Posts Made By: Bret Akers

It depends on which two refractors you are talking about.

So Vince, are you going to get a set of the XW's???

Kenny,

In my opinion there are 3 eyepieces that are really important in a collection.

The first one is the lowest power eyepiece that you would reasonably use. For your scope that might be an eyepiece in the 30mm to 32mm range. (A 32mm eyepiece would yield a 6.8mm exit pupil)

The second eyepiece is the common high power eyepiece that takes in account your local seeing conditions, your scope's optical quality, and whether or not the mount is driven. In my opinion it's a pain to push a dob at over about 200x. For that you're looking at something around 6-7mm (200x @ 6mm)

That third eyepiece is the one that splits the difference and finds a happy medium in both magnification and true field. Something in the 14ish mm range might be ideal.

So where am I going with this...

My suggestion: Don't bother with the barlows and look for 3 good eyepieces in the above focal lengths. It looks like you were prepard to spend about $500 for eyepieces/barlows. If that's a fixed budget, I'd suggest something like a 7mm & 14mm Pentax XL and a 30mm Ultrascopic. If you shop around you might be able to swing the 3 for about $500.

Why ditch the barlows? They add more glass into the optical train and it can be a pain to constantly switch eyepieces in and out of them. I find myself rarely using barlows unless I need/want a really high power view and I don't have an eyepiece with a short enough focal length available.

-Bret

Almost sounds like a turned edge. But that's not very common in refractors since the objective is hidden at the edges by the lens cell. What's the brightness of the outer ring like inside focus?

There's a review here:

http://www.sdaa.org/_docs/_news/2003-12.pdf

Thanks,
Bret

I haven't tried the Pentax XO's yet, so no info there. But I can comment on the TMB Monos. So far, they are the best planetary eyepieces I've seen--very sharp, very contrasty, low scatter, and virtually no ghosting. I've seen more planetary detail through those eyepieces than anything else. Yes, the eye relief is tight, especially in the shorter focal lengths, but it's tolerable. For planets, the small AFOV isn't really an issue unless you're hand tracking with a Dob.

Are they worth it? Good question? They are $200+ eyepieces meant for only a few objects. If you are a dedicated planetary observer, double star aficionado, etc., the answer is probably yes... If you're just mixing in a few planetary views while taking a break from galaxy/faint fuzzy hunting...well, you'd have to decide...

-Bret

For that scope I would buy...

32 TeleVue Plossl
24 Panoptic
13 Nagler Type 6
10 Pentax XW
7 Pentax XW
5 Nagler Type 6
8 RKE
7 UO HD Ortho
6 UO HD Ortho
5 UO HD Ortho
4 UO Ortho

Which should come in right around $2K

http://www.equatorialplatforms.com/spicaeyes.html

There's a brief thread on this subject here: http://groups.yahoo.com/group/astronomy_shootouts/messages/140