Objective/microscope mix and match

Hello all. I have a Leica DMi8 TIRF microscope with a TIRF lens, 100x/1.47. The camera pixel size is 6.5um. I’d like to use it for dSTORM, and needs a 60x TIRF lens to reach ~100nm/pixel. Unfortunately, Leica has discontinued their 63x TIRF lens. I recently got an Olympus 60x/1.49 TIRF lens (APON60XOTIRF). I’m wondering if it’s possible to use an adapter, M25 to RMS, in order to use Olympus 60x on the DMi8. Do you see any disadvantage of this mix and match strategy? Thank you.

I think that Leica uses a 200mm tube lens and Olympus uses 180mm. You didn’t mention if your calculation includes this, but if it doesn’t the pixel size might not be quite what you expect. However it should be close enough.

Another option might be putting a de-magnifier in front of the camera and using the Leica 100x.

In general, unless you are going for a really large FOV you shouldn’t have much trouble. I’ve used Olympus objectives on Nikon microscopes for SMLM without issues.

-Hazen

Olympus and Nikon are generally interchangeable, just beware the 11% magnification mismatch Hazen noted.

However Leica and Zeiss objective lenses are designed leaving some of the corrections to the tube lens, specifically lateral chromatic correction for both and possibly also curvature in the case of Leica. Thus Leica and Zeiss objectives should be used with the corresponding tube lens, and thus the spacing between objective and tube lens is specified to be within a certain range. In contrast, Nikon and Olympus correct the objective completely (harder to do optically) but the benefit is more flexibility.

Regarding magnification, EFL of tube lenses are 200mm for Leica and Nikon, 180mm for Olympus, and 164.5mm for Zeiss. Magnification is the ratio of tube lens focal length to objective focal length. These 4 major manufacturers also have different conventions for mounting threads and parfocal length.

A very handy reference: https://amsikking.github.io/microscope_objectives/index.html, and if you want more details https://doi.org/10.1515/aot-2019-0002.

Thank you @JonD for sharing the link. Can I say, other than the 10% magnification difference, Olympus objective can be used on Leica microscope. But the opposite is not true because the Leica objective relies on Leica tube lens to make more correction?

Thank you @Hazen_Babcock for sharing. Ideally I would need a 0.65x demagnifier for using 100x objective and 6.5um pixel size to reach 100nm. I can only find the following [Leica 0.7x c-mount]. (Leica Microscope Camera Adapter HC C-Mount 0.70x 11541543 – Microscope Marketplace). Would this work?

Yes that should work. The resolution of dSTORM is not particularly sensitive to pixel size.

Thank you very much.

Can I say, other than the 10% magnification difference, Olympus objective can be used on Leica microscope. But the opposite is not true because the Leica objective relies on Leica tube lens to make more correction?

Neither the Leica tube lens and Leica objective and perfectly corrected alone but conceptually the deviations are equal and opposite and so when used together they cancel out. So no, I do not expect an Olympus objective paired with a Leica objective to give a well-corrected image.

In some situations the imperfections may be tolerable, especially if you are doing single-color imaging or have some downstream way of correcting for lateral color (i.e. wavelength-specific magnification) which is the main aberration is split according to the literature. Generally speaking low-NA imaging is less sensitive to aberrations. And if your dSTORM PSFs are spread out a bit more can still localize them.

Because all you have to buy is a thread adapter it’s probably worth trying out. I’d be curious to know the experimental results since all I can speak to is the theory.

Thanks @JonD for clarifying. I will keep that in mind. Now I’m only interested in one-color. I will see how it goes with the M25-> RMS adapter, and compared it 100x with 0.7x C-mount.