Use of oil on exhibition slides

pwnell · Post by **pwnell** » Fri Nov 02, 2012 6:48 pm

Please tell me whether it is safe to use oil on exhibition slides? In specific, I want to use oil on the diatom slides prepared by Klaus Kent. The slides have a circular section where the mount is located, circumscribed by a sticky black sealant I think. Would the oil damage it?

His reply - which I am not sure how to interpret - was:

Regarding the use of oil, the generak rule is that if it is an exhibition slide (circle or star) then that is not designed to be viewed under oil, nor for that matter are any on a black background such as the butterfly scales.

and

You can use oil on the test plate but wipe it off with a fine tissue paper and with a slightly soapy water and tissue remove the rest, then wipe dry with a tissue. Do not use any solvents as this will make a mess of the shellac ring.

René · Post by **René** » Sat Nov 03, 2012 2:18 am

I suppose they are generally quite thick and therefore tricky to be used with short working distance oil immersion lenses.

Best wishes, René

Cactusdave · Post by **Cactusdave** » Sat Nov 03, 2012 7:38 am

In my experience the use of immersion oil does damage the type of coverslip ringing used by Klaus Kemp. Even very careful initial wiping off of the oil seems to erode the ringing cement over quite a short space of time. Obviously this damage is aesthetic rather than critical to the slide, and it doesn't bother me too much to use oil on Klaus' 8 form test slides. I would be reluctant to use it on one of his more elaborate (and expensive) exhibition diatom slides though. In any case these are mostly intended for viewing 'en mass' at lower magnification and darkfield.

Water and glycerol immersion lenses are an 'easy cleanup' alternative to oil immersion for high power. The Lomo X70 1.23 Apochromat water immersion objective with correction collar is a fine lens for looking at diatoms, though it requires great care not to crash the objective into the coverslip, as it is not spring loaded and it has a really minute working distance.

There are also several nice Nikon CF glycerol immersion objectives. I have the X40 UV-F 1.3 Glyc http://www.photomacrography.net/forum/v ... +immersion and some examples of diatom pictures taken with it and with the Lomo X70 can be found here http://www.photomacrography.net/forum/v ... +immersion This lens is not Plan but gives a very fine image and is well worth acquiring if you come across one at a reasonable price.

pwnell · Post by **pwnell** » Sat Nov 03, 2012 9:45 am

Thanks for the great responses. I will use it once or twice on the 8 form test slide but refrain from using it on the 100 form slide.

curt0909 · Post by **curt0909** » Mon Nov 05, 2012 12:23 pm

I use glycerol exclusively as an immersion even with oil designated objectives. I have a Kemp slide and have not had a problem with the glycerol.

Ecki · Post by **Ecki** » Mon Nov 05, 2012 1:59 pm

If you can get your hand on those, the Zeiss multi immersion objectives are second to none. Its 16/0,50 Imm, 25/0,80 Korr Imm and 40/0,90 Korr Imm and they work with water, glycerin, and oil. These are among the finest objectives that Zeiss has ever made.

The 16x and the 25x are pleasant to use, the 40x is a diva with only 0,13 mm working distance

but for nicely mounted diatoms that would work. If you use a drop of purified water, there will be no leftovers on the cover slip after it evaporates.

Highly recommended.

Regards
ECU