B&l research stand

[Radazz]

(Edited to update photo links)
I wasn’t aware that B&L made a body that swiveled forward before the Dyna-scopes in the ‘60s
S/N YD7517 1956. Variable N.A. condenser and precision stage.
Enjoy

[75RR]

Nice, like the light source as well.

[MicroBob]

Beautiful microscope! I looks like a very nice oldtimer for regular use.
I can't really see where it swivels - in the binocular head?

Are these eyepieces original? The entrance lenses have a very big diameter.

Bob

[apochronaut]

That's a nice one. You are obviously a B & L enthusiast. It's a small club, for no apparent reason.

Is that a polarizing condenser? N.A. is ? You may find some inexpensive apochromats around for very little for that.... not that it's achromats are shabby but apochromats are always a treat on a special stand. The quantity of B & L apochromats for 160mm fixed tube microscopes around. is disproportionately high on the used market when compared to those available from Spencer but oddly, the number of B & L research stands around is smaller. Might be because the horseshoe base Dynoptic got pressed into service as a research stand after the war, while they developed the integrated illuminator Dynoptic and the Dynazoom.

MicroBob. Both Bausch & Lomb and Spencer offered W.F. oculars in their catalogues, sometime in the 1930's. Spencer even offered W.F. compens eyepieces, which I have never seen. The F.N. of the B&L W.F. oculars is impressive. I've never measured them but the 15 X must be around 22, maybe 24? They were not plan compensating. All of them had quite wide eyelenses.

[Radazz]

There is a small knob on the side of the tube, that lets the head rotate where it sits atop the tube.

Apo, the condenser let’s you match the numerical aperture to what’s printed on the objectives.
Makes a difference at high magnification, but my old eyes can barely see it.

Actually I just play with these vintage scopes. For serious work I use the Nikon or the Axioskop, but these tickle all of my senses and are just fun to use and muse about.

And you are right, Apo I gotta admit I’m really enamored of these early to mid 20th Century American pivot based stands.
I have a few Spencer’s as well, but you can get a model 13 and a model 33 and you have about 30 years covered with those.

[apochronaut]

Thanks. Interesting stage too. I have never seen one with such a big knob, and the condenser focuser, extended out into such a convenient location. Looks like they intended yo to use it. That must have an achromat condenser.

[MicroBob]

These large fields of view are impressive for most people today - how impressed must they have been in the 1930s!
From the year of manufacture this microscope would be a contemporary of a Zeiss Standard GFL. It's interesting to see how different designs can be used to fulfil the same requirements.