Live Surirella Diatom - DIC video

curt0909 · Post by **curt0909** » Mon Jul 30, 2012 2:37 pm

Zeiss 40x 1.0 apo oel 160/- mJ with Reichert Diastar DIC. I was surprised this unlikely combination worked so well.

http://www.youtube.com/watch?v=BhiDjVGn ... detailpage

Mitch640 · Post by **Mitch640** » Mon Jul 30, 2012 6:18 pm

Very nice detail Curt. A 40x / 1.0? Amazing.

curt0909 · Post by **curt0909** » Mon Jul 30, 2012 7:37 pm

Thanks Mitch. It has an iris that can adjust NA from .6 -1.0 but with DIC I'm able to use it wide open with good contrast. Its amazing these sell quite cheaply on ebay. Detail in the center is much better than my Nikon CFN 40x 0.95 air but it is not plan corrected so edges are not nearly as nice as the Nikon. Its also about $300 cheaper than the Nikon

Jacek · Post by **Jacek** » Tue Jul 31, 2012 1:01 am

Beautiful video. We are constantly looking for 40X lens to DIC, which is better in your assessment of CFN 40/0.95 Nikon or Zeiss 40/1.0?

Cactusdave · Post by **Cactusdave** » Tue Jul 31, 2012 2:07 am

I have looked at several different 40x objectives using DIC 10X and 40X prisms on my Nikon Diaphot inverted microscope. I have looked for example at the Zeiss West Neofluar 40/0.75 160/0.17, the Zeiss West Apo 40/1.0 - 0.8 Oel mJ 160/- , the Lomo Apo 40/0.95 160/0.10-0.20, the Nikon Apo S DLL 40/0.80 0.17 and the Nikon UV-F 40/1.3 Glycerol immersion 160/0.17. I used a mounted test diatom for a subject. The best DIC result and best overall performance was indeed given by the Zeiss West Apo 40/1.0 oil. I believe there is a Planapo version of this lens, but I have not have the good fortune to try one of these. The Nikon UV-F 1.3 Glycerol is also very good in DIC. This is a rare beast, but I picked one up at a reasonable price, as it had some marked cosmetic damage, but fortunately seems intact optically. This lens is not Plan and is optimised for recording weak fluorescence. These two lenses outresolve the others as might be expected from their high numerical aperture. The Zeiss West Neofluar 40/0.75 performs very well in DIC, but cannot quite compare in resolution and image sharpness. The LOMO and Nikon S lenses are 'short' non-DIN length objectives and require a DIN extender to reach focus. They are excellent lenses in brightfield and darkfield applications, but not DIC. The old and little known Nikon S lens in fact gives a remarkably good darkfield image.

curt0909 · Post by **curt0909** » Tue Jul 31, 2012 2:23 am

Thanks Jacek. Right now I prefer the Zeiss 40x. I don't normally use low power objectives so I like that its oil immersion. I can switch to the 60x and 100x oil immersion an back without problem. With the nikon if you use a high power oil objective you can't switch back because you'll get oil on the lens. It has an iris which is useful for brightfield and darkfield. I made this video by direct projection to sensor. The center of the image looks fine through my nikon eyepieces. No noticeable chromatic aberration fringing. It resolves better detail than the Nikon. I haven't done any 'pixel peeping' but it appears this way to me. Set backs are its corners which suffer from moderate to severe curvature of field and chromatic aberration. It may not be noticeable on a normal head but I use 30mm ultra wide eyepieces which pushes most objectives outside their designed field of view. Nikon objectives (even E Plan) have no problem filling the entire field of view with a sharp flat image but the zeiss suffers on the outside.