Re: Need advice regarding Watson metallurgical microscope

Kevin Cunningham wrote:

Chris, Parfocality requires the that the eyepieces be made by the
manufacturer. There are way to many problems is you use some one
elses eyepieces. When examining an objective turret you have to use a
precentered objective and eyepiece or spend some time with a set
specimen and a set field diaphragm, the variance for a bad 'un is way
to small, a few microns between two positions.

Do you mean that all the lenses need to be made by the same manufacturer as the microscope body, or just that all the lenses need to be made by the same manufacturer? Even with Watson lenses together with a Watson body, it doesn't seem to work perfectly in these microscopes. The lack of parfocality is just sufficient that you need to turn the coarse focusing knob to correct it. I found one article online saying that you shouldn't need to turn the coarse focusing knob after switching lenses, but the article referred to a modern-looking Nikon microscope. I don't know if this is reasonable on microscopes made in the 1950s. Perhaps it is. Any idea?

Geez, yes, sometimes a cover glass corrected objective is used on non-
cover glassed specimens and if the NA is above 0.25 the results are
quite bad. You get tons of hazy and lots of fun with non-corrected
problems that would be corrected by using the right cover glass. Now
for obvious reasons metallurgists don't use cover glass and they do
use reflected light. If you need these two things then a metallograph
is for you. If your not looking at prepared metal specimens then you
just don't need a metallograph. Remember the prep these instruments
are designed to use looks like a hockey puck.

It sounds like I'll probably get an passable image with lower power lenses. I wondered at first if there was a fundamental difference between transmitted and reflected light lenses, such as an extra pathway to carry the illuminating light. But it seems not. Even if the results with higher powered lenses are poor, it looks like I should be able to track down a reflected lens to use for not too much money. They don't look outrageously expensive on eBay. And achromatic lenses should work with any eyepiece, shouldn't they?

I'm still not certain what would happen if I put a lens intended for a 200 mm tube length in a 160 mm tube microscope, though. Would it be bad, or would it be okay?

I'm tempted. I'll let you know which way I go.

Best wishes,

Chris

.

Relevant Pages

  • Re: Newbie question about macro with DSLR
    ... The beam splitter splits the optical path. ... Keep in mind that objective lenses are ... It replaces the ocular ... on a normal microscope when a camera is to be attached ...
    (rec.photo.digital)
  • Re: Newbie question about macro with DSLR
    ... macro photography, and I'm looking for advice regarding macro lenses, ... You need a microscope. ... lenses that allow a greater lense to object distance. ...
    (rec.photo.digital)
  • Re: description of camera design I would like to have
    ... I suggested the pentaprism design so that the same eyepiece optics in the ... as it can be readily adapted to use 4/3 lenses with a special adaptor tube. ... It even looks like a "mini SLR". ...
    (rec.photo.digital)
  • Re: What Kind of Eyepiece
    ... I need to view the object with an eyepiece, ... eyepiece lens or optics to look for. ... This is more akin to a door peephole viewer than to an eyepiece. ... I have paraxial solutions that solve the problem but the 2 or 3 lenses ...
    (sci.optics)
  • Re: description of camera design I would like to have
    ... An eyepiece pointed straight ... I suggested the pentaprism design so that the same eyepiece optics in the ... especially lenses, but also other attachments ranging from special eyepieces ...
    (rec.photo.digital)