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Electron Microprobe Lab, University of Minnesota

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Ellery,
You are right of course. To attain film resolution one must have the
capability of acquiring 2048x2048 pixels or higher. Some digital
acquisition systems can of course do this. Of course this resolution is
only necessary if the ultimate resolution of the film media is required. In
my experience, we only acquire 4096 pixels or higher occasionally and never
for mere publication quality.

I think that it also depends on the digital scan generation. To allow for
high resolution acquisition at low to moderate mag, one should specify 16
bit D-A converters. Ignoring the last bit for digital "jitter" that still
gives one 8096 discrete beam positions. But to allow stage/beam drift
corrections a factor or 2 or 4 greater resolution than that is required.
Nobody makes anything better than 16 bit digital scan generation yet, but
someday.

But as you say, by allowing the software to mosaic multiple images,
arbitrary resolution can be obtained. Your idea of mounting a SLR digital
camera over the recording CRT is interesting.
john

At 09:36 AM 8/29/2005, you wrote:
>I was hoping to start a discussion on film vs digital acquisition.  Our
>8900 can, of course, digital record a BSE or SE image, but film remains
>superior until we collect a series of 1024 x 1024 images and stitch them
>together.  B&W film is being made by fewer and fewer manufacturers, and
>our lab stash has been expiring box by box for a while now.  I'm sure
>other labs are faced with similar things.  Requests for film photos are
>diminished to almost nothing in recent years, but I still hesitate to let
>this recording method disappear without having something as good as or
>better replace it.  I have been toying around with two ideas to do this:
>(1) mount a digital SLR camera above the film CRT and have it wirelessly
>send photos to a computer, or (2) purchase a commercially available
>digital acquisition system.  The second option is expensive, but the first
>option could get expensive too, would involve more work and
>experimentation, and would be more do-it-yourself.  The bonus is that more
>and more users have commented how nice it would be to have an electronic
>notebook of sorts, with easily grabbed digital images that they could
>label in Photoshop with analysis locations and so forth.  Has anyone added
>either of these options to their systems?  Is anyone still using their
>film regularly?  Or have you completely abandoned it, and if so, what have
>you done instead?
>
>Best,
>Ellery