East of England Meeting

Saturday 23rd October 2021

Dave Skeet organised his third joint meeting of the Eastern Counties Microscopy Study Group and the Iceni Microscopy Study Group, and despite worries about Covid-19 it was a great success with lots of interesting displays and lots of enthusiastic microscopists. The event was held in the Village Hall in Bradfield St George in Suffolk, with exhibits and a few sales in the morning, followed by lunch and then a talk in the afternoon. There was coffee, tea and biscuits ready for us when we arrived.

Bradfield St George Village HallBradfield St George Village Hall

Since the previous meeting in October 2019, we have lost Lewis Woolnough (who lived locally and started the meetings) and Barry Ellam.

Lewis Woolnough receiving his Eric Marson certificate from Joan BingleyLewis Woolnough receiving his Eric Marson certificate from Joan Bingley at the 2019 meeting

Peter Sunderland and Barry EllamPeter Sunderland and Barry Ellam (right) at the 2019 meeting

Exhibits and sales

Joan Bingley brought a black and brass Zeiss “jug handle” microscope that Barry Ellam helped her to get working properly at the Juniper Hall weekend in 2013. To demonstrate it, Joan used a slide of a gall on a weeping willow leaf made by Robin Wacker and sold on his behalf by Barry.

Joan Bingley’s exhibitJoan Bingley’s exhibit

Joan also showed the contents of nests of a robin and a blue tit, to promote the Quekett’s new project on the composition and invertebrate inhabitants of birds’ nests. She also showed a Tullgren funnel that Graham Matthews has designed for extracting arthropods from nests.

Birds’ nests projectBirds’ nests project

Gordon Brown brought 3 microscopes, a trinocular Leitz Dialux, a binocular Leitz DMLS, and a trinocular L300BHTG from GT Vision. On top of the Dialux is a camera adapter that Gordon obtained from Peter Evennett when he was clearing out unwanted items. Unusually, it includes an anti-vibration coupling. Gordon has, of course, modified the Dialux to use LED lighting. The GT Vision microscope was attached to the stacking system that Gordon has designed, and had an Eakins microscope camera on top. Gordon uses Affinity Photo to stack images for greater depth of field.

Gordon gave a talk on “DIY Stacking System for Microscopes” after lunch.

Gordon Brown’s exhibitGordon Brown’s exhibit

Gordon had removed the cover of his stacking device so that we could see the circuit boards and other components.

Gordon Brown’s stackerGordon Brown’s stacker

Dave Skeet and Gordon BrownDave Skeet and Gordon Brown (right)

Chris Kennedy and Gordon BrownChris Kennedy and Gordon Brown (right)

Ron Cushing displayed a selection of his excellent macro photographs and photomicrographs.

Ron Cushing’s photographsRon Cushing’s photographs

Steve Edler was selling items on behalf of Cath Varley (Bill Varley’s widow), to raise money for the Royal Microscopical Society’s Microscopes for Schools project. The biggest item was a trinocular Olympus BHSM metallurgical microscope (complete with polariser and analyser) that came with a nosepiece of ordinary objectives, a flip-top condenser, a phase contrast condenser and a set of BX objectives. Other items included a white Cambridge rocking microtome (with knife) and a stereomicroscope with an LED ring-light.

Trinocular Olympus BHSM metallurgical microscopeTrinocular Olympus BHSM metallurgical microscope

Alan Wood setting up the Olympus BHSMAlan Wood setting up the Olympus BHSM [by Robert Ratford]

Cambridge rocking microtomeCambridge rocking microtome

Steve Edler also brought an exhibit on cypselas, cremocarps and mericarps, the fruits and seeds of plants in the Asteraceae family (such as dandelions) and the Apiaceae family (such as cow parsley). They make excellent stereo subjects, particularly when viewed with top illumination on a black background, as we could see with Steve’s Meiji EMZ-1 stereomicroscope. Just by coincidence, Alan Wood was using the pappus of a dandelion seed to demonstrate stereo dark-ground illumination.

Steve Edler’s exhibitSteve Edler’s exhibit

Seed on black backgroundSeed on black background

Margaret Gillham showed the journal that she keeps with notes, drawings and photomicrographs of slides in PMS boxes.

Margaret Gillham’s PMS journalMargaret Gillham’s PMS journal

John Gregory brought along a selection of the slides that he has made, the tools that he uses, and some special slides for displaying forams (or other objects of similar size) on a black background in numbered squares. He provided a monocular Wild M11 with a gliding stage, a Kyowa SD-2PL stereomicroscope, a Meopta AZ-2 portable microscope, and a digital microscope with a built-in screen.

John Gregory’s exhibitJohn Gregory’s exhibit

John Gregory, Mo Vaughan and Chris ThomasJohn Gregory (left), Mo Vaughan and Chris Thomas

Andy Johnston has been having trouble getting his Nikon camera to work with the stacking device that Gordon Brown built for him, so he brought it to the meeting so that Gordon could help him. Andy uses it with his trinocular Zeiss Standard microscope.

Andy Johnston’s exhibitAndy Johnston’s exhibit

Andy JohnstonAndy Johnston

Chris Kennedy used his trinocular Leitz Dialux 22 microscope to demonstrate 10× and 20× long working distance reflecting objectives designed by Cooke, Troughton & Simms and sold by Vickers. The images were surprisingly good for reflecting objectives, which are notoriously difficult to use, but were lacking in contrast compared with normal objectives.

Vickers reflecting objectivesVickers reflecting objectives

Alan Wood with Chris Kennedy’s exhibitAlan Wood with Chris Kennedy’s exhibit [by Robert Ratford]

Bill Morris demonstrated silver crystals growing on a copper wire, viewed on a monitor via a Chinese inspection camera. He makes a loop of fine copper wire (from electrical cable) by wrapping it around a pencil, and places it in a solution of silver nitrate. A coin capsule is a suitable small container.

Cu + 2AgNO3 → 2Ag + Cu(NO3)2

Bill Morris’s exhibitBill Morris’s exhibit

The silver nitrate needs to be kept in the dark and dissolved in distilled water (not tap water). You need a very dilute solution, around 0.1%, so that the reaction does not proceed too quickly.

Tim Newton brought along a Greenhough-style stereomicroscope by Koristka that had been one of Barry Ellam’s favourites. Tim bought it from Barry’s daughters, Alison and Kate, at the 2019 Annual Exhibition in Northampton and subsequently visited Barry in his nursing home to collect some extra objectives. To show how well it performs, Tim brought some of his collection of beetles, illuminated by an Ikea Jansjö LED lamp.

Tim Newton’s exhibitTim Newton’s exhibit

Stephen Parker showed a Steindorff “Microbe Hunter” microscope that used to belong to Barry Ellam, and that Dave Skeet sold on Barry’s behalf at the 2019 Reading Convention. It is the basic model (mirror and Abbe condenser) and was not complete, but Stephen has replaced some missing screws and is looking for Steindorff objectives. So that we could try it out, Stephen provided some Biosil slides by John Wells that had belonged to Barry and were sold by his daughters, Alison and Kate, at the 2019 Annual Exhibition in Northampton.

Stephen Parker’s exhibitStephen Parker’s exhibit

Jane Corcoran admiring Stephen Parker’s exhibitJane Corcoran admiring Stephen Parker’s exhibit

Robert Ratford showed the 1 mm version of the ioLight portable microscope, with images displayed on his iPad. The microscope’s field of view is 1 mm wide, and the iPad screen is 160 m wide, so the magnification is 160×.

Robert Ratford’s ioLight portable microscopeioLight portable microscope [by Robert Ratford]

Robert also brought a large number of slides of lampreys, from a project of one of Peter Evennett’s students, and copies of parts 1 to 4 of “The Freshwater Microscopist” by Tony Pattinson. Part 5 has just been published.

Tony Pattinson’s booksTony Pattinson’s books

John Rhodes has been collecting particles from the air in his house and his garden in Biggleswade. To collect the particles, he uses a method devised by Derek Stevens. He uses wooden cocktail sticks coated with glycerine and pressed into a cork and left for at least 6 hours. He then washes the sticks with filtered water and centrifuges the washings, before mounting the debris in LOCA.

John Rhodes’ exhibitJohn Rhodes’ exhibit

John Rhodes’ slidesJohn Rhodes’ slides

Air pollution sampling apparatusAir pollution sampling apparatus

John Tolliday and John RhodesJohn Tolliday discussing air pollutants with John Rhodes (right)

Dave Skeet brought a trinocular Watson Bactil microscope with a Zonal dark-ground condenser, as a homage to Barry Ellam, who loved Watson microscopes and dark-ground. Dave’s slides included Klaus Kemp strews of diatoms and radiolarians, and a J. B. Howard slide of mallow anthers and pollen.

Dave Skeet’s exhibitDave Skeet’s exhibit

Dave Skeet’s slidesDave Skeet’s slides

Margaret Gillham with Dave Skeet’s exhibitMargaret Gillham with Dave Skeet’s exhibit

At a Quekett gossip in 2013, Barry Ellam showed some of his extensive collection of accessories for dark-ground, including condensers from several manufacturers, high power objectives that include an iris diaphragm, and patch stops.

Barry Ellam’s exhibitBarry Ellam’s 2013 exhibit of dark-field condensers, objectives and stops

John Tolliday was demonstrating his Laowa 25mm f/2.8 2.5–5× Ultra Macro lens, used on a Canon digital SLR attached to a WeMacro rail on a WeMacro vertical stand. He used Helicon Focus to stack the images.

John Tolliday’s exhibitJohn Tolliday’s exhibit

Mo Vaughan used his Cooke, Troughton & Simms polarising microscope and a Vickers lamp to show us slides from his collection, including his favourite forams.

Mo Vaughan’s exhibitMo Vaughan’s exhibit

Peter Sunderland, Bill Morris and Ron CushingPeter Sunderland, Bill Morris and Ron Cushing discussing Mo Vaughan’s exhibit

Alan Wood showed how he produces dark-ground illumination for his Olympus SZ4045 stereomicroscope. One method uses an inverted LED ring-light, with an inverted kitchen bowl with its base removed providing support for a piece of foam board with a central hole to let the light through.

Alan Wood’s exhibitStereomicroscope with dark-ground illumination from an inverted LED ring-light

Construction of dark-ground illuminatorDark-ground illuminator, showing (left) black disc, (centre) inverted bowl with base removed, and (right) the complete illuminator

A second method uses an LED stage plate with a disc of black paper obscuring most of, leaving just a bright ring. The specimen rests on a piece of foam board with a central hole, supported on an inverted kitchen bowl with its base removed.

Olympus SZ4045 stereomicroscope with dark-ground illuminationStereomicroscope with dark-ground illumination from an LED stage plate

Dark-ground mosquito larvaLarva of a mosquito (Culex pipiens); slide by T. Gerrard & Co.

Dandelion seedPappus of seed (achene) of dandelion (Taraxacum officinale)

Robert Ratford found an interesting use for Alan’s dark-ground lighting. He had a slide of an insect larva with the data inscribed into the glass, which is normally very difficult to read, but was much clearer with dark-ground. It starts “Trichopterous larva in tube found at Walton on Thames eating a pupa of the…”. If you can decipher the remainder, please let Robert know.

Inscribed data on caddis larva slideInscribed data on caddis larva slide

Lunch

Lynn Cardale and her assistant served us an excellent lunch, chicken (with lentils and rosemary), baked potatoes, carrots and peas, or a vegetarian alternative of lentil, red pepper and sausage bake. Followed by pear parkin pudding, apple crumble or chocolate cheesecake.

LunchLunch

Talks

DIY Stacking System for Microscopes

Gordon Brown’s talk on his Arduino stackerGordon Brown’s talk on his stacking device

Gordon Brown gave us an introduction to image stacking, which starts with a series of images at different focus depths, picks the sharpest parts of each image, and combines them into a single new image with good depth of field. Now that digital cameras are normal and stacking software is not expensive, many macro photographs and nearly all photomicrographs are stacked. However, taking a series of images through a microscope is tedious, you have to turn the fine focus knob by the right amount before taking each photograph, and sometimes dozens or even hundreds of images are needed.

Commercial devices for turning the fine focus knob and firing the shutter are expensive, and they only support wired remote controls, not the infra-red remote controls that many dedicated microscope cameras use.

Gordon designed a system based on a modified version of the Stackduino-G3 designed by Pierluigi Giorgi, where all stacking settings are controlled by an app on an Android smartphone connected by Bluetooth to an Arduino microcomputer with a custom PCB piggybacking on it. The custom PCB incorporates the Bluetooth device, stepper driver and shutter triggers. The Arduino drives a stepper motor that has 200 steps per rotation, and can do 16 microsteps per step, so as fine as 3200 per rotation. Microscope fine focus knobs usually move 100 or 200 µm per rotation, so the microsteps can be as small as 1/32 µm (0.03125 µm). The depth of field of an objective with an NA of 1.4 is about 0.28 µm, so it only needs microsteps of 1/8 µm (0.125 µm) or 1/4 µm (0.25 µm). This degree of microstepping may not be achieved in practice due to mechanical limitations, but stacking at high magnifications is a practical proposition.

Gordon gave us update on his automatic photo stacking device, which now works with cameras that use wired remote controls (such as most digital SLRs) as well as those using infra-red controllers, and now uses printed circuit boards that are manufactured in China to Gordon’s specification.

You can see much more information in Gordon’s article in the April 2021 Quekett Bulletin and in his slides here:


DIY Stacking System for Microscopes
Click the arrows to move through the slides. Click the symbol at bottom right for a larger version.

The meeting ended with more coffee, tea and biscuits before we put away the tables and chairs and set off through the country roads to the motorways.

Lynn CardaleLynn Cardale

Acknowledgements

Our thanks to Dave Skeet for organising the meeting, to Lynn Cardale for providing tea, coffee, biscuits, cake and lunch, and to the people who got out and put away the tables and chairs.

The Quekett Microscopical Club provided a grant towards the cost of this event, as part of its remit as a charity to promote microscopy.

Report and most photographs by Alan Wood

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