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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12515
Loc: Cumberland, R I , USA42N71.4W
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Quote:
I do not want to use GOTO or GPS (The Hunt vs. The Trophy). However, I do want to learn about mount dials, scales, and such. Can you recommend a source?
here's a start.
Plotting Deep Sky Objects
Plotting Summer Objects
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Wes James
Carpal Tunnel
Reged: 04/12/06
Posts: 2423
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EdZ-
The first link "Plotting Deep Sky Objects" is a dead link.
Wes
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12515
Loc: Cumberland, R I , USA42N71.4W
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fixed
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5303
Loc: San Francisco Bay Area, Calif...
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Here is a Lapides modified Takahashi Teegul mount on an Astro-Physics hardwood tripod. It can easily handle my 100mm f/8 Tak FC-100. The OTA in the photo is an AP 92mm f/7 Stowaway.
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5303
Loc: San Francisco Bay Area, Calif...
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A closer look at the mount.
When I want to use my 4" Tak all I need to do is switch tube rings. The larger Tak clam shell tube ring fits the mount beautifully.
The tube ring holding the AP Stowaway is a Tak FS-78 ring.
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BobinKy
scholastic sledgehammer
Reged: 04/27/07
Posts: 930
Loc: Country road
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Rich, thank you for your additional replies that are packed with suggestions for my viewing goals.
. . .
I am very interested in the photos of the AP 92mm f/7 Stowaway on the Lapides modified Takahashi Teegul mount and Astro-Physics hardwood tripod. That looks like a very nice setup.
The AP 92mm f/7 Stowaway has received nice reviews, including these archived comments on another forum.
I have read some very good things about Astro-Physics products. However, they do seem to be difficult to obtain--even if one has the required pocket change.
I am considering a new scope of similar size from Stellarvue SV90T. I have read everthing I could find through Google. However, I would appreciate hearing your comments if you have had the opportunity to see this scope in the field.
. . .
Regarding a mount--now I use a Bogen 3246 tripod / 501 head for my binoculars. As you know the 501 fluid head is a altazimuth mount. I have come to enjoy this setup. I am wondering how the 3246/501 (13 lbs maximum load) would work with a 90mm reflector like the SV90T (10 lbs without eyepiece/binoviewer)?
Even if the 3246/501 provides firm support for the SV90T, I still want to acquire a mount dedicated to the refractor so I can have both binoculars and refractor viewable side-by-side.
. . .
On the altazimuth side of the mount decision, I am considering the Stellarvue M3 and aluminum surveyor's tripod. Why? I guess because it is on the same webpage as the SV90T scope--and I really have not researched other altaz's. Again, thank you for your photos of the Takahashi Teegul mount and Astro-Physics hardwood tripod, which I plan to research.
Altaz seems to be a nice way to hop among the planets and bright stars--to boldly go where my eyes have never gone. 
. . .
And then, there is the desire to go equatorial. To sit in my den, atlases and observing guides spread across the desk, plotting and planning the RA and Declination for my next evening of viewing--and recording all of the numbers and decimal points in my personal sky notebooks.
You recommended the Losmandy GM8 without GOTO. The GM8 looks nice--but another pocketful of change. Can you recommend any other equatorials for comparison sake?
. . .
Rich, thank you again for your continued interest in this thread.
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Bob
38° Kentucky, USA
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12515
Loc: Cumberland, R I , USA42N71.4W
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Bob, I think perhaps you ought to step back and determine what your budget is going to be. If you intend to purchase some of the stuff you've been talking about here, you need about $10,000-$15,000. For a beginner in telescopes you may be getting in way over your head.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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BobinKy
scholastic sledgehammer
Reged: 04/27/07
Posts: 930
Loc: Country road
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EdZ--
Thank you for that jolt of reality. And yes, I have decided to stay within a $10K budget over the next three years, which is about what I have spent in the last two years in binoculars, accessories, books, trips, and such. Particularly the books--they have a way of moving the expenditures up. And now, with the price of gas and road trips to dark sites, amateur astronomy can become an expensive hobby.
A few months back, on a very rainy night, I attended an evening program on Saturn at the Cincinnati Observatory. The speaker began the program by saying, "To come out on such a thundering night, all of you must be committed, or should be committed." The accompanying spouses did not chuckle. 
. . .
But what cost do you put on a hobby? How much do hunters and sports fishermen spend on their hobby? How much do collectors of classic cars spend on their hobby and maintenance? What do horse enthusiasts spend on trail rides, quarterhorse meets, feed, and the visits from the horse doctor? And the outdoor motors for ski boats are definitely not cheap.
. . .
And the hours we spend.
EdZ, you posted some fantastic pages from your star books demonstrating how to calculate and post RA and Declination of target objects close to bright stars. Fantastic. Absolutely fantastic. I stayed up all night, on Thursday night, studying the link you posted: Plotting Deep Sky Objects. I copied your chart into a Word file and enlarged the graphic. I placed my copy of Sky Atlas 2000.0 on my desk and followed your instructions word by word. Fascinating. I repeat fascinating. It is all right there on your star chart. I guess you made the page from a color copy of Sky Atlas, or cut up an actual Sky Atlas and punched 3-ring holes. But, however you did it, there it is, a reference for moving from a bright star to various targeted objects with an equatorial mount. Fascinating.
But, for you, this came at a cost of hundreds of hours over the months and years this research must have taken.
Fascinating.
. . .
And when we check out of this life and family and friends file past the coffin, what will become of our hobby toys?
. . .
Yet, there is something that draws us to optical hobbies like astronomy and birding. What are we seeking?
For me, I am trying to articulate this for my family and friends—and for myself. Like I said in a post in the Binoviewers forum: This is one of the finest things I have found. But I guess the same can be said of boating enthusiasts or fisherman. For them, those guys who spend every spare minute on the lake, their hobbies are important as well.
. . .
Deep thoughts.
I gotta go mow the yard!!!
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Bob
38° Kentucky, USA
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5303
Loc: San Francisco Bay Area, Calif...
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Hi Bob,
Thank you!
If you find a scope that's not too big and heavy, I think this little modification would work well with your 501.
http://www.homebuiltastronomy.com/stool/EasyAltAzMountModification.htm
A telescope OTA that should be easy to find and not too much money is the Takahashi FS-102 f/8.1. It is out of production but I think they should be easy to find. They have very nice optics and mechanics. I've had the older brother of the FS-102, the FC-100 f/8 since about 1990. I love that scope. It very satisfying views.
A less expensive mount than the Losmandy GM-8 is the Orion Sky View Pro. It's a lot of mount for the money. It has a 20 lb instrument load rating.
Maybe tonight I'll give my setting circles another try. I'm so used to star hopping I seldom bother trying to use setting circles.
The best bang for the buck is a good single tube Dob. Several of the guys in our club have 8" and 10" Orion Dobs. They really perform well. Some of them have the model with digital setting circles. One thing, they can be up and observing much faster than I can with my EQ mount.
If you like 8" of aperture and want a GEM you could get an 8" SCT on a GEM.
All the best,
Rich
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5303
Loc: San Francisco Bay Area, Calif...
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Several years ago I got into birding so that I could play with my binoculars on cloudy days. The birds are amazing and it's fun getting out with a bunch of people who really know what they are doing. I end up seeing twice as many birds when I tag along with our local Audubon group. A few of the other birders are also amateur astronomers
Rich
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5303
Loc: San Francisco Bay Area, Calif...
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Thinking of telescopes again, for $1k you can get a good 8" or 10" Dob, some nice eyepieces, a red dot finder, charts, and a nice observing chair.
The views through an 8" or 10" of globular clusters will be much more exciting than in a 90mm or 100mm scope. You will see more structure in galaxies, if you use the scope in reasonably dark, transparent skies.
Rich
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mercedes_sl1970
member
Reged: 12/02/05
Posts: 66
Loc: Canberra, Oz
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Quote:
Hi Bob,
Thank you!
If you find a scope that's not too big and heavy, I think this little modification would work well with your 501.
http://www.homebuiltastronomy.com/stool/EasyAltAzMountModification.htm
A telescope OTA that should be easy to find and not too much money is the Takahashi FS-102 f/8.1. It is out of production but I think they should be easy to find. They have very nice optics and mechanics. I've had the older brother of the FS-102, the FC-100 f/8 since about 1990. I love that scope. It very satisfying views.
A less expensive mount than the Losmandy GM-8 is the Orion Sky View Pro. It's a lot of mount for the money. It has a 20 lb instrument load rating.
Maybe tonight I'll give my setting circles another try. I'm so used to star hopping I seldom bother trying to use setting circles.
The best bang for the buck is a good single tube Dob. Several of the guys in our club have 8" and 10" Orion Dobs. They really perform well. Some of them have the model with digital setting circles. One thing, they can be up and observing much faster than I can with my EQ mount.
If you like 8" of aperture and want a GEM you could get an 8" SCT on a GEM.
All the best,
Rich
I can also vouch for the Rob Nabholz adaptor. I made one of these for an 80mm F7.5 on a Manfrotto 190D tripod. So simple and it works brilliantly.
Andrew
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BobinKy
scholastic sledgehammer
Reged: 04/27/07
Posts: 930
Loc: Country road
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Thanks everyone for your suggestions.
. . .
Despite the enticement of some really nice APO refractors and the benefits of GEM mounts, I have decided to start my entry into telescopes with the Discovery PDHQ 15" f/5. The scope will be delivered in 4+ months.
In my mind, I kept switching back and forth between the SV90T refractor and the Discovery reflector. I was even considering purchasing both in year one. However, the pressure for a decision came when some unexpected home repairs limited my choice to only one scope in the first year. I chose to go deep with a 15" reflector.
My age was another factor weighing upon my decision in favor of the 126-lb split tube 15" over the much lighter refractor. I will turn 59 this fall and I think at my age I will be able to use a two-wheel dolly to move a larger scope from inside my house to my driveway. However, in a few years a larger scope may be beyond my physical abilities. So I want to start out with the heavier scope while I still have my strength and agility. Later, when it gets to be too much for me, I will probably donate it to a nearby astronomy group.
Regarding eyepieces, I have decided to begin with the line of Pentax XWs. I will probably purchase two or three this first year. As you know, the XWs are not cheap, but I have read some outstanding reviews of them.
. . .
I use SkyTools 2 observation planning software and a few days ago I programmed the Discover 15" and the full line of XWs into the custom sky simulation option, as well as the binoculars I currently use for night sky viewing. By doing this, I can select a viewing target such as M3 and toggle between the various scope and bino custom screen views with the program's interactive atlas. Although it is just a computer graphic--and not the real night sky--I must say that I like what I see as I move through the progression of the following sky simulation views. Progression of SkyTools 2 Simulation Views of M3
Fujinon 7x50 (7.5° fov)
Pentax 10x50 (5.0° fov)
Fujinon 16x70 (4.0° fov)
Garrett Signature 22x85 (3.0° fov)
Discovery 15" - XW 40 mm (48x, 88.2' fov)
Discovery 15" - XW 30 mm (66x, 66.1' fov)
Discovery 15" - XW 20 mm (95x, 44.1' fov)
Discovery 15" - XW 14 mm (136x, 30.9' fov)
Discovery 15" - XW 10 mm (190x, 22.0' fov)
Discovery 15" - XW 7 mm (272x, 15.4' fov)
Discovery 15" - XW 5 mm (381x, 11.0' fov)
Discovery 15" - XW 3.5 mm (544x, 7.7' fov)
Discovery 15" - XW 5 mm with 2.0 powermate (762x, 5.5' fov) Along the same progression thinking, I also developed two more charts that may interest readers of this thread. Progression of Limiting Magnitude
(night sky 5.6 NELM)
Calculated using Bradley Schaefer’s Limiting Magnitude Online Calculator
Fujinon 7x50 (9.4)
Pentax 10x50 (10.1)
Fujinon 16x70 (11.0)
Garrett Signature 22x85 (11.6)
Discovery 15" - XW 40 mm (13.6)
Discovery 15" - XW 30 mm (14.2)
Discovery 15" - XW 20 mm (14.8)
Discovery 15" - XW 14 mm (15.3)
Discovery 15" - XW 10 mm (15.7)
Discovery 15" - XW 7 mm (16.1)
Discovery 15" - XW 5 mm (16.4)
Discovery 15" - XW 3.5 mm (16.5)
Discovery 15" - XW 5 mm with 2.0 powermate (16.5)
NOTE: SkyTools 2 provides magnitude options in the sky simulations. The default produces magnitude viewing that is less than the limiting magnitude reported above. For example, the SkyTools 2 default for the Discovery 15" - XW 10 mm is mag 14.8. This can be adjusted +/- to approximate the actual limiting magnitude viewed in the eyecups on a given viewing night.
Progression of Exit Pupil
Fujinon 7x50 (7.1)
Pentax 10x50 (5.0)
Fujinon 16x70 (4.4)
Garrett Signature 22x85 (3.9)
Discovery 15" - XW 40 mm (8.0)
Discovery 15" - XW 30 mm (6.0)
Discovery 15" - XW 20 mm (4.0)
Discovery 15" - XW 14 mm (2.8)
Discovery 15" - XW 10 mm (2.0)
Discovery 15" - XW 7 mm (1.4)
Discovery 15" - XW 5 mm (1.0)
Discovery 15" - XW 3.5 mm (0.7)
Discovery 15" - XW 5 mm with 2.0 powermate (0.5) . . .
Again, I want to thank everyone for their guidance through this transition from (a) binocualars to (b) binoculars and telescopes.
--------------------
Bob
38° Kentucky, USA
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5303
Loc: San Francisco Bay Area, Calif...
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Hi Bob,
That is certainly a nice size. Why Doscovery brand rather than Starmaster or Obsession?
Thanks,
Rich
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BobinKy
scholastic sledgehammer
Reged: 04/27/07
Posts: 930
Loc: Country road
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Quote:
Why Discovery brand rather than Starmaster or Obsession?
Budget. 
I want to keep my total telescope expenditures under $10,000 during the next three years. Future purchases will be: Year 2009 -- Binoviewer system and extra eyepieces
Year 2010 -- APO refractor and GEM mount
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Bob
38° Kentucky, USA
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5303
Loc: San Francisco Bay Area, Calif...
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Thanks, Bob. I've had some fine veiws through Discovery scopes. The Pentax XW eyepieces are very nice. I use the older Pentax SMC-XLs.
I find binoviewing very helpful for lunar and planetary observing, but I don't use a binoviewer often for deep sky work.
The non goto Losmandy mounts (G11 and GM-8) give a lot of mount for the buck.
Rich
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BobinKy
scholastic sledgehammer
Reged: 04/27/07
Posts: 930
Loc: Country road
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The Discovery 15" f/5.0 split tube telescope arrived in 45 days. I feel quite fortunate since many Discovery users experience longer wait times for a Discovery telescope manufactured in the USA.
My cash flow was not prepared for the early delivery. Therefore, I had to wait to order eyepieces and such. Since I rambled in this thread about eyepiece selection, I thought I would report on my eyepiece decision.
I ordered Pentax XW 30mm
Pentax XW 10mm
Pentax XW 5mm I should receive these next week.
Then it will be on to learning about collimination of Dobsonian telescopes. I am thinking about purchasing the Collimating Eyepiece from Orion.
--------------------
Bob
38° Kentucky, USA
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desertrefugee
professor emeritus
Reged: 08/06/07
Posts: 515
Loc: Arizona
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As a wise man once said, "Great Caesar's Ghost!"
This is probably the single most informative, all-encompassing thread I've read on CN in a long time!
Although much has been covered, I must confess that EdZ has suggested something so simple, so obvious, yet so profoundly empowering, it bears repeating. (He actually suggests it in his linked 2003 article "Plotting Deep Sky Objects").
Rather than calculating setting circles from scratch for a particular target, simply calculate RA and DEC offsets from a nearby bright object!
Brilliant!
What the heck? Have I been living in a cave? Has this simple, obvious technique been around forever?
Wait, I've never used setting circles, I always starhopped. But, you can sure bet I'll be trying this method - coming soon to a dark sky near me.
Thank you Ed - and everyone else who's contributed to this outstanding example of CN value.
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"Look now upon the River of Heaven, Sky-Road of the Immortals, White with the star-frost of a billion years".
-Darrell
Reflectors (114, 150, 254mm), Refractors (60, 76.2, 80, 120), MCT (125), too many Binoculars
Cave Creek/Carefree, AZ
Edited by desertrefugee (09/21/08 10:47 AM)
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