Don Williams wrote:
I had hoped to hear from anyone in the group who has an *ist D attached to a compound microscope. I'd like to know if the shutter vibration is a serious drawback. I know the mirror can be fired in advance to help reduce this problem. But with a selection of other Pentax SLRs I found the shutter to be a real nuisance. I now use (for film) a dedicated Wild/Leica MPS 51 camera and MPS 48 electronic controller with a shutter that does not vibrate at all. But I'd like to move over to digital for routine work. I have all the attachments to fit Pentax bayonet bodies to my instruments.
Don,
I've used an *istD on a fairly sturdy microscope (binocular, so not ideal), with a standard Pentax adapter and using the 2 second mirror pre-fire to minimise vibrations. I haven't yet had a chance to exhaustively test out this arrangement, and I'm a long way from optimising everything but there's no reason why it shouldn't work well.
Here's one example: a closeup of some arthropod (can't remember which) leg - possibly taken with x40 objective, x10 eyepiece, 0.7s exposure.
Whole image:
http://www.ddixon.force9.co.uk/micro1.jpg
1:1 detail:
http://www.ddixon.force9.co.uk/micro2.jpg
As you can see, the image isn't particularly sharp but it's not bad, and I believe that it is the optics rather than vibration that's causing this lack of sharpness.
Looking at another 1/125 s exposure (which is probably about the speed at which vibration is likely to have greatest effect), I get similar results.
Of course, using a flash as the light source would help solve vibration problems, and I've had some success introducing an unmounted flash tube into the pre-condenser optics. Again, I need some time to get this optimised though!
I hope this helps,
David
