focusing with DFK21AU04.AS

[philip57]

Hi,

I have just purchased a DFK21AU04.AS and i am having difficulty focusing on any star. I have a skywatcher ED80.

Using IC Capture to see the live view, i have focused right in and right out but to no avail. The camera does work because i have tried it on a streetlight and that was visible in IC Capture

Has anyone used the DFK21AU04.AS with the SkywatcherED80, and could give me an idea of the focusing position of this camera.

Thanks in hope someone can help

Philip

[Cornelius Varley]

You may need an extension tube to increase the length of the draw tube if you have removed the diagonal from the light path.

Peter

[riklaunim]

Refractors need some extensions as the focusers are set to focus easily with diagonals in the path for visual use.

[Photosbykev]

if you can focus on a street light through the scope i.e short distance, then it sounds like you can't get the camera close enough to the scope to focus at infinity which sounds odd to me.

With my ST80 I needed to add, not remove, about 15-20mm extension tube to reach infinity. You can check this by just holding the camera behind the scope draw tube to see if infinity is reached with the camera further back

[philip57]

Hi,

thanks for the replies

It was the diagonal, when i replaced the diagonal i could get focus again. I will need an extender if not using the diagonal.

i am trying to use WCS and this cam for drift alignment. Does anyone know a good tutorial

Philip

[ollypenrice]

An old Barlow with the lens removed makes a cheap extension tube.

Olly