Photo eyepieces for 1960/70s Zeiss

[IanW]

Hi - I know that this subject has been discussed previously but it has not really concluded to my satisfaction.

So - I have a Zeiss Standard 18 research microscope with trinocular head, semi-plan (160 tube length) objectives and 2 Kpl 10X eyepieces. I can use one to project an image onto the full frame sensor of my Nikon d810 using the photo tube and a 1960s Nikon F microscope adapter (which has its own internal lens too). However the image projected is too zoomed in, and not really pin sharp (even when using mirror lock up and front curtain shutter on camera).

Here is a shot using a 10X objective and 10X standard eyepiece.




I believe that photo eyepieces exist, but am unsure what would be the correct type to use with my set up.

Any thoughts/advice would be very welcom

[einman]

How are you focusing for the photo? Via the camera or via the Microscope's eyepiece?

The Nikon D810 is quite a nice camera.

[gekko]

Have you tried using your camera with its lens looking through one of the eyepieces ('afocal method')? This will ensure that the Kpl eyepiece will properly compensate the objective aberrations and you will not be introducing an unknown element (possibly introducing optical aberrations) by using a generic lens in the adapter. If you prefer to project the image directly onto the camera's sensor, then a Zeiss projection lens in place of the eyepiece will ensure that the proper corrections are applied. As far as I know (and that may not be very far), virtually all the old finite tube length microscope objectives (the high numerical aperture ones anyway) were designed to be used with matching compensating eyepieces since part of the optical aberrations were corrected in the objective and part in the eyepiece. The exception was the Nikon CF system where all of the corrections were implemented in the objective. Hence my preference for using the Kpl eyepiece in afocal mode or a Zeiss projection lens for projecting directly onto the camera's sensor. Another possibility is to use the Kpl eyepiece as a projection lens (by lifting it about 4 or 5 mm above its fully inserted position) and projecting the image directly onto the camera sensor, but the disadvantage would be that the field of view captured by the sensor would be much smaller than what you see visually unless you can obtain a very low power Kpl eyepiece. However, others may not agree with my opinions.

[75RR]

As far as achieving a sharp focus is concerned it is always best to ensure parfocality between the camera port and the binoculars. That way the camera will be focused when the binocular eyepieces are.
It is best to fine tune and test this with a fixed subject - like diatoms for example.

As to the field of view have a look at this article, I think it will help.

http://www.alanwood.net/photography/oly ... scope.html

[IanW]

Thanks for all the replies to my problems.

A few answers:

1. Einman - I have camera tethered to computer using digicam control software so focussing is done that way - and is actually easy to do.

2. I don't intend using camera with a lens attached pointed at eyepiece as the rigs I've looked at look far too cumbersome.

3. Otherwise experimenting with height of eyepiece might be interesting - will give that a go - thanks gekko.

4. 75RR - thanks for the link - full of information there - will take a while to digest.

Much appreciated!