Around the late 1980's a new design for a portable microscope was launched to the world: The Lensman Microscope. It was the brainchild of three English computer people and was a radical design in that it loosely resembles a flying saucer. It is circular in shape being 10cm in diameter and about 2.5cm thick, weighs in at around 250 grams and has a viewfinder sprouting from the side. There is a curved arm containing a bulb which when raised illuminates specimens from the top and when in its closed position can illuminate using transmitted light.
On the under surface is a compartment for two AA batteries to illuminate the lamp bulb, a switch to select either 80X or 200X magnification, a focusing wheel and a tripod socket. The viewfinder has a rubber eyecup which can be pulled off and replaced for left-eyed viewers. The top is flat in the centre of which is a hole through which light passes to illuminate the specimen. An ordinary prepared microscope slide is placed over the central aperture and held in place by placing a ring magnet on top. An optional accessory called a Photo Link allows you to attach the microscope to a SLR camera so that you can take photographs.
Using the instrument takes a while to get used to. The magnification is set to 80X so that an image can been seen as relatively low power. When the switch is changed to 200X the optics are not par focal meaning that there is a lot of turning of the quite-difficult focusing roller to bring the image in to sharp focus. The lamp switch has two settings which gives you low and high illumination which is quite nice. It is light in weight and therefore easy to handle for lengthy periods and it fits nicely into the hand although you need both hands to use it properly.
The quality of the images are at best reasonable but not good enough to take photomicrographs which can be done using the Photo Link accessory. For the new price I feel that it does not offer value for money. I have compared it to the small battery illuminated, plastic, pocket, 'toy' microscopes that are sometimes seen in photographic shops and pharmacies, but which don't look like the 'usual' microscope and find that the image quality is slightly lower than the Lensman but at a much cheaper price.
I have seen a few Lensman microscopes on the secondhand market but they are still asking around the £120 mark which I still think is excessive. Prices like these are OK for collectors but for the serious user I would save up and purchase a better instrument such as the Swift FM-31 and Tiyoda portable or even a proper biological microscope with monocular eyepiece and a set of normal objectives and mirror. I know this latter instrument cannot be held in the hand but you can always find a suitable table or resting spot.
Comments to the author sent via our contacts page quoting page url plus : ('mdingley','')">Mike Dingley
Editor's note: Two other Micscape articles related to portable microscopes are " My Favorite Microscope" by Don Bruce and " Microscopy On The Move" by Dave Walker.
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