Choosing a focal reducer, help please.

[spacetrace]

Hello

I have bought a WO zenith star 80mm scope with a focal length of 545mm, making it an f6.9. I would like to buy a focal reducer but I don't know how to choose the right one. The focal train is 2". Does anyone have any suggestions ?

I also have another, slightly related, question. What are the disadvantages of stepping down the imaging train from 2" to 1.25"? Does stepping down affect the image etc? I would be using a canon 1100d as I am sure the effect depends on chip size?

[ollypenrice]

Try Ian King Imaging for advice on what will work with what.

Whether or not you'll get vignetting with 1.25 filters in a given setup I'm afraid I don't know but again I'd ask Ian.

Olly