Hi,
A friend has an aged Celestron C8 and he has trouble with the star shape eg. the spikes are not centered
What could be the cause ?
Thanks Rainer
📷 image.png
Spikes are not centered
There should be no spikes for a C8 but otherwise collimation needs to be sorted by the look of the stars in the image.
andrea tasselli · Jan 7, 2026, 04:56 PM
There should be no spikes for a C8 but otherwise collimation needs to be sorted by the look of the stars in the image.
Thanks. 👍️
Now I remember that he installed a DIY heater inside the telescope near jsut in the corner between tube and meniscus holding ring.
I had the telescope here and saw some wires of this badly constructed heater protruding into the light path.
I just told him to get rid of it and install it on the outside of the tube. His scope is in a roof observatory surrounded by 4 walls and I do not understand why he has trouble with dew.
I also have a 4 wall observatory and my Mewlon never gets a dew problem.
🥶
So trop issues : spires generated by wires and a lil bit of decollimation on top.
Remove/ rearrange the wires and collimate .
Celestron C8
Hi, I am trying to help a friend with an old Celestron C8. Does anybody have a diagram of the field flatness of this telescope? Is out there a pure flattener (not reducer/flattener) for this scope? Thanks Rainer
Author has Celestron C8 with optical issues; candidate discusses same scope problem.
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