www.terrapinphoto.com

"Two" wrote in message
...

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

Off your meds again, John? I suggest that you try thinking and logic for
a change instead of letting your stupidity run rampant.

Littleboy, if you take your scanner apart, are you going to find a big
lens that takes in the whole frame at once? I think not.

I'm going to find a big lens that takes in 56mm x something very small and
projects that onto something that's some arbitrary size x something also
very small. When this particular scanner scans 35mm, it only uses a 24/56th
of that arbitrary sized something. Sone other scanners use the whole of that
arbitrary sized something for both 35mm and 120. This is a sensible thing to
do, since it takes maximum advantage of that arbitrary sized something
whatever film size you are scanning.

David J. Littleboy
Tokyo, Japan

"rafe b" rafebATspeakeasy.net wrote in message
...

You seem incapable of recognizing
the role of the sensor. Until you
do so, nothing else matters.

The bottom line is this - does the larger lens for MF (or LF) give less
information than the smaller lens - per square millimeter, for example?

"Two" wrote in message
...
"rafe b" rafebATspeakeasy.net wrote in message
news
Have you lost your mind? There is no correspondence whatsoever.

This new Epson is still a CCD scanner. It's not
a drum scanner, and it's not a Scitex.

Does it not "scan" the negative/transparency by moving a lens across it?


Yeah, you got that part right, so I'm not sure where
you fell off the logical deep end.

Nearly all CCD scanners fall into one of two categories:

1. Lens fixed relative to CCD. The lens/CCD assembly
moves along a *single linear axis* relative to the film. Most
flatbed and flatbed/film scanners work this way.

2. Lens fixed relative to CCD. The film is moved along
a *single linear axis* relative to the lens/CCD assembly.
Most dedicated film scanners work this way.

Since there is only a *single linear axis* involved, the lens
must image the full width of the original onto the CCD.

Scitex high-end flatbed/film scanners add a 2nd
mechanical axis, and scan the image as N vertical
strips. Ie., Scitex uses *multiple linear axes*.

For the life of me, I can't understand how you can
be so confused about any of this.


rafe b
www.terrapinphoto.com

"reboot" wrote in message
...

"rafe b" rafebATspeakeasy.net wrote in message
...

You seem incapable of recognizing
the role of the sensor. Until you
do so, nothing else matters.

The bottom line is this - does the larger lens for MF (or LF) give less
information than the smaller lens - per square millimeter, for example?



Square millimeters aren't relevant here. Samples
per inch are. It's not an issue of lens quality.

Epson's just come up with a cheap way of giving
us more resolution -- as long as the width of our
original is 6.375" or less. With luck, you just might
get to scan your 6x12" trannies at the higher res.
The spec'd scan length is 11.7".

[CCD has 4800*8.5=40800 sensels. At 6400
spi, that's a width of 6.375".]

If I read the MacWorld article correctly, 35mm, MF
and 4x5 will scan at 6400 spi optical, and anything
larger will scan at 4800.

Do you have a better way? Let's hear it, then.


rafe b
www.terrapinphoto.com

"reboot" wrote in message
...

"rafe b" rafebATspeakeasy.net wrote in message
...

You seem incapable of recognizing
the role of the sensor. Until you
do so, nothing else matters.

The bottom line is this - does the larger lens for MF (or LF) give
less information than the smaller lens - per square millimeter, for
example?

It doesn't *need* to be physically larger, just a different
magnification/focal length, but the larger the lens, the harder to
correct residual aberrations.

Bart

"Bart van der Wolf" wrote in message
...

It doesn't *need* to be physically larger, just a different
magnification/focal length, but the larger the lens, the harder to correct
residual aberrations.


This being (still) a consumer/prosumer flatbed/film scanner,
both lenses will be tiny. I'm guessing both will be in the
neighborhood of 25 mm, f/8 or so.

I'm looking at the imaging lens from a Konica/Minolta MFP.
The front element is ~ 5 mm diameter. The rear exit pupil
is about 3 mm dia. Distance from rear element to CCD
surface is about 20 mm.

One of the main problems with flatbed/film scanners is the
heavily folded optical path. The subject image is bounced
several times before arriving at the imaging lens. On the
KM assembly I'm looking at, there are four mirrors and
five bounces.

On the LS-8000/9000 there is exactly one mirror -- and a
much larger imaging lens, approx. 75mm f/3.5 or so.


rafe b
www.terrapinphoto.com