A quandry

[ChrisG3484]

Hi All,

Got a question. I have noticed when I hook my webcam up to my telescope and record a video I can notice a mark across the top of the video. I have had a look on the webcam and I cannot see any marks, when I look through the scope it is ok. I have looked at the primary mirror in daylight and can see some dust on it. Wonder if I should remove the primary mirror and clean it but I am a bit worried about doing this. Any hints/tips?

Chris

[LukeSkywatcher]

Can you post a single frame from one of your movies,showing the defect?. This will give people a better chance of getting to the bottom of it. Could be a glitch in the software.

Paul

[ronin]

Suggest not. A mark on the primary does not translate to a correcponding mark on the camera sensor. To get something on the sensor you need something at the object plane (the star/nebula etc), an alternative might be the secondary. Close to the image plane so that might be the culprit. All I can think of there is that the mirror is off to one side and light is not hitting it so is lost.

However that would mean the secondary is way off of collimation.

[ChrisG3484]

Hi guys when it stops raining I will upload a still using the webcam

Chris

[Earl]

Only if a Primary is really dirty, but that i mean really bad do you clean it, it does not have a huge impact and due to design it will have dirt on it, leave well alone to be honest.