Scoping out the microscopy world

[mneium]

I'm currently looking around for a compound microscope capable of brightfield, darkfield and DIC.
As I understand it the Olympus BH2 and Nikon Labophot / Optiphot scopes are all popular, but the DIC and darkfield accessories seem extraordinarily rare and expensive these days (as the microscopes are from the 80s.)

My questions:

1) Would it be cheaper for me to go with one of these old microscopes and try to find the relevant DIC/darkfield accessories, or to go with a new scope where such accessories are readily available?
2) There has been forty years of optical advancements since the time when 160mm Olympus and Nikon's flagship plan-apochromatic objectives were created. From a standpoint of image quality, will I get better bang for my buck with a modern microscope than these old ones? I am aware that modern objectives are much more expensive, but are modern budget objectives better than old plan-apo objectives?
3) Is anyone aware of good places for buying used microscopes, besides ebay? I am interested in acquiring microscopes with plan-apo objectives from people who do not know how much they are worth
Oh, and:
4) Just to clarify, Nikon 160mm objectives are compatible with Olympus scopes (and vice versa,) right?
5) I read that "M" designation in an objective means "metallurgical" and is mainly used to survey the exterior of opaque objects. What do "S" and "D" (Olympus) stand for (is it just a product line with no meaning beyond the letter?) and what is CFM / CFI (Nikon)?
6) What is a DIC objective? I have seen some of these from Nikon. Is it actually required for DIC or merely somehow beneficial?

Thanks.

[PeteM]

Most any transmitted light DIC system will range from expensive to very expensive, used or new. One would be lucky to find a good used DIC system, complete, for under $3000. Exceptions might be PZO (older objective designs) and maybe Zeiss (older designs, some risk of delamination). A set Nikon prisms (in a universal condenser and above the objectives) alone might be found for $1500 for someone patient and lucky. You'd need a $1000 or so scope on top of that and maybe $1000 more for compatible objectives.

Olympus seem even harder than Nikon to find and more expensive. Reichert and AO are surprisingly good, but rare.

Reflected DIC systems, formerly used in the semiconductor inspection etc., are relatively common and affordable. That's where the MPlans fit in - most commonly for opaque objectives and the light source shining through the objective to the specimen and then back up into the head. I've been toying with the idea of preparing very thin biological specimens on a reflective background and no cover slip to try using these reflected systems, but haven't actually done anything with that notion. It's also possible to light smears from below (no cover slip) and use metallurgical objectives, but you won't get DIC.

I'm not aware of any new Chinese supplier providing a transmitted scope for under several thousand. Perhaps someone else can point us to one? Most don't even provide a DIC option.

Personally, I don't see much of a quality advance from top quality objectives made in, say, the 70's and those available now. Main advance since the 50's and 60's has been wider fields of view and better lens coatings (better contrast). A 20mm field of view is plenty for most of us (OK, 22mm+ even better) -- just fine for photography -- and the best quality objectives from the Olympus BH2 and Nikon Optiphot era hold up wonderfully in terms of resolution and contrast.

What these older finite systems lack is the ability to easily stack multiple imaging systems (phase, fluorescence, DIC, confocal, etc.) on a single stand, all at the same time, as might be done for a $100,000 scope in a research lab. Most of us don't need that.

Olympus DPlan objectives are good plan achromats with a field of view around 20mm.

Olympus SPlan objectives are better plan achromats (bordering on fluors) with up to a 26mm field of view. Seeing that 26mm field requires buying a special and $$$ microscope. It's worth it for some pathologists who have to scan hundreds of slides a day and want to see the "big picture" as quickly as possible before focusing their attention. SPlans are what Olympus recommends for DIC. I've tried Olympus objectives with Nikon DIC prisms and found SPlans and SPlanApos pretty good, and DPlan not so good.

Nikon, for its finite DIC system, wants "CFN" objectives labelled "DIC." The DIC labelling is somewhat like a polarization (P) rating - the glass in the objective is strain free and won't show defects when polarized light is used. Transmitted DIC uses two polarizers and two prisms to shear and re-combine the image.

Given the cost, the average hobbyist might want to wait a while before jumping into DIC. Lots can be done with regular brightfield, darkfield, oblique, polarization, and phase contrast. That said, the users of DIC systems here tend to be delighted and unlikely to go back to something like phase contrast.

[mneium]

(...)

Thanks for the reply.
Is the darkfield oil condenser ("DCW") still the best option for BH2 darkfield?
And while we're on the subject of condensers, is there any point to the "AAC" condenser?

[Rossf]

Hello mneium-I’ve got an AA condenser-my understanding is that they are far more corrected for chromatic and spherical aberration working in conjunction with the objectives to give the most corrected image possible, particularly for photography-the other advantage is it’s also an oblique condenser-you pull this metal side tab and it de-centers the condenser iris which gives a “light” DIC look-making outlines of amoeba ect more pronounced and an almost 3-D look-definitely a useful tool to have in ones microscope box of tricks. Search this forum for oblique lighting photos and I guarantee you will be quite surprised just how good oblique can be-there’s a member here-can’t think of his name atm but he goes by CanadianNaturePhotographer (I think!) and his use of oblique is amazing and beautiful.
Here are photos of my condenser (upside down) centre red and decentered-the glass elements are also got corrective coatings-you can see that bluish color side on just like the front of the objectives. Mine will be pried out of my cold dead hands....
Good luck ross

[Rossf]

Oh better clarify my Olympus is a BH-1- I know the BH-2 has an AA condenser but I’m not 100% sure if you can de-center it cos of the different condenser mount on the BH-2. I’m sure someone will clarify for you.
Ross

[PeteM]

(...)

. . . Is the darkfield oil condenser ("DCW") still the best option for BH2 darkfield?
And while we're on the subject of condensers, is there any point to the "AAC" condenser?

You can use simple darkfield stops inserted below the condenser up to 20x, maybe 40x. 40x and above objectives you'll want the matching darkfield condenser.

The U-AAC is a highly color corrected condenser; sort of like the difference between a 100x 1.25 na plan achro versus a 100x 1.4na plan apo objective but on the condenser side (typical Abbe 1.25na vs. Achromat/Aplanat 1.40na condenser).

Unless you're trying for the absolute best resolution, you'd probably want to spend the money on something else.

[mneium]

Appreciate the info. I'll keep an eye out for both of those condensers.

[Antartica]

So following up on this, is the AAC condenser interchangeable between the bhs/bh2 and BX?

I see this:
https://www.ebay.com/itm/Olympus-Micros ... 7675.l2557

which says it fits the BHS BH2 BX BH. That implies that any BX will also fit the BHS/BH2.

Which means this
https://www.ebay.com/itm/OLYMPUS-U-AAC- ... 7675.l2557

which is the AAC for the BX. But it looks like it fit the BH2/BHS. So can either one be used on the BHS/BH2?

[Antartica]

Just bumping my post above. Can anyone clarify whether the links I provided are true and are interchangeable between BX and BH2/BHS?

[mneium]

Just bumping my post above. Can anyone clarify whether the links I provided are true and are interchangeable between BX and BH2/BHS?

I searched around and found similar discussions without an answer. They are apparently mechanically compatible but no one knows if they're optically compatible.