Best planetary views through an F6 & F10 refractor?

[Guest]

I have been thinking recently ( you know I have because you can see sparks and moving cogs in thru my ears. Lol).

I have an 80mm f6 refractor with FPL 53 glass. I have used a good quality 2 x Barlow lens to observe planets. This Barlow doubles the focal ratio of my 80 mm. There is an 80 mm f10 ED refractor. So which of these instruments would give the better planetary view if they were mounted side by side. The Barlowed f6 or the native f10?

[F15Rules]

For planets I'd take the F10 refractor over an F6 every time.

Assuming both scopes are properly mounted, with the longer scope you have the following advantages:

- easier to get higher magnifications, with longer focal length eyepieces, for more comfortable, extended viewing, making it easier to pick up fine detail - and no Barlow needed

- better contrast leading to superior views with darker sky background

- more depth of focus, making it easier to get sharp focus "snap" at high powers

An F6 refractor is normally intended for Astro Photography (AP) or widefield, low power views. I have a nice 80mm F6 achromat which gives lovely wide, low power views, but is not at all great at anything over c x75 magnification. Your FPL53 will do better, Martin, but IMHO it won't compete with a good ED F10 doublet for observing planets - it's not what it was designed for..🙂

Dave

 

[neil phillips]

All of the above