Light leakage

[beamer3.6m]

This is just for information really but I have just tried to take a dark image in daylight.

Scope cap on - tick

Rear end of scope covered (its a 130PDS) - tick

Camera well coupled to the scope - tick

Result - an almost white dark.

It is surprising how much light escapes into these scopes. The mirror end has gaps clearly and this was the initial problem but even when turning this away from the light and placing a double folder fleece over the end it still showed clear daylight after a 600 second sub.

Interesting.

[Kropster]

Are you using a DSLR?

You might get light leakage through the viewfinder.

[beamer3.6m]

Good point.

I am using a DSLR and did not think of that.

I will try black tape to block it out.

[Davey-T]

Always do my darks in the dark 

Dave

[beamer3.6m]

Always do my darks in the dark 

Dave

Agreed

But thought I had a lot of time to play with as working from home today and just stumbled across these problems.

Also the camera is far hotter than normal. BYEOS is reporting + 55 when usually an imaging run has it at about +18.