help please with bhatinov mask and image in cam

[Altair]

Hi

I guess i am being a little thick and need to buy yet more equipment to resolve this issue.

When i get good focus with the mask through my eyepiece i then insert the webcam and find i am looking at a "doughnut" on my netbook screen.. so I have to amend the focusing by hand to get a good image worth filming..

I guess I should i be using something else to make the image on my screen the same as what i see in the eyepiece?

What do you suggest?

[Dave]

Hi Altair,

If you have your Bahtinov mask already made.

Put it on the end of your scope and point at a bright star.

Adjust the webcam so that the star is very bright.

You can then focus the telescope until all the diffraction spikes are concentric.

See my demo video for what you should see:

http://www.eagleseye.me.uk/SGL/BahtinovFocussing.avi

Then you can move back to the object you want to image and start taking pictures knowing they should be in focus.

Dave

[ScubaMike]

Hi Altair,

The problem is that you are changing from the eyepiece to the webcam after focussing.

You need to focus using the mask with the webcam in place

[Altair]

Oh Brill!

Thank you both so much!

I will try that tonight - Gods willing!

Doh!