olympus phase contrast and olympus drawing tube

Everything relating to microscopy hardware: Objectives, eyepieces, lamps and more.
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solos42
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Joined: Tue Jul 05, 2022 7:44 pm

olympus phase contrast and olympus drawing tube

#1 Post by solos42 » Tue Jul 05, 2022 8:20 pm

Dear friends
I am searching marine organisms. I have got Olympus CH30 light microscope. I have got also Olympus BH-DA drawing tube. I attach this drawing tube to Olympus microscope. I publish articles in journals. I finished my PhD on marine organisms. I am not an academician at any university, so my opportunities are limited. I need to further my scientific work.
But I need phase contrast microscope such as Olympus CH2 or Olympus BH2. Because this drawing tube only works and compatible in these microscopes.
I search these microscopes, but they are expensive for my budget. Do you know of another microscope brand this drawing tube can fit or compatible? Does anyone have an alternative suggestion or opinion?
I attached my microscope and drawing tube.
Best regards
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PeteM
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Re: olympus phase contrast and olympus drawing tube

#2 Post by PeteM » Tue Jul 05, 2022 8:49 pm

One option would be to buy a complete phase contrast kit (objectives and phase condenser) of the type that clamps under the stage, such as the Olympus CH series. You'd need to check diameters of the condenser and make sure that whatever you got was the same size or slightly smaller (add a round shim or metallic tape) as the Olympus. I've seen these kits go for less than $150 on Ebay. The optics of these generic sets are quite as good as something like Olympus D Plan phase objectives, but not too far behind. You'd also want to be sure you had compatible eyepieces.

Another option would be to buy a complete finite phase contrast scope with similar head dovetail sizes and adapt your drawing tube to that. Some AmScope and Zeiss Jena models, for example, have a slightly smaller dovetail. Some Boreal and Hund-Wetzlar models have the same 42mm size as the Olympus. The top part of the dovetail of your old BH era drawing tube has set screws that can be cranked in a bit to fit. The bottom dovetail could be turned down a bit to fit, if you have access to a lathe.

solos42
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Joined: Tue Jul 05, 2022 7:44 pm

Re: olympus phase contrast and olympus drawing tube

#3 Post by solos42 » Tue Jul 05, 2022 9:20 pm

Dear Pete
Thank you very much for these valuable information. I will search first and second options. If I find a solution, I will inform you.

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woyjwjl
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Re: olympus phase contrast and olympus drawing tube

#4 Post by woyjwjl » Wed Jul 06, 2022 1:33 am

I am very curious about the role of the "drawing tube", simply projecting the image onto paper? And then trace the image by hand?

Why not take a photograph? Is it just a matter of cost?

As for the phase, the biggest cost is in the objective lens, I have seen 3D printed phase rings (placed near the iris of the condenser).

Finally, can you show the marine microbes drawn by the "mapping tube"? I'm very interested.

BramHuntingNematodes
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Re: olympus phase contrast and olympus drawing tube

#5 Post by BramHuntingNematodes » Wed Jul 06, 2022 1:47 am

Drawing has certain advantages, accentuating specific features is one I think. Every once in awhile, one can find a camera lucida to attach to the drawtube or eyepiece. I have an old Spencer so model that is incredibly beautiful, and it works well also. It could be an alternative if you find a cheap phase scope incompatible with the he Olympus tube. Having a bright field and phase setup at the same time might be useful.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

PeteM
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Re: olympus phase contrast and olympus drawing tube

#6 Post by PeteM » Wed Jul 06, 2022 5:37 am

A drawing tube doesn't so much project an image onto paper as project an image of a pen or pencil onto the specimen as viewed through the eyepieces. A subtle difference perhaps, but not really like viewing a faint image projected onto a piece of paper and tracing around it.

With a drawing tube, you're gazing into the eyepieces while creating a drawing - and both the image and the pencil/pen point are clearly illuminated. It feels fairly natural and comfortable.

As Bram says, sometimes a drawing can better illustrate things than a photo - whether done freehand, copied over a projection, or done with a drawing tube. Probably more true in the film capture past, when we had less ability to digitally alter and enhance images, but still a useful capability for those with the patience, skill, and need to make clear illustrations of microscopic subjects.

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