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During this
year of 2009, I was intrigued by objectives Olympus marked with a RP on
Ebay
and I wanted to know more about it. I) Material
I am
equipped in microscopy in the brand Olympus. I possess for a long time
a
microscope BHS. With the development of the sites of bids on internet,
I completed
this one by accessories and other microscopes bought in
second-hand. |
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I bought in particular in the United States a few years ago, Olympus was an inverted CK2. it is 110v but I added it a transformer 110-220V dating the passage in the 220v in France!). 
I use it
first with objectives A4Pl, A10PL for which the rings of phases were
supplied and
LWD20PL (this last one has a ring for regulation of thickness of cover
object 0
2mm). |
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Last year I
bought 2 olympus objectives: 10x
achro
RP O.N. 0,25 and To note,
the 40x is planned for a thickness of cover object of 1mm! |
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I made rings for phase corresponding for the slide channel of the original condenser of the CK2 but this one had an insufficient opening for the 40X. |
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Now at the
same time, I bought in second hand 2 whole sets Nikon Diaphot for the
contrast of Hoffman. I
so have 2 condensers Nikon of opening 0,5. |
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The one was
associated with the objectives for contrast of Hoffman: LWD20x 0,40 LWD40x 0,50 It is now my usual set on this microscope. |
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Other condenser in 4 openings in turret, serves
for do-it-yourself and in particular for this relief contrast . I made
phase rings with card board.  A brochure associated with microscopes Olympus
CK (ref 1) gave me a model to realize the rings of phases adapted to 2
objectives for this " Relief Phase Contrast ( RPC) ". It is necessary to note that the brochure
dedicated to the more recent microscopes CKX (ref 2) describes a
different technique
the contrast " Relief ( RC) " who seems very close to the contrast of
Hoffman ( HMC). Did the patents of this technique become exploitable by Olympus? I have no details of the story but my tests by setting 2 techniques are also intended to separate 2 generations of equipments. |
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2) Results
of the tests Behind my
impressions, it is these images realized with a digital Nikon
camera that show. I take classical oral epithelium cells. Pictures are all resampled for
500 pixels length. |
| 1st series (in the scale 0,5 = 2 photosites for 1 pixel in the image): | |
| Contraste de Phase "Relief phase contrast" Olympus | |
| 10x 40x |
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| 2nd series to keep the frame given by the projectif NFK2,5x: | |
| Phase | "Relief phase contrast" Olympus |
 10x |
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 40x |
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| At 40x, I also realized views in contrast of Hoffman and in interférenciel contrast but I did not find the mème field after change of microscope. | |
 40x |
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| Contraste d'Hoffman | Contraste interférenciel |
2nd test subject: always with objectives 40x, observations of a drop of liquid floating of a yaourtnature to see bacteria responsible for the processing of the milk: long lactobaciles and chainettes of streptococci, among globules of fat
| Contraste de phase | Relief phase contrast |
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| Contraste d'Hoffman | Contraste interférenciel |
| Now, 3 examples on the same line for easier comparaison: | ||
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| Contraste de phase | Relief phase contrast | Contraste d'Hoffman |
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| Contraste de phase | Relief phase contrast | Contraste d'Hoffman |
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3) Discussion The images
in RPC have globally the aspect of the contrast of phase but the halo
is
present only of the highly-rated only one. It gives a light impression
of
relief but which has nothing to do with that of the DIC. This technique
RPC seems
to me to bring little. it was nevertheless proposed recently (2007)
under a nearby
shape by a working doctor in Rumania Joerg Piper (ref. 3). It seems
that Zeiss (ref. 4) also used a nearby idea a while (Variable relief
contrasts
= Varel) before developing in 2003 a contraste
interférenciel adapted in limp blow up
PlasDIC. (Ref. 5) The
interférenciel contrast ( DIC) is much upper every time we
can use it. The
contrast of Hoffman ( HMC) is interesting with the incompatible plastic
material(equipment) with the DIC. It is credibely the current solution
Olympus These
techniques based on an oblique illumination are however interesting
because
they have only a low cost and can be implemented by amateurs handymen. The plas
DIC would credibly be interesting but it is reserved in the business
for
devices Zeiss. I wonder however if it would not be possible to realize
it with a
prism IC for reflected light? It is a new way to explore of
do-it-yourself. Daniel Nardin Please feel free to
e-mail me, : daniel.nardin@laposte.net, if you have any
questions or
comments. |
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Bibliographie, références internet : (1)
Olympus
relief phase contrast (2)
Olympus
relief contrast http://www.smt.zeiss.com/C12567BE0045ACF1/Contents-Frame/B14DDA7D7E2CA1D9C1256FB6002A5EA1 (5) Zeiss PlasDIC http://www.zeiss.de/C12567BE00472A5C/EmbedTitelIntern/Article-PlasDic_e/$File/GIT_Arcticle.pdf |