I mentioned a compound microscope I had recently acquired, a couple of weeks ago. Yesterday I examined some specimens at 1008X with a 90X oil immersion objective that was finally located hiding under a couple of other items in the storeroom where all the discarded Soviet Era equipment was left to rot until the space is needed for more discarded stuff which will then rot in its place. Some people don't throw stuff out - I'm very glad to say. A very fine ABBE condenser (NA 1.4) was also in the box and after a little work is now in place under the stage.
I have come to the conclusion that the Lobo factory can certainly make optics. This 90X NA 1.25 objective, made by Lobo in St Petersburg as was the whole instrument, although only marked achromatic, is not only so, but it has a flat field as well. Very fine detail, a tenth of a micron in size can be seen clearly, right to the edges of the field. The colour correction is very good and there are no fringes or other artefacts. This objective seems to be superior to those from Carl Zeiss (Oberkochen) I used years ago. I'm going to give it a more thorough test as soon as the ice on the lakes thaws and I can lay my hands on some diatoms; they have very fine details that can be used to test microscope resolution. I can't illustrate my results - I have no phototube as yet. When I get one (from Russia) I'll fit the P30 to it and see what can be done. Don _______________ Dr E D F Williams http://personal.inet.fi/cool/don.williams Author's Web Site and Photo Gallery Updated: March 30, 2002
