Posts Made By: Greg Nowell

A widefield, choose one:

Pentax XW40*, Pentax XW30***, Pan Optic 35mm, Pan Optic 41mm**, Nagler T 31mm, TMB Paragon or other inexpensive wide field (visit University Optics).

*=my #1 choice, **=#2 choice, ***=#3 choice

You will need a 2 inch diagonal, if you don't want to get a two inch diagonal delete the above and get a Pan Optic 24mm which offers the most field available in 1.25" format.

For higher magnificiatons: a barlow, I like the Vixen DX, to be used with your 1.25" eyepieces (unless you feel like buying a two inch barlow with an adapter).

Edmund RKE 28mm (delete if you go with two inch wide field options and add 21 mm RKE)
Edmund RKE 12mm
Edmund RKE 8mm

(sold only by Edmund Optical, but available used on the 'mart)

That would be a four eyepieces, and a barlow. Three RKEs will cost $195 new and about $135 used. The wide fields will run $350 to $550 depnding on what you get. Someone will invariably recommend UO orthos, I like them, but I prefer RKEs.

Good luck,
Greg N

Roland Christen said:
The guy is recommending that I view the Milky Way with a pair of binos. He's a riot. We live in the Milky Way. Chances are that if you stare at a starry sky on a clear night ALL YOUR GOING TO SEE IS THE MILKY WAY!

By gum, I think he's got a point! (also I've never agreed binos are a good starter instrument: too hard to hold, and by the time you get 'em mounted on something usable, you might as well get a Star Blast)

Greg N

The Leitz 88 degree 30mm eyepieces is a nice two inch focuser that is comparatively light weight for what it does. It is expensive.

But it is a non-Meade, non-TV, non-Celestron, non-W.O. option and it isn't made in China.

regards
Greg N

Contact Don Rothman:

http://astronomy-mall.com/astro.parts.outlet/

He maintains inventories of a lot of older equipment. You can try an astromart ad first. But Don maintains the inventory himself so he's got money in it and needs a higher return than someone selling as a private party.

Greg N

You don't want to use a 2" focuser with a 4.5" Newtonian. The Newt is just good enough to provide passable field illumination for a 1.25" eyepiece. It can't pump enough light into a 2" eyepiece. If you make the secondary bigger to do that you don't gain much as it turns out. (I played with the secondary sizing program on the S&T web site, SEC)

Good luck with the scope, but for 2" eyepieces you'll want to go up to 8" OTA.

Greg N

Here's pic #2

Leather has been the clutch pad shipped in the Losmandy Titan series for several years now. (it is also used as an all-temperature clutch).

Greg N

One of the issues not mentioned is that you may have some kind of secondary or even primary mirror flop. You can have the star collimated in one part of the sky but when you swing to Jupiter the gravity shifts. So when you say the scope is collimated with concentric stars (a very positive sign) do a check on Jupiter's moons (throw them out of focus like you would a star and see whether you get a good donut: the moon must be in the center of the field).

Your fuzzy Jupiter sounds exactly like what I was seeing with extremely bad collimation. In that circumstance, stars appear flared.

Secondary mirror flop is usually due to some looseness in the screws or the ring that attaches the secondary housing to the corrector.

Primary mirror flop is harder to deal with.

An optical defect that is found in your generation of C11 is called "print through." Put the scope on a very bright star and throw it out of focus on either side at high power (say, a 5 to 8 mm eyepiece). If you see 8 spikes in four pairs of two (each pair is parallel) then you have print through and that is in fact a dog meat SCT. Production practices have since been changed to eliminate this defect.

good luck

Greg N

I've owned some Russells and consider this review to be "bordering on farce." In any case the Russells are good starter eyepieces, but I think Q series from Orion or other cheap Chinese are probably just as good. I do like the Delrin though. I'm not sure why we need steel.

The reviewer--like many--appears to be unaware that the eyecup on the XWs is adjustable. So if you're having problems with finding the right eye placement it's likely you haven't taken time to set the eyecup where you want it.

The main thing I remember from my Russells is about eight images of Jupiter bouncing and skidding around my field of view.

Still I loved those eyepieces, and my Rinis, when I got them. I started by eyepiece Odyssey at the bottom!

I'm not sure why we're testing center of fov sharpness in an achromat, since the light can't all come to a focus point. It would be less noticeable at low powers, of course, but the point is that in an achromat the Pentax probably *can't* open up some distance in this category because the input is already fuzzed, from the scope, beyond the tolerances of the eyepieces.

Anyhow the point about such a review is not whether it is or is not done well. What is amazing is that it is done at all.

Greg N

Now I'm going to show you the two Foucault tests. This was done using a video camera set to capture the Foucault image; a standard digital camera was used to capture the video picture. I think Bob set it at 1/25th of a second, and used a tripod. The point being you have to be slower than the sweep of the video to avoid weird effects.

As you can see, the Valle Marinaris really does look like a valley in these pictures. But the Foucault is set to show differences in height, and undoubtedly the effect is an optical illusion. I think these are actually thick wrinkles.

Greg N