Handbook for the TRIUS PRO-694C Issue 1 September 2020
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Camera maintenance:
Very little maintenance is needed to keep the TRIUS PRO-694C in excellent operating
order, however two problems, which are common to all CCD equipment, might show
up on occasion. These are dust and condensation.
Removing Dust:
1) Dust can be deposited on either the optical window (not a big problem to cure), or
on the CCD faceplate (very difficult to eliminate entirely). When small particles
collect on the window they may not be noticed at all on deep sky (small F ratio)
images, as they will be very much out of focus. However, if a powerful contrast boost
of the image is carried out, they may well begin to show as the shadow ‘Do-nuts’
mentioned earlier. Images taken with a large F ratio optical system are more likely to
be affected by such dirt, owing to the smaller and sharper shadows that they cast. A
light polluted sky will also make these marks much more obvious. There is no great
difficulty in removing such particles on the outside surface by the careful use of a
lens cleaning cloth, ‘lens pen’, or ‘air duster’ and so you should have little trouble
with this aspect of maintenance. Dust on the CCD faceplate is a much greater
nuisance, as it casts very sharply defined and dark shadows and it entails dismantling
the camera to get rid of it! To clean the CCD you will need a good quality lens cloth
(no silicone) or tissues and some high-grade acetone or isopropyl alcohol. A very
suitable cloth is the ‘Micro-Fibre’ type marketed by PENTAX etc., and suitable alcohol
is available from Maplin or Radio Shack etc. as tape head cleaning fluid. Most
pharmacist shops will have small bottles of pure acetone. A bright light and a strong
watchmakers eyeglass will also be found to be essential.
Procedure:
1) Disconnect the lead from the camera head and remove it from the telescope.
Place it on a table with the optical window facing downward.
2) Remove the two M3 screws and the M8 nut from the camera back plate and ease
the plate out of the camera body. Unplug the fan lead from the camera PCB.
