Celestron Edge HD 8 - Reducer or no?

[Ultra.Astro (Robert)]

Hi all, just wanted to get everyones thoughts on pros/cons of the 0.7x Reducer. Is it worth purchasing?

I am moving up to an Edge HD8 from a Wide field scope, obviousl ythis will come with alot of challenges however just wanted to know if the 0.7x is worth the high price.

[Dave882 (David)]

Hi Robert-not for planetary imaging but if you’re capturing dso targets I think it’s a very good idea to get a reducer. As it’s an edge scope your options are limited. The celestron is pricey, i think there’s one or 2 other options as well that may be suitable such as the Lepus one but make sure you read the reviews and don’t skimp on this cause you spend all that money on a corrected sct and then use a sub-par reducer doesn’t make sense. Just note that while it’s fairly easy to get a flat field at f10, as soon as you add the reducer to f7 it’s important to get absolutely perfect spacing etc so if using an apsc sensor you have to spend some time to get this right. Hope that helps.

[Ultra.Astro (Robert)]

Thanks Dave, have done a bit of research into it and definitely seems like a good idea for the DSOs which is what I will be mainly using it for. I would definitely get the Celestron reducer and not another brand.
Definitely keen to use it for planetary also but that's not something I have done much of yet.
When you say perfect spacing are you referring to the back focus from the reducer to the image sensor? I have heard this is a very fine line.

[Dave882 (David)]

Originally Posted by Ultra.Astro

Thanks Dave, have done a bit of research into it and definitely seems like a good idea for the DSOs which is what I will be mainly using it for. I would definitely get the Celestron reducer and not another brand.
Definitely keen to use it for planetary also but that's not something I have done much of yet.
When you say perfect spacing are you referring to the back focus from the reducer to the image sensor? I have heard this is a very fine line.

Yes that’s correct. Start with the documented figure and then adjust in small ( like 0.5-1mm) increments if not perfect.