by Ted Clarke, USA
I am now in remission from
myeloid sarcoma and living in an apartment. I am preparing
instructions so my grandchildren can use my microscopes when I am
gone. The modified Monolux microscope is equipped with Edmund
Scientific JIS objectives. I was curious how the resolution of the
Edmund 60X objective would compare with that of the LOMO 30X 0.90 NA
water immersion objective. My sudden move to be with my family
necessitated giving up much of my equipment, including the cable
release attachments for my digital cameras and my heavy macro stand
for supporting the cameras.
I did keep my enlarger stand
for photography with the microscopes. I modified my Olympus E330
DSLR for use with a cable release by using epoxy putty to attach a
length of 6-32 screw thread to the camera body as shown in Figures 1
and 2. My modified Monolux was used for the tests of both objectives
with the camera on the enlarger stand as shown in Figure 3. A Zeiss
Kpl 25X eyepiece was used with the LOMO 30X objective at 160 mm tube
length with a 0.17 mm thick cover glass and water immersion. The
Klaus Kemp 8 form diatom test slide was used for the tests. Nitzschia sigma was chosen as the test diatom because my earlier
article demonstrated that the striae of this diatom were just
resolved using COL.
The transverse striae were
well resolved with the 60X Edmund objective versus just resolved with
the 40X objective, compare Figures 4 & 5. The 30X objective
resolved the transverse striae to rows of dots, see Figure 6.
Figure 5. Nitzschia sigma imaged with Edmund 60X 0.85 NA in COL.
The 30X LOMO objective was
designed for epi fluorescence of biological specimens. My hobby use
of this objective is very unorthodox. I prefer to use this objective
for pond water studies without a cover glass. I found that the
spherical aberration from use without a cover glass can be corrected
by extending the tube length from 160 mm to 212 mm. I use a 16X
Zeiss Kpl eyepiece with the extended tube length. My goal is to
obtain artistic images of live diatoms, like that in Figure 7, to
share with friends.
Comments to the author Ted Clarke are welcomed.
Microscopy UK or their contributors.
Published in the May 2015 edition of Micscape.
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