Just curious, has anyone tried using a really good photo scanner (lots of
dpi) on microfiche, then enlarging the results?

Franklin Newton wrote:
Just curious, has anyone tried using a really good photo scanner (lots of
dpi) on microfiche, then enlarging the results?


Do you have any idea what the equivalent DPI is on last-generation
microfiche? If you have lines of text with 100 chars, and a 5 x 7
matrix plus the space between chars, that is about 700 pixels minimum
across the page, and most are MUCH higher resolution than that, like
about 4000 pixels across a page. Now, that page is reduced to less
than 1/2", so that is an absolute minimum of 1400 DPI, and much more
likely to be 8000 DPI. You need really fine optics to image this
stuff properly.

Jon

On Thu, 11 May 2006 04:27:19 GMT, Franklin Newton wrote:
Just curious, has anyone tried using a really good photo scanner (lots of
dpi) on microfiche, then enlarging the results?

Yes. Not so good but readable:
http://www.duck-creek.net/photos/dav...roke/section3/
for example.

These were made at 3600 DPI on an Epson flatbed scanner with
transparency adapter built in, which I'm told has the better of the two
scanner elements (CCD?) but haven't verified. It's readable but not by
much.

Dave Hinz

"Dave Hinz" wrote in message
...
On Thu, 11 May 2006 04:27:19 GMT, Franklin Newton
wrote:
Just curious, has anyone tried using a really good photo scanner (lots
of
dpi) on microfiche, then enlarging the results?

Yes. Not so good but readable:
http://www.duck-creek.net/photos/dav...roke/section3/
for example.

These were made at 3600 DPI on an Epson flatbed scanner with
transparency adapter built in, which I'm told has the better of the two
scanner elements (CCD?) but haven't verified. It's readable but not by
much.

Dave Hinz

Thanks, Your results at 3600 dpi were not bad at all, so a high end scanner
should be able to do it at less than the cost of a reader/printer or
dedicated scanner

On Thu, 11 May 2006 23:42:06 GMT, Franklin Newton wrote:

"Dave Hinz" wrote in message
...
Yes. Not so good but readable:
http://www.duck-creek.net/photos/dav...roke/section3/
for example.
These were made at 3600 DPI on an Epson flatbed scanner

Thanks, Your results at 3600 dpi were not bad at all, so a high end scanner
should be able to do it at less than the cost of a reader/printer or
dedicated scanner

Probably 300 or 400 bucks would get you there, or you could get this
model used on eBay pretty cheaply. I like Epson's scanners and will buy
another some day.

What you need is back lighting - through frosted milk glass.

You can get some of that at a glass company. The scanner reflects off the surface
with the internal lamp - hope you have a way to turn it off. I do on my HP -
I plug in the Slide / film unit and it is a lamp. Turns off the internal reflection
lamp.

Martin

Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH & Endowment Member
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member


Franklin Newton wrote:
Just curious, has anyone tried using a really good photo scanner (lots of
dpi) on microfiche, then enlarging the results?



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On Fri, 12 May 2006 21:43:22 -0500, Martin H. Eastburn wrote:
What you need is back lighting - through frosted milk glass.

You can get some of that at a glass company. The scanner reflects off the surface
with the internal lamp - hope you have a way to turn it off. I do on my HP -
I plug in the Slide / film unit and it is a lamp. Turns off the internal reflection
lamp.

Well, you've just reinvented the transparency scanner. But lighting is
only part of it, resolution still isn't quite there. The example I
posted at 3600 DPI is mostly readable but hardly clear. Optical
resolution is the only thing that'll get you there.

3600 dpi in jpeg ? that trashes the data in compression -

or in TIFF that maintains high res.

That might be the issue - and are you sure it is 3600 in B&W or 3600 in color and you get B&W.
You might do a single page at a time. Put the res in the smaller box. You would have to have
done that or the file size would be a monster...


Martin

Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH & Endowment Member
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member


Dave Hinz wrote:
On Fri, 12 May 2006 21:43:22 -0500, Martin H. Eastburn wrote:

What you need is back lighting - through frosted milk glass.

You can get some of that at a glass company. The scanner reflects off the surface
with the internal lamp - hope you have a way to turn it off. I do on my HP -
I plug in the Slide / film unit and it is a lamp. Turns off the internal reflection
lamp.


Well, you've just reinvented the transparency scanner. But lighting is
only part of it, resolution still isn't quite there. The example I
posted at 3600 DPI is mostly readable but hardly clear. Optical
resolution is the only thing that'll get you there.


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On Sun, 14 May 2006 23:05:46 -0500, Martin H. Eastburn wrote:
3600 dpi in jpeg ? that trashes the data in compression -

True, but that assumes there's data there to begin with, and also
assumes I have a few gigabytes of webspace which I don't. The TIFF
scans don't look much better, same blur. You're seeing blur there, not
..jpg artifact.

You might do a single page at a time. Put the res in the smaller box. You would have to have
done that or the file size would be a monster...

Oh yes you definatly have to scan these one "page" at a time, not the
whole fiche. But the resolution just isn't there, even in the raw scans
at 3600 in TIFF.