A mysterious field microscope - the Chinese TWX-1 (V)
At present one of the most typical mail questions is: "Where can I order a few of those
TXW-1 microscopes" or even "Please send the TWX-1 microscope to my address ..."
But, we are terribly sorry to confirm that at the moment there are very few merchants - worldwide -
who might have one of those micro marvels in stock.
The reasons are quite easily understood: the TWX-1 was made solely in the 1970s,
we think in the years 1971 to 1979. It was produced by the TaiYuan Optical Factory
which had no commercial objective at all. The microscope was provided exclusively
as a mobile hospital equipment to be used by the Chinese army. Top secret.
It took several decades until western specialists and microscope collectors
became aware of the TWX-1. In the years 2008-2010 a limited number of TWX-1 instruments
was offered via Ebay, only from Chinese vendors. But it remains unclear whether the production numbers
were rather low, which percentage of the instruments might have been lost or corroded over the years or
whether thousands of them might still be in possession of the Chinese army. In any case the vendors appear
to have run out of stock at the moment. As a consequence the TWX-1 must be regarded as the rarest and most
collectible field microscope worldwide - which is really bad news for the microscope amateurs
and microscope collectors all over the world.
Until now, no photos are known which might serve to elucidate the production process at the factory
and, of course, it might be extremely interesting to learn how a few western concepts
merged with Chinese production in the 1970s. It must be accepted that the TWX-1 is
far from being merely a copy of a Western product. It is not simply spy work as western cynics
might suspect - instead it appears to be an interesting synthesis of western ideas
into an independent Chinese product.
Only a few of the constructive elements probably have been inspired (or copied) from the
earlier Nikon Model H field microscope.
Among these elements are the roller type specimen holders which allow the object slides to
be moved in (visually) x-direction:
with spring and rubber roller,
serving to move the field of view horizontally,
Also the object table might be interpreted as a copy of the
Nikon instrument. On the other hand it must be noted that a dove tail based object table
slider (y direction adjustment) probably already existed before the Nikon microscope.
Furthermore, the coarse and fine focus system found at the TWX-1 appears to be an entirely new concept for
a field microscope (the Nikon doesn't have a z direction coarse focus).
Object table dove tail mechanics - all metal.
We have noted one disadvantage of the roller holder in field use.
In case the microscope is not being held horizontally it might happen that the slide is
inadvertedly moving horizontally. But normally you will not perform microscopy on the back of an
elephant or a camel, so this is rather high level criticism.
The coarse focus with its circular ramp mechanism is a typical example of military
production (costs are a minor concern ...):
Coarse focus wheel of the TWX-1 (accessible from both sides of the TWX-1)
... as seen with removed cover.
Coarse focus adjustment:
the red arrow is
pointing to the bolt which is translating the ramp path into vertical movement.
Instead of the regular iris lever the TWX-1 boasts with a luxury milled wheel which
allows a very comfortable, reliable and stable iris adjustment.
Iris with milled wheel and (blue colour) bulb-to-daylight-quality conversion filter.
As mentioned already previously, the TWX-1 is really close to
those precious James Bond gadgets and there is some danger that it might not be used
at all in order to protect it against loss or damage. For this reason we do recommend
a modern transport bag serving as an excellent protection against shock.
The TWX-1 in a modern bag, less military than the original
olive colour metail container.
Recently one of our readers sent a moss sample with nice tardigrade eggs.
We have used them in order to demonstrate the optical power of the TWX-1.
One should keep in mind that this kind of opaque globular egg is far from being
an ideal object for the light microscope. Nevertheless the result is quite okay.
Tardigrade egg (80 µm), as seen through the
45x objective of the TWX-1.
Even though the TWX-1 is a kind of opto-mechanical miracle
it must be admitted that a desktop microscope still offers some advantages in
handling. As a consequence it is no surprise that the respective photomicrograph results
in practice can be slightly superior, not so much due to optical differences but due to the
ease of handling, adjusting illumination etc.:
The same tardigrade egg as above (80 µm),
but photographed (in perfect quietness) at home, at the big desktop microscope.
We are sorry to state that it was not possible to
present the "Echiniscus finder" in this issue as announced. But we promise
that it will definitely be part of the upcoming jubilee (10 years!) issue in July.
© Text, images and video clips by
Martin Mach (firstname.lastname@example.org).
Water Bear web base is a licensed and revised version of
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