Focusing Through Deep Red Filter
Posted 29 October 2012 - 01:07 PM
Posted 29 October 2012 - 02:51 PM
I suggest making a parfocalized eyepiece (described in the link). Once you have an eyepiece parfocalized with the camera + filter, you can use it to focus on a star. I use the combination of a parfocal eyepiece and a Hartmann mask. If you found something unclear, don't hesitate to ask.
Posted 29 October 2012 - 03:26 PM
I would use a parfocalized eyepiece, etc. But the problem is that my setup is based on 2 inch accessories, such as a 2" off axis guider, 2" adapters, 2" filters, etc. (1.25" adapters gave me severe vignetting). I don't currently have any 2" eyepieces, and from my experience, they are pretty expensive.