Focal Reducers

Hi, Just a quick question - Can I fit an f6.3 focal reducer to a 80mm or 100mm refractor, or are they exclusively used for SCT's?? :

Thanks, Keith..

Keith - you can certainly get focal reducers for refractors - they're not exclusive to reflectors (they're a negative barlow).

Have a lash at google to see if there's any that would suit your OTA.

e.g.

www.telescopehouse.co.uk/page.aspx?f=on&...Y8AedOGEYs7CF5zA1pHa

Cheers

Dave

A second Q on the subject, if you don't mind...

What is the benefit of a focal reducer, and how does it work?

...ok, its 2 questions rolled into 1!

Seanie.

Seanie, they are primarily used for astrophtography, but visually also, if you have a long focal length scope, they 'reduce' the focal length down to f/6.3 from say my SCT at f/10. This widens the field of view, and it takes less exposure time to shoot your target

Thnaks Dave for that link!

Keith..

To add to Keith's explaination, the technical description is that they are simply a lens assembly that messes with the light to give you a, er, shorter focal length... And they empty your bank account

Seriously, they also help to flatten the field of view - see the technical description above :

Sheesh...

Thanks guys! So simple really, but never really understood it! :idea: