Is it ok to use metalloscopy objective in biology microscope?

[osterport]

I need a good 10x APO objective in my Motic biology microscope, but sometimes I also use it to take pictures of small things like mosquito.

There are some quite cheap metalloscopy APO objectives on the market, has anyone used it in biology cases like diatom? Is the APO image quality compromised?

I noticed such objective does not support coverslip compensation



Thanks

[Alexander]

Metallurgical objectives work in transient light as fine as in reflected liegt.

The question is: fits the objective the system.

[osterport]

Metallurgical objectives work in transient light as fine as in reflected liegt.

The question is: fits the objective the system.

There are some M26 to RMS adapters on the market, it should not be a problem. My concern is more on the side of coverslip.

[apochronaut]

Such an objective would likely behave differently under transmitted light conditions, where the light is passing through the coverslip only once. However, it is planapo and any deviation from it's required operating environment can only tip it's performance off specification. The most obvious deviation would likely be spherical aberration, lowering contrast and the definition of detail some but the question is : how much? Maybe someone out there has tried ?
It is true though, that usually a .28 objective is so little affected by the coverslip that it becomes more or less invisible but with an apochromat where the performance parameters are at such a high level, small errors introduced into the design corrections would be more obvious : less margin of error to stay within spec.There must be a reason that it is marked with a 0, rather than a -
These are still not cheap and using one outside if it's comfort zone might not be much of an improvement over a really good transmitted light planachro. It also would prefer a 200mm reference length, require an R.M.S. thread adapter and is I believe comparable in parfocal length to Mitutoyo : 90mm so with an added adapter , quite long and cumbersome to use in a 45mm parfocal system.
I note that you are already using at least one Reichert infinity corrected objective in your system. There is available for some time now, a matching 45mm parfocal R.M.S., 10X .25 Reichert Austria planachro, if you are looking for an inexpensive quality 10X objective. It has nothing to do with me but I have bought Reichert objectives from the seller before and they are reliable. If you are interested, send me a p.m. and I can find it and send you a link.

[Alexander]

Metallurgical objectives work in transient light as fine as in reflected liegt.

The question is: fits the objective the system.

There are some M26 to RMS adapters on the market, it should not be a problem. My concern is more on the side of coverslip.

Fitting into a system is more than just the thread.
- parfocal length
- reference length
- tube lens corrections

[Phill Brown]

Optimised for epi illumination?
What 10x do you have?

[Scarodactyl]

This will not work. Optically it's fine, Motic's tube lenses are made to the Olympus standard and will play perfectly fine with mitutoyo spec objectives (though it would give 9x rather than 10x magnification), and at NA 0.28 you won't have coverslip issues. They also don't mind transmitted light. But aside from purpose built electrophysiology setups you won't find an off the shelf biological microscope that will physically fit a 95mm parfocal objective like this. Mechanically it's a nonstarter, and even if it could be made to fit the 50mm parfocality difference with your other objectives would be a nightmare.

[PeteM]

Assuming your Motic biology microscope has infinity corrections, you might look for a used Olympus 10x Plan Fluor or Plan Apo objective. Up to 10x, the M Plan (metallurgical and no cover slip corrections) should be fine - and perhaps a bit less expensive.

[osterport]

Thanks for all the reply and help. The motivation of this idea is to buy a cheap metalloscopy objective for multiple purpose.

However, the focal length is an issue, it's way too long ( 95mm ). Besides the one I tried to buy is tainted with fog, I gave it up.

Still I want to use such objective on a biology microscope ( keep two sets of scopes are too much for me ). I even designed a small 3D Stage that can be mounted at the condenser holder.