I got some very clean A.pellucida from Klaus yesterday and made a couple of strews using Naphrax. Almost any valve chosen will show lines clearly and although the dots are difficult to see I'm sure that with an Indigo (UV) Led they'd be easily visible.

I have posted two pictures to the Don Williams photo album. One is a 1280 x 920 (8) single exposure (Quickcam) the other (9) is a stack made from 1079 AVI (640 x 480) frames using Registax 4.0

The stack shows more detail and is composed of 55 frames. The contrast of the stacked image (9) was improved by stretching the histogram slightly in Registax and the same was done, in Photoshop, for the single image (8). No sharpening was done.

The objective was Leitz Fluotar 100/1.32; photo eyepiece 12.5X Leitz Periplan Photo; Condenser Lomo 1.4 Aplanatic; Camera Quickcam Pro 4000; Immersion oil was Zeiss 518N.

Don W

Okay. I got around to testing the 60X Apo on A.pellucida.

I was unable to resolve the lines using the DF condenser. This was because the NA of the objective is smaller than the condenser and I was unable to get COL, only rather good Dark Field.

So I changed the condenser and used the Achromatic Aplanatic (1.4NA) with thicker immersion oil, because things are still very hot here. I was able to resolve the lines on AP with the diaphragm full open, the condenser racked over to 10 mm (oblique illumination), and the aperture about half way closed. I had to use the thicker oil because the condenser needs at least half a millimetre to work properly with this objective and the thin oil doesn't stay put for long.

I took a couple of pictures (Webcam) and have posted one in the Don Williams folder. Zooming in with Photoshop or Windows Viewer shows dots -- in short rows of up to about five -- here and there. I used the famous Rene slide of course and its now back in its box and locked away with my other extreme valuables.

Don W