3.3 Focal Reducer

mick pinner · #1 23-06-2007, 08:32 PM

has anyone tried the 3.3 f/r on a LX200 with a DSLR, and what success or lack off did you have.

acropolite (Phil) · #2 23-06-2007, 08:46 PM

From what I have read the f3.3 adapter is for small chip use and will cause severe vignetting on a DSLR.

mick pinner · #3 23-06-2007, 09:03 PM

thanks Phil.

[1ponders] (Paul) · #4 23-06-2007, 11:22 PM

Definately not the FR you want to use with a DSLR. It is designed for using with the DSI and it's small chip. Anything over about 1/2 inch diagonal will probably show vignetting or distortion around the edges.

rogerg (Roger) · #5 24-06-2007, 11:33 AM

I don't use my F/3.3 much even with my ST7 because of distortion & vinyetting. Definitely not recommended for a larger chip than that of a ST7/webcam.

My situation is perhaps worse than the norm becuase I havea focuser in the mix, moving the focal reducer further from the mirror and exadurating the problems.

sculptor · #6 24-06-2007, 12:33 PM

The Celestron F6.7 reducer causes severe vignetting with my 22mm chip and Crayford focuser. It was bad on the Celestron 9.25", but horrendous on the 11". If I want wide flat field I put the camera on the ED80 600mm F6.7 guidescope. That gives about 3 deg field. If I want more exposure, I just do a bigger stack. Cheaper, too!