Despite the conflict with another QMC meeting, the gathering was well attended and much interest was generated during the course of the day. In addition to the listed exhibits, several visitors brought along optical artefacts to be identified or discussed. Graham Griffin Provided a really fine exhibit of his improvisation:

Left the Patholette, right Graham (foreground explains it to Per Borjesson)

It was a much modified Basic Patholette stand . The stage had been modified to allow 1mm steps, and the body tube was horizontal with a revolving prism in order to direct the illumination. The lighting unit had been largely rebuilt. He was observing Diatoms of various species. Per Borjesson brought a Zeis Ikon camera adapter with the intention of discovering suitable camera adaptations. Klaus Kemp arrived with a copied Haeckel plate of diatoms from a publication. It was typical of this illustrators rather controversial masterpieces, full of symmetrical geometry! Klaus explained that this particular plate had inspired him to create just such a layout, but in real diatoms of the species used by Haeckel and in a similar manner with geometric lines about the vertical and horizontal planes. In dark field it was unbelievably beautiful (See opening picture above). Klaus also had some rather stunning photographs taken by Stephan Nagy of Montana using a special sub stage condenser that created brilliant effects of colour.

Dick Speight had a binocular Biolam and set out to demonstrate Abbe`s theory of microscopic resolution. One eyepiece was in place; the other contained a phase telescope in order to be able to observe the back of the objective lens. On the stage was a line object at 300 lines per mm. The Lomo special objective lens of X10 had been provided with an iris adjustment by which the numerical aperture could be altered. Another adaptation was that the mirror had been replaced with a plain aluminium sheet disk turned in Dick's workshop. At the fully open position of the iris diaphragm, the lines were clearly resolved at the eyepiece . Through the telescope The zero order of diffraction could be seen as a dull white light in the centre and either side could be seen the first order diffraction beams as bright colours. When the diaphragm was partially closed, resolution at the eyepiece was lost altogether, and at that position, the telescope only displayed the central zero order beam. The bright first order beam was no longer in evidence. The use of this 300 line grating made an excellent demonstration.

Dick Speight (foreground) explains his exhibit to Pam Hamer (the New Quekett President)

 

Peter Weedon brought a splendid old black portable Beck with the number 20226. It had recently been bought on Ebay, and was waiting to be refurbished, but in its dusty glory was not unadmired.

William Vatcher had an interesting Beck instrument for the measurement of minute degrees of depth. He also demonstrated the use of an old computer hard drive as a microscope turntable using magnetic clamping. This was a very impressive event and the performance of the bearings was noted by several as a potentially valuable development.

Fred Loxton and Charlotte set up a demonstration of a PMS box belonging to Ed. Markham. It contained lots of whole insects and really well finished slides which were very popular with all: Really a PMS mounter at his best.

 

Pam Hamer had a wonderful display of live Lichens under the microscope but also had a number of very useful and attractive publications which included a computer based key to identification. A filiar eyepiece was also demonstrated which could be used to make a precise measurement of microscopic objects.

Derek Stevens. Derek brought his Vickers M12 along and explained that Graham Griffin had recently refurbished the below stage area and organised three turrets to enable a much more satisfactory CCTV system. The camera was trained on Derek's unlimited pond life from the Little Sea at Studland where he has been recording for over a decade, and today had some excellent Desmids on show.

Derek Stevens explains his exhibit.

Brian Darnton. Had a display of Foraminifera found locally in Swanage Bay during the past year, These were accompanied by photographs taken using the Helicon Focus system.

Above - the beautiful three dimensional photographs of minute forams produced by Brian Darnton using the Helicon Focus system. Right: Brian (background) explains this to a visitor)

In addition, there was a microscope set up for displaying the polarising optical effects of various finds during the past year.

Rosemary Stevens and Margriet Darnton provided welcome refreshments during the course of the exhibition. Photos by Peter Weedon, Brian Darnton and Tony Saunders-Davies