Gossip meeting “Home-made or improvised equipment for microscopy”
Tuesday 10th July 2018
A good crowd of Quekett members turned out on a day that provided a bit of relief from the heat-wave and brought along some interesting items that stimulated lots of gossip.
Lisa and Nigel Ashby brought their Pentax digital SLR with an RMS adapter fitted to a body cap, a 2-way rotating nosepiece and a couple of microscope objectives, an interesting arrangement for macro photography.
Rotating nosepiece on SLR camera
Nigel is a descendent of William Watson, and he and Lisa are building up an interesting collection of Watson slides and equipment. In order to avoid frequent plugging and unplugging of low-voltage lamps for their stereomicroscope and the epi-illuminator of their Standard Metallurgical microscope, Lisa and Nigel have built a box with 3 sockets and 3 switches. It was too heavy to bring to the meeting, so they brought some photographs instead.
Switched power supply for Watson lamps [by Lisa Ashby]
Rear of power supply for Watson lamps [by Lisa Ashby]
Kit Brownlee used one of the Club’s Wild microscopes that has a substage filter holder to show how to produce dark-ground and oblique illumination using a 3×7 cm piece of card with a 45° arrow shape at one end. It needs to be carefully positioned on the filter holder, but produces interesting effects.
Kit Brownlee’s exhibit
Dennis Fullwood explained how he uses plastic picnic bowls as yellow pan traps for insects; just add some water and a drop of washing-up liquid. To extract specimens from the water, Dennis pours it through a fine mesh (100 µm polyester) held in an embroidery hoop, and then puts the hoop on the stage of a stereomicroscope. To see the traps and hoop in use, come to a Quekett excursion.
Dennis also showed the items in the following photograph: (1) a set of tongue depressors with silicon carbide wet & dry paper in 600 grit (coarse), 1200 grit (medium) and 2500 grit (fine) for cleaning and/or reshaping forceps and other dissecting equipment; (2) a medium-sized manipulator for lifting Collembola out of deteriorated mountants, consisting of silicone rubber tube (1 mm bore, 2 mm o.d.) cut at 30° on the end of a piece of stainless steel rod held in a pin holder; (3) some implements intended for removing ear wax (NOT a good idea) that make handy spatulas, probes or balsam rods; and (4) a laminated guide for lining up several sizes of coverslip on a slide.
Dennis Fullwood’s exhibit
Graham Matthews brought along 3 devices for us. The smallest was a specimen holder on a microscope slide, with a needle held horizontally through 2 supports. One end of the needle has a small plastic knob so that it can be rotated, pushed or pulled, and the sharp end holds the specimen over a black felt background (this can be slid out to use white paper or any other color). Inspiration for the design came from Brian Darnton, who uses something similar to hold forams for photography.
Some Leitz microscopes use a boat-shaped condenser that does not have a filter mount; Graham has made an attachable mount with centering screws for a dark-ground stop. Graham is keen on the square-based Baker microscopes that many of us remember from secondary school, and brought one that he has modified with variable LED lighting and a £12 Chinese mechanical stage.
Baker school microscope and Leitz condenser filter holder
Graham also brought a copy of A Beginners Guide to Freshwater Microscopic Life by David Seamer, whose books are very popular with members of the Amateur Microscopy group on Facebook. The books are only available direct from the author in Australia, Contact the Webmaster for details.
A Beginners Guide to Freshwater Microscopic Life by David Seamer
Jacky McPherson’s stereomicroscope is mounted on a boom stand and sometimes she wants a stage, so she has adapted a sheet of glass as a gliding stage.
On top of the glass plate, Jacky sometimes uses a small Petri dish with angel-eye LEDs, powered from a Maplin transformer. For manipulating specimens, Jacky makes fine needles by heating and drawing out capillary tube over a tealight.
Gliding stage and LED lights
Jacky also brought a cheap light-box intended for displaying 3 rows of letters; she covers part of it with pieces of black foam-board when she is viewing slides.
Jacky has been experimenting with extracting fossil Oamaru diatoms, a process that involves hot, strong acids with unpleasant fumes. She showed us a photograph of the vented enclosure that she uses in her garden.
Ventilated box for fossil diatom processing [by Jacky McPherson]
Maurice Moss brought along an eyepiece tube adapter that Tony Saunders-Davies made for him several years ago.
If you have been on one of the Quekett excursions, you have probably seen Maurice using his Nikon Coolpix 4500 attached to an NCP-995A photo relay lens that is designed to replace a standard 23.2 mm eyepiece. The adapter allows Maurice to use it with his stereomicroscope, which takes larger eyepieces.
Eyepiece tube adapter
Stephen Parker brought a small portable microscope that appeared to be home-made. It took a single RMS objective and a non-standard eyepiece, and fine focus was by tilting the stage.
Home-made portable microscope
Stephen also showed a home-made object finder slide, and an Abbe-type test slide that may have been made by Gilbert Hartley.
Object finder slide and test plate
Robert Ratford brought a book that is popular with beekeepers, Microscopy on a Shoestring by Owen Meyer. Robert had bought the book on eBay together with a few items made by the author, and he showed us a wooden illuminated base for a microscope.
Robert also brought something more modern, a telescopic selfie stick to which a telescopic back scratcher can be attached; he hopes to use this combination to collect samples from the bottom of ponds at Warnham Local Nature Reserve. Robert also brought a protective clear plastic top from a Cadbury Flake 99 ice-cream; the tops are useful for allowing suspended material in water to settle.
Selfie stick, back scratcher and ice-cream cover
Paul Smith brought a turbo-charged pooter that he devised for collecting ants from a dusty ceiling; it uses a vacuum cleaner for suction and has a hole that can be partially covered with your thumb to control the section!
Paul also showed a way to hold a cover slip tightly on a newly-made slide to minimise the quantity of mountant. A flexible steel filling blade from Poundland goes under the slide, and small strong magnets with handles go on top of the coverslip. Paul had also managed to make cotton buds stand upright with magnets.
Paul Smith’s exhibit
Paul also brought 2 small items that you can see in the photograph above. One was a makeshift stage micrometer, a piece of squared graph paper glued to a microscope slide. The other was a cylinder of green fluorescent perspex that can be used to demonstrate the light path above a substage condenser. Paul bought a 100 mm rod from Wholesale POS and cut, polished and lapped it to the size he wanted; Wholesale POS sell it as 19 mm and 25.4 mm diameter rods and will cut to any length for you.
Alan Wood repeated his demonstration from the 2017 Annual Exhibition, showing how to use an LED ring-light to produce either shadowless or dark-ground illumination for a stereomicroscope or macro photography.
Alan Wood’s exhibit
If you place an upward-pointing ring-light on the stage of the microscope with a black disc (card, paper or foam-board) inside the ring, you can get dark-ground illumination. Use a kitchen bowl with its base removed to hold a square of black foam-board with a circle cut out, and put a slide on top. Looking down through a stereomicroscope you should see the specimen brightly lit by the ring-light with a black background. The bowl is just a spacer and you need to find one of the right size for your system.
Dark-ground illuminator, showing (left) black disc, (centre) inverted bowl with base removed, and (right) the complete illuminator
Larva of a mosquito (Culex pipiens L.) on a slide by T. Gerrard & Co., using dark-ground illumination
By placing the ring-light on the stage of the microscope, pointing upwards into a white bowl (with its base removed), almost shadowless illumination can be produced, avoiding most reflections and revealing iridescent and other colours. The specimen needs to be placed in the centre of the LED ring, with a background of any suitable colour. Depending on magnification and working distance, you may need to prevent direct light from the ring-light reaching the microscope, so that the image is not spoiled by flare; this is easy to do with a cylinder of white paper just inside the ring of LEDs and/or a piece of white card with a circular hole on top of the bowl.
Shadowless illuminator, showing (top left) specimen pinned into a Plastazote disc, (top right) ring of white paper, (bottom left) inverted bowl with base removed, and (bottom right) the complete illuminator.
Bluebottle (Calliphora vomitoria), using shadowless illumination
Wristwatch mechanism, using shadowless illumination
Click the arrow to start the video (10 seconds), click the icon to the left of “vimeo” for a larger version
Yellow and grey lichens on twig, using shadowless illumination
Report and most photographs by Alan Wood