Posts Made By: Greg Nowell

If you take the advantage of a four inch aperture over the unaided eye as a ratio (20.4), the next aperture that would give you an equivalent advantage would be an 82 inch scope.

So everything we talk about in this regard is just nibbling at the edges. Eight inches, twenty inches, what's the big deal?

Greg N

I would get the OIII first, the UHC second, the Baader "moonglow" third, and a hydrogen beta sometime or other.

This article by David Knisely is one of the best:

http://cloudynights.com/item.php?item_id=1520

Actually IMHO the UHC works on *more* objects whereas the OIII steals the show by giving a better view on some absolutely spectacular objects such as the Veil.

The Baader Neodymium "moonglow" filter is the only planet filter I've used that really and truly improves the view, particularly on Jupiter and Mars. It can be purchased from AP and is inexpensive.

Ol' timers will say the old lumicons are best (I am fortunate to have one of those) but I haven't tested enough. Anyhow there are differences among the leading brands and I would stick with Lumicon, though I have an Astronomik UHC (if memory serves).

Probably one of my most satisfying views with a filter is not the horsehead in H Beta but the California Nebula in my FS128. Really nice.

Filter ownership tips:

1. make sure the filters fit your eyepieces, Meade filters often do not
2. Be wary of filter arrangements where dropping a long eyepiece in breaks the filter
3. Two inch filters are really nice for SCTs and refractors because you put them on the diagonal and then you can use any eyepiece for a filtered view. With a Dob you either have to get 1.25" and 2" format filters (to cover all bases) or alternatively get a filter wheel.

regards
Greg N

regards
Greg N

The dob aesthetic is "an optic that works."

The apo aesthetic is "precision optic." Everything is perfect and produced by a master.

You could, in fact, put a 15 or 25% (by diameter) black dot in the center of the objective and not materially harm the image.

Refractors also have to look good.

Incidentally I own two refractors and I would be mortified if they got scratched and I like them to look good. On the other hand, I have paint flakes coming off the rear casting of my C14 and I don't give a good g-d-d-mn. Fretting over your refractor is the same idea as a gorgeous woman worrying that she is "too fat."

See the attached pic. This is pretty..... Greg N

You can post images under 500kb but you can't post links in ads, there are too many things going on like people trying to link to ebay auctions, ads in other astronomy equipment venues, and so on. It's a policy, not a question of a fee.

If you attach your pictures directly to your ad text (when prompted to do so) you'll be fine.

regards
Greg N

How you doing John, still in AZ?

In the Yahoo refractors group I posted a "how to undress a Pentax XL."

You can make 'em skinny for a bino. They don't look like much with the armature removed but it can be done. Just a thought. Don't know anyone who's done it, but they're great eyepieces.

It cannot be done for Pentax XWs.

I should probably post the pictures on astromart sometime. I do have a short article here on how to put a TV astigmatism corrector on an XW.

regards
greg n

You can go with the standard Celestron dovetails.

And if you want to go a bit higher in quality you can get the Losmandy dovetails. These come with radial mounting blocks and are usually believed to have less flexure.

You will need to get rings to go with your choices; any good dealer, such as Anacortes, Teton (which sells a lot of Maks), etc. should help you out.

One thing you will need to decide is whether you want one dovetail to which you will screw and unscrew the various rings for your various scopes, or whether, as a convenience at higher outlay, you want to get one dovetail for each scope, put the appropriate rings on it, and save hassle. Perhaps you want the Pronto to be configured to ride on the Mak.

Once you get beyond Losmandy there are alternatives such as ADM, Cassady, and a few other companies.

regards
Greg N

Here's the link to my recently posted article:

http://www.astromart.com/articles/article.asp?article_id=710

The answers to the question "why do this" are:

1. If you like alt-az, this is a cheap way to get a well machined product.
2. Alt-az is great for daytime use. I have had a hell of a time using my 4" refractor or my c8 on the Mohawk river. German equatorials are very awkward for daytime terrestrial use.
3. If you throw a super polaris in the car for astronomical purposes you can, by day, use it for terrestrial purposes, all you need is an Allen wrench.
4. alt-az digital setting circle congifurations are considerably less difficult to set up than german equatorial alignments in terms of overall accuracy. A two-star alignment buys you more accuracy in alt-az than in german equatorial mode. So for those that want to pop for dsc hardware for the super polaris, this is a potential plus.
5. The super polaris is so cheap on the used market that you can afford to get one and leave it set up in alt-az for quick set ups.
6. All that said, yes, it is possible to set up a GEM pretty quickly if you do an eyeball alignment and don't bother with all the wires for tracking etc.
7. In alt-az configuration I bet it would be very easy to make an adapter for the super polaris for binoculars.

regards
Greg N

ps. I really like these SP mounts. I had one and made the mistake of selling it. Ended up buying another one.

I've given some thought to this. I don't know about "the perfect scope" because there are so many different applications. Most of the people endorsing Newts, for example, seem not to do photography.

Rod is right about the SCT being able to do most anything. Lot of punch in those coffee cans and you stick one on a Super Polaris.

I guess what I'm getting at is that the "best scope" I've found is actually a combination of a light bucket and a refractor.

The FS128 is wonderful enough that I can envision what life would be like if it were my sole scope. I can't imagine saying "I'm not a dso guy" with an FS128 or TEC140 or other quality refractor (not to mention a 6"). There are many thousands of dsos one can look at. Anyhow life with the FS128 by itself would probably be not that much different from life with a TEC 140 by itself. I wouldn't want a six inch refractor, I think, because it would be a difficult gymnastic with the eyepiece going too high and too low. The nights with the FS128 have always been good. One of the things I like about it is that I don't bother pushing for dim stuff. I tend to "try for dim" in the c14 whereas in the FS128 I just cruise for what appeals.

But in terms of flexibility the c14+102mm refractor is a very powerful combination for visual applications. I have side by sided the FS128 and C14 on Saturn and Jupiter and while the FS128 is very impressive the C14 brings in things the FS128 can't, particularly colors on Jupiter, etc. The FS128 blows away the c14 on those gorgeous wide star fields. But it doesn't blow away the c14 + 102mm. I seem to have a genetic preference for a GEM so whatever it is would be my ideal combination it would have to be on a GEM and would be a combo scope. I do prefer rear exit for the light path so I guess I'd be looking at some kind of Mak, Cassegrain, or SCT as the "ultimate."

When I am truly old and feeble I will probably settle in with a 4" refractor, or maybe a 110mm like the one TEC has announced. Meantime the rig I have does much much more than I have time to take advantage of, and there's this "whole other rig," the Losmandy-mounted FS128, which also can do more than I have time for, so I guess I'm pretty lucky.

I did get a chance to observe through my old 9.25 which I sold to a club friend a few years ago. Man now I remember why it took me two years to get around selling that thing. I'm very reluctant to say that it was "giving up" anything to the C14 at powers of 350 to 550x although certainly the moons were brighter in the c14. A 9.25 with the new TEC110mm would probably do it for me and I could get back some cash I have tied up in other stuff. But I'd hate to give up the 14" scope's ability to "go deep."

regards
Greg N

I won't offer my opinion. I simply note that my club is associated with a program that distributes 6 and 8 inch dobs FREE to "rising star" interns.

So I was out one night with my refractor and there were half a dozen of these Orion scopes out there.

I lent out my Pentax XW10 and well after an hour had to go hunt it up again. It was a revelation to these interns what a good eyepiece was like and no one who dropped it in wanted to give it up.

regards
Greg N

2. The bird through the window using camera zoom.