Which Scope for What?

[lavoisier]

Hi

I have a 127mm refractor and a 200mm reflector and was just wondering which objects would be bset for each scope? Just so I can get the most out of each and plan my observing a bit, if these skies ever clear!

Thanks

Paul

[rowan46]

it depends on your focal ratio fast scopes give wider views and thus are better for dso's slower scopes have a narrower fov take magnification better and consequently are better at planetary observing.

[lavoisier]

Sorry a bit lost there. Both are f1000mm. So does that give me an F5 for the reflector(Explorer 200P) and about F8 for my Evostar refractor?

Thanks

Paul

[GazOC]

The 127mm refractor will be hard pressed to beat the 200mm reflector on any object. Of course you don't have to collimate it or wait for it to cool down like you would with the reflector.

[dmahon]

The wideness of the view depends on the focal length of the scope - if the faster scope has a longer focal length (because it also has a larger aperture) then the slower scope would give a wider field of view.

[lavoisier]

I thought perhaps the refractor would have been more for lunar and planetary observing. Thanks to you all for taking the time and trouble to post.

Paul

[GazOC]

I thought perhaps the refractor would have been more for lunar and planetary observing. Thanks to you all for taking the time and trouble to post.

Paul

I think the gap inbetween the 2 scopes will be less when observing planets rather than DSOs.

[Abb]

I prefer my Celestron 120 Omni refractor mostly for planet and lunar observations and my 8" Skywatcher Dob for DSO's although I have used them both for everything. I find everything in my Dob to be flatter than in the refractor.

[ollypenrice]

If the 127 is an apo you might prefer the planets in that, but since they share a focal length then they don't really complement each other at all well. Both do the same thing but the Newt has more aperture. If collimated it should win all round. Time to swap one of them for something very different, perhaps??

To confirm, f ratio has no bearing on field of view. That is governed by focal length. At the same focal length the brightness will be higher at a fast f ratio because there is more more aperture.

Olly

[lavoisier]

Hmmmmmmmmm...... food for thought. Thanks Olly

Paul