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Posts Made By: Robert Howe

August 1, 2004 06:20 PM Forum: Astro-Physics

AP 130 vs. maxScope for solar viewing

Posted By Robert Howe

Hi all

I seek the optimum Coronado system for detailed solar viewing. I have a MaxScope 40, double loaded, which I like very much. The second etalon makes it possible to get a very narrow bandwidth. But I can't get it to magnify the sun the way a small refractor will, for example, magnify the moon. This leaves me in the lurch for detailed viewing of the surface of the sun.

When I take off the extra etalon, the bandwidth increases and the image gets much less compelling. So I am worried that a MaxScope 60 or 70 or even 90, single loaded, might not give me better views. Any ideas? Should I try one of these other animals, or put an etalon and Blocking filter on my AP130?

Robert Howe
Wilbraham MA


August 1, 2004 06:22 PM Forum: TeleVue

TV85 versus Maxscopes for solar viewing

Posted By Robert Howe

Hi all

I seek the optimum Coronado system for detailed solar viewing. I have a MaxScope 40, double loaded, which I like very much. The second etalon makes it possible to get a very narrow bandwidth. But I can't get it to magnify the sun the way a small refractor will, for example, magnify the moon. This leaves me in the lurch for detailed viewing of the surface of the sun.

When I take off the extra etalon, the bandwidth increases and the image gets much less compelling. So I am worried that a MaxScope 60 or 70 or even 90, single loaded, might not give me better views. Any ideas? Should I try one of these other animals, or put an etalon and Blocking filter on my lovely TV85?

Robert Howe
Wilbraham MA


August 29, 2004 08:01 PM Forum: Astro-Physics

Re: SPL-O

Posted By Robert Howe

I started to do this with a Borg binocular telescope, for which TeleVue Nagler EPs would not come far enough out to reach focus. Like Michael, I found that for smaller EPs, like TMB super monos, the O rings give added security. For larger EPs, Naglers and Panoptics, the O ring is still useful by taking the "bang" out of the EP landing in the EP caddy on my Gibralatar. So now I have 4 or 5 of these rings in my EP box.


September 3, 2004 10:51 PM Forum: Astro-Physics

130 mm telescopes compared

Posted By Robert Howe

I write to ask a simple question and to invite comment, my question being stuck near the end of this long note.

Having spent countless hours at work and at rehearsals for a musical show this week, it was a relief and joy to get away (to my backyard) with a friend and observe with two AP 130 mm telescopes for a couple of hours Wednesday (9/1/4), Thursday and tonight. The low moon was more of a problem on Wednesday and less tonight. We used a 2003 f/6 Starfire EDFS (FL 780) and a 2002 f/8.35 Starfire EDT (FL 1085), on Losmandy G11s, with Televue diagonals (having only 1 AP and wanting to make the comparison honest). We used Nagler EPs (one 22mm 2 inch, which we shared; pairs of 13, 9, and 3-6), also a pair of 19 mm Panoptics, all of which we staggered to try to approximately match magnifications. Each night we simultaneously observed the Moon (the first two nights with Meade neutral density filters, tonight without), the Perseid Double Cluster, M13, M31, 3 doubles (Polaris, Mizar, Dub-dub), and Uranus. We viewed other DSOs randomly, without necessarily comparing. Tonight only, a Stowaway f/7 with an AP diagonal, set on a Gibraltar, joined us.

Both telescopes performed brilliantly. What was interesting were the minor differences I saw. Each night I felt the double cluster to be more satisfying with the f/8.35. I could see more tiny stars and the contrast was more brilliant. Lunar craters tolerated more magnification with the 8.35 (of course!) and this telescope never gave out, not even with a 3 mm EP (350x), wheras the f/6 got fuzzy at 3 mm (260x). The contrast between light and dark on the edge of the moon was more pronounced on the f/8.35. And to my surprise, M13 and M31 were brighter with the f/8.35. All three nights, each and every time we looked.

This I do not understand. Why did we both see more tiny stars and surface brightness with the 8.35? Given equal apertures, should not brightness--a function of light grasp--also be equal? Can anyone explain this to me? Does the greater refraction of the faster telescope cost brightness, or is this a random difference between telescopes? This last explanation seems implausable, as miniscule random variations ought not to change the light-gathering enough for the eye to detect the difference--no?

On Uranus, the f/8.35 showed a more clearly defined disc and I swear I could see a greenish color. When we brought out the Stowaway tonight, the view of the almost-half moon was as satisfying as with either of the bigger 'scopes. Could not get the same degree of clarity and detail, though, even with 3 and 4 mm eyepieces, as on the big boys.

Given these observations, my preference is for the f/8.35, but if I were stuck on a desert island (say, atop Mauna Kea) with only the f/6, I sure would be a happy man. Thanks so much, Mr. Christen, for your fabulous products.

Ciao

Robert

September 15, 2004 06:57 AM Forum: CCD Imaging and Processing/Solar System

Advice for newcomer

Posted By Robert Howe

Hey all,

I've been monitoring this forum for a few weeks and am impressed by all of the really great photos. With winter skies coming, it's time to take the plunge. What would be a safe, easy to use set of CCD equipment for a beginner? My observing equipment includes first quality 4 and 5 inch refractors on a Losmandy G11 with Gemini and a Starmaster with Sky Commander tracking. I have MacIntosh computers running systems 10 and 9.5. My location is moderately dark to the south and east, moderately light polluted to the north and west. I would prefer a system that minimizes computing.

Ciao

Robert Howe

October 10, 2004 08:02 PM Forum: Astro-Physics

Travel-scope research continued

Posted By Robert Howe

Hi Guys and Gals

In a search for the ideal set of 3 or 4 telescopes, I am now working through the issue of a travel 'scope (on this forum are several of my posts on this topic). I observe about 80x a year, and have settled on an AP 130 f/8 and a Starmaster 16 inch for home use. They're fabulous telescopes.

I observe on the road only 2 or 3 nights a year. To my mind a travel telescope should be rugged and easily replacable, if not cheaply priced; or it should be useful in more friendly observing circumstances at home, thus serving two purposes. I want fine optical quality and large aperture, of course, since one of the appeals of travel is to see DSOs that don't come above the horizon in Western Massachusetts. And a silky pony would be nice, while I'm wishing...

Right now I use a TeleVue 85 refractor for travel; I am reluctant to use the AP Traveler or Stowaway which I have auditioned for travel because they are much more costly and hard to replace. The TV85 has excellent optical quality and nice wide fields (ditto the APs; the Stowaway's clarity especially blows me away), but only 85 mm of aperture. And it needs a seperate mount, one more thing to carry around; on a recent trip, I was more limited by the Gibraltar mount than by the TV85 itself, which fit nicely into an easy-to-carry soft case. At home I use the 85 for quick peeks or fit it with a white light solar filter to observe the sun in tandem with a MaxScope, but otherwise I don't use it. The Traveler is much more useful at home, but I find it too heavy to carry about and will probably not keep it much longer.

A friend suggests I buy a Questar. How does the Questar 3.5 fit in my needs? Does the small aperture limit DSOs as much as I fear it will? It's f/13 or so, will I regret having such a narrow FOV (my other telescopes are f/8, f/4.5, f/7)? Is the tiny tripod adequate? Would I be better off for travel with this, with one of the refractors or with, say, an IntesMicro MN56 (weight 11#, $800, 5 inch aperture, f/6)? Or am I best off now, with the TV 85? Has anyone used the Q3.5, the TV85, the Stowaway, the Traveler, or the MN56 on the road?

In a word, what is the finest travel scope? And is it something I would use at home?

I am posting this question on the Questar, AP, TV and Russian Optics fora. All answers will be appreciated.

Ciao

Robert Howe

October 10, 2004 08:09 PM Forum: TeleVue

Is the TV85 the perfect travel 'scope?

Posted By Robert Howe

Hi Guys and Gals

In a search for the ideal set of 3 or 4 telescopes, I am working through the issue of a travel 'scope (on the AP forum are several of my posts on this topic). I observe about 80x a year, and have settled on an AP 130 f/8 and a Starmaster 16 inch for home use. I observe on the road only 2 or 3 nights a year.

To my mind a travel telescope should be rugged and easily replacable, if not cheaply priced; or it should be useful in more friendly observing circumstances at home, thus serving two purposes. I want fine optical quality and large aperture, of course, since one of the appeals of travel is to see DSOs that don't come above the horizon in Western Massachusetts. And a silky pony would be nice, while I'm wishing...

Right now I use a TeleVue 85 refractor for travel; I am reluctant to use the AP Traveler or Stowaway which I have auditioned for travel because they are much more costly and hard to replace. The TV85 has excellent optical quality and nice wide fields (ditto the APs), but only 85 mm of aperture. And it needs a seperate mount, one more thing to carry around; on a recent trip, I was more limited by the Gibraltar mount than by the TV85, which fits nicely into an easy-to-carry soft case. At home I use the 85 for quick peeks or fit it with a white light solar filter to observe the sun in tandem with a MaxScope, but otherwise I don't use it.

How does the Questar 3.5 fit in my needs? Does the small aperture limit DSOs as much as I fear it will? It's f/13 or so, will I regret having such a narrow FOV in travelling (my other telescopes are f/8, f/4.5, f/7)? Is the tiny tripod adequate? Would I be better off for travel with this, one of the refractors or, say, an IntesMicro MN56 (weight 11#, $800, 5 inch aperture, f/6)? Or am I best off now, with the TV 85? Has anyone used the Q3.5, the TV85, the Stowaway, the Traveler, or the MN56 on the road?

In a word, what is the finest travel scope? And is it something I would use at home?

I am posting this question on the Questar, AP, TV and Russian Optics fora. All answers will be appreciated.

Ciao

Robert Howe

October 20, 2004 08:20 PM Forum: Equipment Talk

Mount/Tripod for Binocular telescope

Posted By Robert Howe

Hi all

I have a lovely binocular telescope, consisting of a pair of Borg 100 mm f/6.4 fluorite apos in a rigid harness. These give fabulous views of starfields, the moon, clusters. They would be my most-used telescopes except for being limited by the mount/tripod combination. It is in a fork mount; the original tripod is too shaky for astronomical use. I have put the fork on a nice Universal Astronomics Surveyor Tripod which allows sufficient stability to view with 9 mm Eps, but below that it gets dicey. I would like to put these puppies on a nicer mount, preferably something with capabilities for Setting Circles or even a go-to or tracking mount. Any suggestions?

I am posting this to the Equipment, Telescope Making, Astro. Binoculars and Borg fora.

Ciao

Robert Howe

October 20, 2004 08:21 PM Forum: Telescope Making

Mount / Tripod suggestions for a binocular telesco

Posted By Robert Howe

Hi all

I have a lovely binocular telescope, consisting of a pair of Borg 100 mm f/6.4 fluorite apos in a rigid harness. These give fabulous views of starfields, the moon, clusters. They would be my most-used telescopes except for being limited by the mount/tripod combination. It is in a fork mount; the original tripod is too shaky for astronomical use. I have put the fork on a nice Universal Astronomics Surveyor Tripod which allows sufficient stability to view with 9 mm Eps, but below that it gets dicey. I would like to put these puppies on a nicer mount, preferably something with capabilities for Setting Circles or even a go-to or tracking mount. Any suggestions?

I am posting this to the Equipment, Telescope Making, Astro. Binoculars and Borg fora.

Ciao

Robert Howe

October 20, 2004 08:23 PM Forum: Astro Binoculars

Mount / Tripod for a binocular telescope

Posted By Robert Howe

Hi all

I have a lovely binocular telescope, consisting of a pair of Borg 100 mm f/6.4 fluorite apos in a rigid harness. These give fabulous views of starfields, the moon, clusters. They would be my most-used telescopes except for being limited by the mount/tripod combination. It is in a fork mount; the original tripod is too shaky for astronomical use. I have put the fork on a nice Universal Astronomics Surveyor Tripod which allows sufficient stability to view with 9 mm Eps, but below that it gets dicey. I would like to put these puppies on a nicer mount, preferably something with capabilities for Setting Circles or even a go-to or tracking mount. Any suggestions?

I am posting this to the Equipment, Telescope Making, Astro. Binoculars and Borg fora.

Ciao

Robert Howe