J
jamie boyd
Hi:
Has anybody had any experience with this?
Rather an esoteric question, perhaps. For those who don't know, these
are thin (50-100 microns) slices of tissue embedded in a clear viscous
medium and sandwiched between thin plates of glass. Surface area of a
slide is 1 -2 inches by 3 inches and, like 35 mm slides, they are meant
to be viewed with transillumination. For high power stuff, we have
cameras (now digital ones mostly) mounted on microscopes. But getting a
good low power image of large portion of section can be more difficult.
A few people have published pictures made by putting the slides on a
flat-bed scanner. I have tried this, but I have a lousy scanner, and
have not been satisfied with spatial resolution nor dynamic range
compared to film.
Spatial resolution should be solved by getting a better scanner with
higher optical DPI. For what I want, about 10 micron resolution will be
more than sufficient, and if I've done the math right (1/(.010 mm * 25
mm/inch) = 2500 DPI), that's within the range of current machines, even
moderately priced ones.
Dynamic range is the more problematic, I think. I know there are
inexpensive 36 bit scanners available now. Are they substantially better
than 24 bit scanners? In some cases, colour is not important, and I
would really like 16 bit greyscale. Do any scanners do this? Also, just
having the resolution is not enough, the quality of the the A/D
conversion is important. If the extra 12 bit resolution is just noise,
it's not doing any good.
Suggestions re. what scanners to buy, or hints on getting good images
much appreciated.
jamie
--
Jamie Boyd
Dept. of Biological Sciences
Simon Fraser University
phone: 604 291 4442
http://www.sfu.ca/~jboyd/
Has anybody had any experience with this?
Rather an esoteric question, perhaps. For those who don't know, these
are thin (50-100 microns) slices of tissue embedded in a clear viscous
medium and sandwiched between thin plates of glass. Surface area of a
slide is 1 -2 inches by 3 inches and, like 35 mm slides, they are meant
to be viewed with transillumination. For high power stuff, we have
cameras (now digital ones mostly) mounted on microscopes. But getting a
good low power image of large portion of section can be more difficult.
A few people have published pictures made by putting the slides on a
flat-bed scanner. I have tried this, but I have a lousy scanner, and
have not been satisfied with spatial resolution nor dynamic range
compared to film.
Spatial resolution should be solved by getting a better scanner with
higher optical DPI. For what I want, about 10 micron resolution will be
more than sufficient, and if I've done the math right (1/(.010 mm * 25
mm/inch) = 2500 DPI), that's within the range of current machines, even
moderately priced ones.
Dynamic range is the more problematic, I think. I know there are
inexpensive 36 bit scanners available now. Are they substantially better
than 24 bit scanners? In some cases, colour is not important, and I
would really like 16 bit greyscale. Do any scanners do this? Also, just
having the resolution is not enough, the quality of the the A/D
conversion is important. If the extra 12 bit resolution is just noise,
it's not doing any good.
Suggestions re. what scanners to buy, or hints on getting good images
much appreciated.
jamie
--
Jamie Boyd
Dept. of Biological Sciences
Simon Fraser University
phone: 604 291 4442
http://www.sfu.ca/~jboyd/