Webmaster’s blog 2017

Alan Wood’s microscopical diary

February 2017

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.

Brown human hairHuman 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.

Brown human hair (crossed polarisers)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 and B-AN analyserOlympus A-POL polariser (left) and B-AN analyser

January 2017

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-MA Brightfield Vertical Illuminator and BH-RLA Brightfield/Darkfield Reflected Light IlluminatorOlympus BH2-MLSH (top) and BH-LHM lamp houses

Olympus BH2-MLSH and BH-LHM lamp housesOlympus 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.

↑ Top of page

Commenting on this blog

If you would like to comment on anything in this blog, please contact the Webmaster.

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!