[Histonet] RE: Digital Photomicroscopy

Tue Oct 28 11:08:02 CST 2003

Mikael writes:  << If I understand correctly, the resolution of modern
digital cameras is actually so high that at least with moderate to high
magnification the limiting factor is the resolution of the microscope
objective, not the camera. So you don't really get any extra information
using film.>>

That is true. It may seem backwards to some, but the higher the objective
magnification, the less camera resolution needed. That is because you are
imaging a very small field of view. Even a 1 or 2 megapixel camera can get
good images with a 100x oil objective. You would only need very high
megapixels if you were trying to get maximum resolution at very low
magnification - say 4x. 

Since that is the case, the limiting factor becomes the quality of the
optics. We saw that here when we demoed a high-end Nikon 40X oil lens and
compared it against our standard dry 40X. The difference was amazing. But
you'll spend $4000 for that lens, so you have to decide on the trade offs.

I would say for 20x objective and up a 3 to 5 megapixel camera is fine. And
if all you print is 2" to 4" images, then 3 megapixel is just fine. You only
need more pixels if you plan to make poster-size enlargements. 

In any case, get a camera designed to fit on a camera mount on the
microscope. A jury-rigged camera setup will never give you the same quality
- even if the camera and microscope are good quality.

Tim Morken
Lab Vision / NeoMarkers
www.labvision.com

-----Original Message-----
From: Mikael Niku [mailto:mikael.niku <@t> helsinki.fi] 
Sent: Monday, October 27, 2003 11:57 PM
To: grantgd <@t> comcast.net; histonet <@t> lists.utsouthwestern.edu
Subject: [Histonet] RE: Digital Photomicroscopy

Gordon,

we have a BH-2 and changed from film to digital a few ears ago. 

We first tried a few "normal" digital cameras the Nikon D1 digital SLR,
for example), but it seemed o be difficult to attach the camera to the
scope properly you probably need an expert adaptor company to do his, at
least with the old scopes).

With the cameras specifically designed for microscope work there were no
major problems, and we finally got a Colorview12 camera + image analysis
software by Soft Imaging System. With a resolution of 1280x1024 pixels
and less than perfect color reproduction, there are better cameras
available today. But even this IS enough to produce decent publication
images (the minimum resolution most  journals ask is 150-200 dpi, so you
can produce images at least 16 cm wide, which is of course much larger
than most images in scientific publications). I actually won a
honorable mention in the Nikon international photomicrography
competition last year using this camera, so it can't be that bad.

I never used film since getting the digital camera; the lot of slide
film I bought slightly before is still sitting in the freezer. It is
true that the resolution of even the best digital cameras is
theoretically less than that of film. But for most scientific
publishing, there is no practical difference (see above). If I
understand correctly, the resolution of modern digital cameras is
actually so high that at least with moderate to high magnification the
limiting factor is the resolution of the microscope objective, not the
camera. So you don't really get any extra information using film.

My view is that with digital equipment one can produce at least as good
quality images as with film, but digital is a LOT easier and quicker to
use. You must note, though, that to get really optimal results, you need
to spend some time learning digital color reproduction and image
processing. But this is no different with film.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+  Mikael Niku		 
+  University of Helsinki, Dept. Basic Veterinary Sciences
+  URL: www.helsinki.fi/~mniku/
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

- Mitäkö mieltä olen länsimaisesta sivistyksestä?
  Minusta se olisi erinomainen ajatus!
					 (Gandhi)

> -----Original Message-----
> From: histonet-admin <@t> lists.utsouthwestern.edu 
> [mailto:histonet-admin <@t> lists.utsouthwestern.edu] On Behalf Of 
> Gordon Grant
> Sent: 27. lokakuuta 2003 16:59
> To: histonet <@t> lists.utsouthwestern.edu
> Subject: [Histonet] RE: Digital Photomicroscopy
> 
> 
> Hello histonetters,
> I have an Olympus BH-2 microscope fitted with a real nice 
> PM10AD Olympus film camera. I have been real happy with the 
> set up as I take a lot of publication photos. My problem is 
> digital is now the way to go. I borrowed a Coolpix MDC lens 
> adapter with a coolpix and Olympus C-5050 camera. I not very 
> pleased with the results. Does anyone have a recommendation for me.
> 
> Best
> Gordon Grant 

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