November brought another Zoom gossip meeting, this time on “Micro fossils”. I wasn’t sure if I had any suitable slides to show, but I discovered a slide of radiolarian fossil earth from Barbados (made by Brian Darnton), got out my Olympus BH2-DCD dark-ground condenser and SPlanApo 10× objective and took this photo with my Canon EOS 5D Mark II and EOS Utility. Seventy images at 0.002 mm intervals combined in Zerene Stacker. Levels adjusted and sharpened in Photoshop Elements 11.
I just about got everything ready for the virtual Annual Exhibition of Microscopy. We decided to make the exhibits, the photomicrographs, the slides and the artwork available on separate days. I used a password to prevent members seeing the pages in advance, and then rushed to remove the passwords at the appointed dates and times. It all worked pretty well, and making everything visible in the public area of the website encouraged non-members to have a look.
When it became clear that it would not be possible to hold Quekex in the Natural History Museum this year, the committee decided to hold a virtual event spread over 6 days. Trying to hold everything on one day would have involved members staring at their computers for several hours, not good for their health or domestic harmony.
I normally take photographs and make notes at Quekex so that I can prepare a meeting report for the website, but with a virtual event I had to have everything prepared in advance. So I am back to working on the website instead of using a microscope. I had to convert all of the exhibits (supplied as Word, PDF and text files with lots of images) into web pages, prepare image galleries of all of the photomicrographs and slides submitted for Barnard Awards, and prepare pages to display the artwork and videomicrographs, all in time for the opening of the Exhibition.
For a while, it looked as though we were going to be short of photomicrographs submitted for Barnard Awards. I did not have time for any new shots, so I looked out some old ones and sent them off to Mike Gibson:
Another job that I have been meaning to do for ages is calibrating an eyepiece reticle for my SPlan and MSPlan objectives (the ones that I normally use for photomicrographs) using my stage micrometers. I have an Olympus Micro WHK 10x/20 L eyepiece with a built-in 10 mm reticle that is divided into 100 parts of 0.1 mm; the top section can be rotated to focus on the reticle. The reticle is cracked, but the markings are not affected.
I also have an assortment of old and recent 3″ × 1″ stage micrometers, including one for reflected light. I find the ones with engraved markings made by Graticules Optics (formerly Graticules Ltd) much easier to use than the modern Chinese ones with printed markings.
To calibrate, focus on the stage micrometer, adjust the lighting for Köhler illumination, and use the focusing helix on the eyepiece to get the reticle in focus. Use the mechanical stage to line up the zero points of the stage micrometer and the eyepiece reticle. Find a point where the 2 scales line up nicely; in the photo below, 60 reticle divisions equal 3 micrometer divisions, which we know are 0.1 mm apart. Then a bit of arithmetic:
(3 × 0.1 ) ÷ 60 = 0.005 mm
tells us that 1 eyepiece reticle division equals 0.005 mm for this objective.
I worked out the real sizes for 1, 10 and 100 reticle divisions for the objectives that I use most often:
For the August gossip on Ernie Ives’ slides, I showed photos and photomicrographs of two of his wood section slides and two of his insect slides. Ernie used a consistent layout for the 3 wood sections on his slides; the large section on the left is transverse, top right is radial and bottom right is tangential.
When I examined and photographed the insect slides for the gossip I was surprised that they were not up to Ernie’s usual high standard; one has lots of air bubbles, and the other has a broken specimen and very obvious supports for the coverslip that protect the specimen from being squashed..
Discussion at the gossip provided an answer: the slides appear to be Ernie’s early experiments with the Ralmount mountant.
I have finally had time to get the Olympus infinity-corrected metallurgical objectives and brightfield vertical illuminator that I acquired in October 2016 working with the TH transformer (modified to take 4 mm banana plugs) that I acquired in October 2018. The lamphouse uses a cable that only fits the TGH transformer, and I have failed to find one at a reasonable price. Despite having exploded parts diagrams for the lamphouse and the plug, I could not get access to the wires at either end of the cable, so I reluctantly cut it and then fitted an extension with heavy-duty Deltron bunch pin plugs.
One of the first things I tried was a human grey scalp hair, because I was trying to get a photo of the scales on the cuticle for the July “Hairs and fibres” gossip (our first Zoom meeting). The 20× MSPlan gave better results than my 20× Neo (from the BH era) but not as good as my 20× SPlan with transmitted light. I took some photographs with normal light and with crossed polarisers (the cortex of human hair is birefringent) and showed them during the gossip.
I don’t make permanent slides, so to hold the hairs straight I stretched them across an aluminium cell slide and fastened them with Mineral Tack.
Using polarisers gave me an idea for a presentation on getting started with polarised light microscopy for the next Zoom gossip, the joint meeting with the Bournemouth Natural Science Society. I showed how to use a photographic polarising filter as the polariser, a disk of polarising film as the analyser, and all sorts of plastic film as a retarder. I have been accumulating pieces of plastic film to test as retarders, and I devised an annular mount to make it easy to hold and rotate them; it was easy to make with a compass cutter.
In addition to the PowerPoint, I showed a live view through my microscope of adjusting the polariser for extinction, rotating the slide for the best image, and using a retarder to change the background and specimen colours.
With no meetings to go to, I have finally had time to clear the backlog of Olympus microscope instruction manuals, brochures, catalogues, exploded parts diagrams and repair manuals that I wanted to scan and convert to PDFs so that they can go on my website (www.alanwood.net/olympus/downloads.html). Some of them came from Brian Bracegirdle’s estate, some were donated by other people, and others came from Club meetings.
I have also had time to work out how to update the Quekett website to use HTTPS (Hypertext Transfer Protocol Secure) so that any passwords that members enter and any messages that people send are transmitted securely. You can check that the website is secure by looking for a closed padlock icon in the address bar of your web browser:
Pages on the Quekett website should also load faster, because web browsers use the faster HTTP/2 network protocol with websites that use HTTPS. It is not easy to prove that HTTP/2 is being used, but I found a Firefox extension (HTTP/2 Indicator) that puts a blue lightning bolt in the address bar:
On Saturday 2nd May I received an e-mail from the Rangers Office on Wimbledon Common asking me to phone them, and I was devastated to hear that Dennis Fullwood had died. The neighbour who sounded the alarm did not know how to contact his family, but she knew he was involved with the Rangers. They had my e-mail address because I send them photographs of Quekett activities on the common. Nobody in the Quekett or the Natural History Museum or the Kent Geologists’ Group knew of any family except an aunt in a care home somewhere. Lisa Ashby did a brilliant piece of detective work on ancestry.co.uk and traced members of the Fullwood family in Canada who knew how to contact a relative in Carshalton, so now we will be informed about funeral arrangements and Dennis’s estate can go to family members.
Kai and I miss being able to catch a bus and go for long walks on Box Hill, Headley Heath and Mickleham Downs, but the bus ride does not qualify as a necessary journey. For exercise we are combining shopping with walks to the neighbouring towns, a round trip of about 5 miles.
Finally finished Amendment 7 to ISO 1750, after spending several days fixing all of the problems that ISO’s Word template introduced. It includes well over 100 entries like this, all meticulously checked and re-checked:
Now I hope to have some time for microscopy. There is no news of when we will be able to have normal microscope club meetings, but we have held a couple of committee meetings using Zoom, and we are hoping to use Zoom for gossip meetings and lectures. We are also working on contingency plans for a virtual annual exhibition.
No microscope club meetings to go to, and no meeting reports to write, so I have finally have the time to work on an amendment to add more pesticide common names to ISO 1750 Pesticides and other agrochemicals – Common names. I have all of the data in an XML file as well as on my website, so I have been working on an XSL stylesheet to transform the data into HTML that I can then import into the Microsoft Word file that ISO want. I really want to give this up so that I have more time for microscopy, but it is hard work trying to get ISO to set up a database of pesticide names.
I missed the AGM and the Reading Convention because we were in Thailand for our annual visit to pay our respects at the graves of Kai’s parents in a huge Chinese cemetery that used to be a rice field. The lockdown in the UK and the cancellation of most flights in and out of Thailand started while we were there, but fortunately our Thai Airways flight was not cancelled, although it was completely full because BA had abandoned their passengers. We came back to a very different world, not much traffic on the roads, queues to get into supermarkets, and no microscope club meetings.
Doug Richardson bequeathed his collection of nearly 2500 slides to the Quekett so that some of them could be added to the loan sets that members can borrow. There are lots of slides of insects and their parts, and many other invertebrates, birds, fishes, reptiles, mammals, plants, fibres and crystals. Nearly all of the slides were made by Doug himself, but there are a few by other people, including Brian Darnton, Vaughan Dodge, Dave Skeet and E. Markham.
Almost all of the slides have been photographed and have had Quekett slide numbers added, and a workshop was held on how volunteers can help transcribed the information on the labels into an Excel spreadsheet. The photos and data will then be added to the database of the Club’s slide collection. The participants were allowed to select any slides they liked to take home and transcribe the data.
I haven’t acquired anything new for some time, so for the “My latest microscopical acquisition” I showed the 2 ways I have been testing to photograph slides through microscopes at Club meetings. The more promising seems to be afocal coupling, with a Leitz Periplan 10×/18 eyepiece (from Microscopium) connected via a step-down filter adapter (from eBay) to an Olympus Zuiko 50 mm standard lens from the OM system, with an OM-EOS adapter (from eBay). This arrangement is rigid and parfocal. The other way is eyepiece projection, with a simple microscope adapter (from eBay) from the days of 35 mm SLR cameras that clamps to an eyepiece tube and holds a normal eyepiece, connected to a camera with a T-mount.
If you would like to comment on anything in this blog, please send me a message.