One of the real trouble jobs in #astronomy is collimating a reflector telescope. In particular, Maksutov-Cassegrains, like the ETX90, are tricky.
Fortunately, Escher over Cloudy Nights has posted a really useful guide.
https://www.cloudynights.com/topic/391392-dont-mess-with-etx-collimation/
How good is my camera lens?
This is a series of images of an artificial star as seen by a camera lens and digital camera. They range from one side of best focus, through focus, and onto the other side of focus.
I see two errors:
1. Collimation/alignment
2. Astigmatism (probably pinched optics...bad optomechanical support)
I will disassemble this lens to investigate further.
https://www.skyatnightmagazine.com/advice/how-to-star-test-a-telescope
#Optics #Testing #Collimation #Astigmatism #Photography #Astrophotography
Stars were bright points instead of comet-like blurs. I was even able to see M13 — the grand globular #starcluster in #Hercules — though between #lightpollution and atmospheric haze, the view was low contrast but filled the field of view; I can hardly wait for better seeing! I tore down for the night happy to have the old C11 performing well and ready for some cosmic exploration. #C11 #collimation #M13 #venus #astronomy
Frustrating night last night, trying to fix a #collimation problem I (probably) introduced on the old #C11 I acquired late last year. I worked on it today in the office using a Cheshire-style tool and it *may* be close enough now to refine using starlight. Tonight's the last night expected to offer clear skies for several nights to come! Hate to sacrifice good nights to this issue but it must be resolved -- the #telescope is worthless without this fix!
