Webmaster’s blog 2017
Alan Wood’s microscopical diary
On 11th February, Chris Thomas and Dennis Fullwood ran a workshop on making dry mounts of hair, fur and feathers attended by some very enthusiastic members. As usual, I was busy taking photographs and making notes and didn’t get a chance to make any slides, but I have since tried photographing hair under brightfield illumination and crossed polarisers, as recommended by Chris.
Human brown hair (brightfield)
Olympus SPlan 40× objective, NFK 2.5× photo eyepiece, 34 images at 1 µm intervals combined in Zerene Stacker
For the photo with crossed polarisers, I rotated the polariser for maximum extinction, and then rotated the stage to obtain the most attractive colours. The normal BH2-SVR stage on my Olympus BH-2 rotates 270°, which is very useful for composing photographs as well as for rotating specimens under crossed polarisers, even though it is not as precise as a proper polarising stage.
Human brown hair (crossed polarisers)
Olympus SPlan 40× objective, NFK 2.5× photo eyepiece, 28 images at 1 µm intervals combined in Zerene Stacker
I used to use a photographic polarising filter as the polariser (on top of the light outlet on the base), and a cheap disc of polarising film from eBay as the analyser (in the recess where the head’s dovetail fits). I eventually found the proper Olympus A-POL polariser and B-AN analyser at reasonable prices, and they give better extinction and no colour bias.
Olympus A-POL polariser (left) and B-AN analyser
Back in 1980 when Olympus replaced the BH compound microscope with the BH-2, they kept the mounts for the heads and nosepieces but changed the mounts for the stages and condensers. While trying out the vertical illuminator from my newly-acquired BHMJ on my BH-2, I discovered that Olympus also kept the 30 mm fitting for lamp houses on their metallurgical microscopes.
So either of these lamp houses:
- BH-LHM lamp house (6-volt 15-watt)
- BH2-MLSH lamp house (12-volt 50-watt)
can be used with any of these illuminators
- BH-MA Brightfield Reflected Light Illuminator
- BH-RLA Brightfield/Darkfield Reflected Light Illuminator
- BH2-MA Brightfield Vertical Illuminator
- BH2-RLA Brightfield/Darkfield Vertical Illuminator.
Olympus BH2-MLSH (top) and BH-LHM lamp houses
Olympus BH2-MA Brightfield Vertical Illuminator (top) and BH-RLA Brightfield/Darkfield Reflected Light Illuminator
The lamp houses need different transformers, the TE-II, TF or TGHM for the BH versions and the TGH for the BH-2 versions. The metallurgical objectives must be used with the matching illuminators; BH objectives with BH-MA or BH-RLA illuminators and BH-2 objectives with BH2-MA or BH2-RLA illuminators.
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About this blog
I am Alan Wood, webmaster for the Quekett website, and author of several web pages on Olympus microscopes. I spend too much time writing about microscopes and buying more equipment. I hope this blog will help me to focus on using my microscopes so that I have something to write about!