Re: photomicrography with Olympus E-500

"Way beyond"? - This is a common misunderstanding.

What is the active pixel size of this camera's image sensor? Since it uses a
Bayer filter, it should be SQRT(2) times the physical dimension of its
pixel. Is the active pixel size around 2.9um or less?

For example, Nikon's CFI60 Plan APO 4x lens offers an NA of 0.20. Using blue
light with a wavelength of 475nm, the smallest resolvable distance (diameter
of Airy disk) is just about 1.45um. Hence, the smallest resolvable distance
in the intermediate image plane is then 5.8um. The active pixel size should
then be around 2.9um to satisfy the Nyquist theorem. Since the image sensor
in question is using a standard Bayer filter, the resolution in blue (and
red) is less than for green. The factor is SQRT(2). Therefore, any image
sensor using a Bayer filter requires a physical pixel size of 2.05um to be
able to fully resolve the image of the microscope when using the objective
mentioned above.

The E-500 has an image sensor with 8.9 million photo detectors. The size of
this image sensor is 18mm by 13.5mm. Assuming square pixels, I calculated a
pixel size of 5.2um. No? - Hence the active pixel size for blue light is
around 7.4um, which I cannot call "way beyond".

Knowing the diameter of the FOV to be 25mm for the above objective, which is
significantly larger than the image sensor, the microscope offers more image
data than this camera's image sensor is able to capture in one exposure with
any relay lens. Of course, using a 2x or 4x relay lens will reduce the FOV
and hence will allow this camera to sample the image adequately but by
losing a significant amount of the FOV.

Gregor

<rander3127@xxxxxxxxx> wrote in message
news:1145423347.048877.261860@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
I haven't, I use an E-1 but with it's terrific image quality and 8
megapixels, it should be capable
of going way beyond the resolution of any microscope that I can think
of. The only issue might be higher noise than Canon or Nikon at higher
ISOs. But in most cases, you'll want to stick to lower ISOs to
preserve colour qualilty and dynamic
range. Also, auto WB (if it matters) is pretty accurate most of the
time, unless the lighting is
really "off sunshine."



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