Jump to content

1564402927_Comet2021Banner.jpg.a8d9e102cd65f969b635e8061096d211.jpg

SPC900 & BAHTINOV MASK


Recommended Posts

I use one on mine for Planets but obviously only on a bright star near the Planet, then once focussed I slew to the Planet. I do find though the 3 line pattern is a lot more skewed (the central line does not appear perfectly horizontal) with the webcam, not sure whether this is teling me my collimation is off or the webcam is not properly aligned. Always looks spot on with the 450D though.

HTH

Keith

Link to comment
Share on other sites

Using the Bahtinov mast with a webcam should work, though I found it quite hard myself once I'd got a 2.5x barlow and extension in the optical train and now tend to do it by eye.

That was trying to use a star for focusing. I've never tried using a planet and was of the opinion it wouldn't work because, as Peter said, I was sure a point source was required. Enough people have now claimed to use planets directly that I'm wondering if its true. My gut feeling is that in theory it only works with a point source, but perhaps in some situations a diffuse source only a handful of arcseconds wide might well have a margin of error too small to affect the outcome. I have done no mathematical calculations to check the idea; it's just the first possible explanation that occurred to me.

James

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.