EP question mainly for Steve...

[The Warthog]

but if anyone else wants to put their two cents worth (1p) in, jump in!

I have an f8 scope, and want an f9 or f10 refractor. In selecting eyepieces (talking the long haul, now, not purchasing tomorrow,) would you suggest different types of eyepiece for different focal lengths? In other words, does a WA ep make more sense as a 32 - 40mm ep than a 9mm, and does a Plossl work better at shorter lengths? For that matter, what ep gives good eye relief, FOV, and contrast at short focal lengths?

If I am planning out my ep case for a couple of years from now, should I think of buying just one type, or are different types better for different mags?

Also, do some eps work better with shorter f/l tubes?

Thnaks, eh?

[GazOC]

WH,

If you want an EP that gives good eyerelief, wide FOV AND works well in a short focal ratio scopes then youre going to have pay a fair bit of money. If you drop the last criteria the price can drop pretty considerably.

Also don't confuse focal length with focal ratio, it's the ratio that is the more important in this case.

Gaz

[lunator]

WH

welcome to the eternal conumdrum of what EP's to buy.

The F10 is a medium to long focal ratio that should be a good compromise of wide field vs magnification.

I would get a decent wide angle eyepiece say 32mm and a 9mm and if you combine it with a good quality Barlow you will have a good spread of magnification and FOV.

This advice comes at the cost of 1p but I am running a special offer of a 1p refund at the moment.

Cheers

Ian

[The Warthog]

WH,

If you want an EP that gives good eyerelief, wide FOV AND works well in a short focal ratio scopes then youre going to have pay a fair bit of money. If you drop the last criteria the price can drop pretty considerably.

Also don't confuse focal length with focal ratio, it's the ratio that is the more important in this case.

Gaz

Uh, yeah, but the focal ratio question was a sorta separate issue. I'm thinking Dob once I get the refractor I'm looking for. I want a refractor for planetary and lunar stuff, but since I can't afford an apo, I want a long focal length one. With that desire stisfied, if I can get an 8" or 10" Dob, I'll drop the Newt like an ugly girlfriend. Then I'll have an f/5 or f/6 scope to deal with, and possibly a new set of eps for optimum performance.

It's easier to buy accessories for your hobbies, you know. I have replaced everything on my bike except the frame, and my dear lady is only vaguely aware, but If I got a new bike, well, she'd clue right in. Same with the scope, she knows I've bought stuff, but not how much. It's at least twice what the scope cost me, so far.

[GazOC]

It's just you mentioned focal length a couple of times in you first post when it wasn't really an issue where the quality/type of EPs were concerned...maybe I got the wrong end of the stick.

[mark RD]

Heres my 1p....what do I get for it then??? :lol:

A penny sweet

Mark

[The Warthog]

It's just you mentioned focal length a couple of times in you first post when it wasn't really an issue where the quality/type of EPs were concerned...maybe I got the wrong end of the stick.

Well, actually, it's what I handed you.

[FLO]

I have an f8 scope, and want an f9 or f10 refractor. In selecting eyepieces (talking the long haul, now, not purchasing tomorrow,) would you suggest different types of eyepiece for different focal lengths? In other words, does a WA ep make more sense as a 32 - 40mm ep than a 9mm, and does a Plossl work better at shorter lengths?

The good news is - things get easier as you increase the F ratio because the light cone enters the eyepiece at a narrower angle. Fast scopes (f5 and less), with their short, wide-angle cones need top quality eyepieces whereas slow scopes (above f8) are much more forgiving.

For that matter, what ep gives good eye relief, FOV, and contrast at short focal lengths?

In a word - Vixen/Orion Lanthanums (OK, two words!) or any other ep that essentially has a barlow built into the design.

http://tinyurl.com/7ktcn

If I am planning out my ep case for a couple of years from now, should I think of buying just one type, or are different types better for different mags?

You cant go wrong with one SuperWide eyepiece about 30mm (2" if your scope will support it), a good quality Plossl around 25mm and a Plossl or Orthoscopic about 9mm. Adding a barlow will give you an even wider spread of magnifications. (Be sure to buy from a dealer with a good returns policy as the only way you'll know whether it suits you is to try it).

Also, do some eps work better with shorter f/l tubes?

Yes.... Expensive ones!

Written in haste,

Steve

[The Warthog]

Thanks very much, Steve. I was thinking along the right lines, then, and you've clarified my thinking very nicely.