Re: Canon 5D for photomicrography

In article <8usMe.3625$Hn3.2122@xxxxxxxxxxxxxxxxxxxxxxxxxx>, GTO <gregor_o@xxxxxxxxxxxxxxx> writes 
The number of pixels is not too relevant. More important is how much of the
actual FOV is projected correctly onto the image sensor. Remember, most 35mm
camera setups for microscopes are rather unsuitable for a DX format sensor
(cropping factor  = 1.5) since you lose a significant portion of the image
information due to a too small image sensor.

Of course, 13MPixels are more than enough for a 40x objective. But remember,
you can always reduce the image size using a "smart interpolation" in post
processing (such as PaintShop PRO 9). Any oversampling artifacts are then
nicely eliminated and you obtain a beautiful image of most of the available
FOV. If the sensor is smaller, then you need to replace the relay lens in
your setup, which is highly non trivial, impossible, or very expensive
should you require highest quality. Or you accept vignetting by projecting
the entire FOV directly onto the image sensor, which can be accomplished by
using the newer scopes that do not require the relay lens to fully correct
for CDM (e.g. my setup using a Nikon D70 on a Nikon E400 scope.)

I welcome the idea of a full format sensor for photomicrography. Many older
microscopes have beautifully working adapters/relay lenses for the 35mm
format. Too many pixels can be dealt with in post processing if really
necessary.

Gregor

PS: I do not think full format CCD/CMOS sensors are really necessary for
photography. I do not believe that there is anything magical with the 35mm
format. But for photomicrography, it is an advantage when trying to use
older relay lenses that are now affordable and sold on eBay.

Gregor, you might feel a little differently if you had a not very small fortune invested in EF lenses, as I have! Besides, I believe that for a given parameter of sensor noise to unit sensor pixel area, a given number of pixels in a 35mm sized sensor will be better than the same number in a 1.6 factor or smaller sensor. 

"justbeats" <steve_beats@xxxxxxxxxxx> wrote in message
news:1124176796.436716.297030@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

13 MPixels in a 35mm sensor - that's going to be 6um pixels or so?
Isn't that just going even further into oversampling territory?

   Cheers
   Beats




--
David Littlewood
.

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