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Telescopes (Astronomy)
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After years of researching and bouncing around among different candidates, I pulled the trigger today on a new telescope. As I studied it more my idea of what was ideal seemed to change a lot:
- initially just looking for the typical entry level scope...something like an 8" Dobsonian
- decided that a Dobsonian was too bulky and would primarily sit in a closet, and started looking more at SCT's. For a long period I had decided a Celestron Nexstar Evololution would be great because it has a cool wifi/tablet connection that makes it really easy to navigate the sky. For quite a while I was just waiting for this to rise to the top of my toy bucket list.
- started looking at used SCT's on CL and saw some nice bargains...a lot of people seem to buy a 10" SCT and then use it 2 times (at least they claim).
- thinking more about how I wanted to use the scope, it was going to be primarily when I go camping...we have great clear dark skies here in Arizona but not so much around Phoenix. It was also important that the wife and kids (5 and 7) can enjoy it. And I want it to last for a very very long time, not be something we junk in 10 years. So, it needs to be on the smaller side and have very little setup time...wife and kids are not going to allow a couple hours of setup/takedown time for a short viewing session. With those thoughts, I started researching refractors.
- looked hard at 4" apo's and decided it was beyond my budget for a really quality OTA (Televue, Tak, etc). Also bordering on too large for my travel desires.
- Finally decided on a TV-85 and put together 5 very good eyepieces along with a Stellevue M2 mount and tripod. Was very close to going with a wooden Televue tripod (love the look) but decided it was too big and heavy for travel and the Televue mount is just so-so. Also camera adapters, so now I have a 600mm/f6 lens for my DSLR :-).

The advantages of this setup are that it will be very portable, hence it will get used frequently (can be used for terrestrial viewing as well). It will give very good, clear, sharp views, and is great for wide views. It is very durable and takes no setup time.

The downside: Not enough light capturing ability to create impressive views of dim objects. Probably need to team it up with a large Dobsonian for long viewing sessions. Limited to about 200x magnification, so not "the best" for planetary views. Not motorized...not on an equatorial mount, so tracking at high magnifications could be an issue if I want to share the view with the kids. But this can be added later. I'm thinking that finding the objects may be just as much of the fun as viewing them, so I'm avoiding the computer assist for now.

So, what do you have, how often do you use it, and what is on your wish list?
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Re: Telescopes (Astronomy) [Dapper Dan] [ In reply to ]
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What do I use - Hubble Space Telescope (or rather, I can see the results of those that actually use the HST)
My wish list - James Webb Space Telescope successfully getting launched and in perfect working order

Hard to do better than the pros.
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Re: Telescopes (Astronomy) [Dapper Dan] [ In reply to ]
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The mount is as important as the optics. I suggest a heavy motor driven equatorial mount. Anything else will disappoint after a short time. BUT, this is not ideal for camping.

There are some decent table mounted motor driven cassegrain style scopes (celestron) that might fit your situation. I wouldn't spend big $$ for a camping scope.

*edit* when I was a kid, I move from a 12" Dobsonian to a televue refractor. Loved the televue.
Last edited by: robabeatle: Mar 28, 17 12:38
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Re: Telescopes (Astronomy) [Dapper Dan] [ In reply to ]
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I've been using 10 x 50 binoculars but am also thinking about getting a telescope. Have to do more research however.
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Re: Telescopes (Astronomy) [tigermilk] [ In reply to ]
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Agreed, which is why I'm avoiding any astrophotography ambitions. For me, there is something "real" about seeing something directly that is 2.5 million light years away that looking at a photo cannot duplicate. Photons traveled a long time and a long ways before hitting my eyeball. Even looking at the planets...seeing it makes it "real" even if it isn't as good as the picture.
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Re: Telescopes (Astronomy) [robabeatle] [ In reply to ]
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Yeah I thought long and hard about the mount. A lot of people seem to be happy with the alt-az mount for a smallish refractor like this, so I selected a well rated mount and fairly stable tripod, without being excessive (I think...we'll see). Who knows, I may wind up adding a computer mount later.
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Re: Telescopes (Astronomy) [Dapper Dan] [ In reply to ]
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I have more than just a few:

4" Takahashi FSQ
10" f/4 Newtonion
10" f/6 Newtonion
10" f/15 Cassegrain
10" f/9 Ritchey Chretien
12.5" f/9 Ritchey Chretien

All EQ Mounted with dedicated CCD cameras
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Re: Telescopes (Astronomy) [wrmattil] [ In reply to ]
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Wow. The Takahashi would have been my "step up" choice over the TV-85. Would I be correct in assuming that it is the best of your quiver for astrophotography since long exposures can compensate for it's relatively lower light gathering capability?
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Re: Telescopes (Astronomy) [Dapper Dan] [ In reply to ]
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Dapper Dan wrote:
Agreed, which is why I'm avoiding any astrophotography ambitions. For me, there is something "real" about seeing something directly that is 2.5 million light years away that looking at a photo cannot duplicate. Photons traveled a long time and a long ways before hitting my eyeball. Even looking at the planets...seeing it makes it "real" even if it isn't as good as the picture.
BTW, fun fact - I know one of the folks on the fourth Hubble repair mission. Can certainly thank that crew as well as the crew on all the repair missions for giving us continued fantastic science and photos. And later this year I hope to see JWST in person again before it gets launched next year. I saw it last year; I bet you'd like the mirror on that telescope!
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Re: Telescopes (Astronomy) [tigermilk] [ In reply to ]
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I have a 90mm short tube refractor with a non motorized EQ mount. I found it to be a good learning scope and a short tube scope with it's wider field of view made finding things easier. I haven't used it in a couple of years due to local light pollution but plan to give it ago again this summer.


Jim

**Note above poster works for a retailer selling bikes and related gear*
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Re: Telescopes (Astronomy) [wrmattil] [ In reply to ]
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What do you think is best for:

backyard viewing in an area that has some light pollution

portable enough yet useful to take travelling to dark skies

viewing in dark skies if you are lucky enough to live there

Within a budget of about $2000. Not looking for one scope for all situations just which would be best for each one?

wrmattil wrote:
I have more than just a few:

4" Takahashi FSQ
10" f/4 Newtonion
10" f/6 Newtonion
10" f/15 Cassegrain
10" f/9 Ritchey Chretien
12.5" f/9 Ritchey Chretien

All EQ Mounted with dedicated CCD cameras

They constantly try to escape from the darkness outside and within
Dreaming of systems so perfect that no one will need to be good T.S. Eliot

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Re: Telescopes (Astronomy) [Dapper Dan] [ In reply to ]
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Dapper Dan wrote:
Wow. The Takahashi would have been my "step up" choice over the TV-85. Would I be correct in assuming that it is the best of your quiver for astrophotography since long exposures can compensate for it's relatively lower light gathering capability?
,

Dan,

It'll depend on the object in question and its size. For the record the FSQ is a nice instrument, But the number of objects that would require it are somewhat limited. Think Large Nebula or Maybe M31. Or perhaps larger regions that you might be interested in. Longer focal length instruments excel in the small objects. Most notably Galaxies. And it's hard to run out of small objects. Apochromats are pricey and generally wider field type of instruments. You pay for that large flat field :)

Let me know if you have any questions
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Re: Telescopes (Astronomy) [len] [ In reply to ]
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len wrote:
What do you think is best for:

backyard viewing in an area that has some light pollution

Some Light Pollution generally means smaller, brighter objects are more easily found. Large, dim objects do not fare well in Suburban Environments

len wrote:
portable enough yet useful to take travelling to dark skies

You would be surprised on what "portable" can actually mean given sufficient motivation. Any of my instruments can fit in a typical car. However the 60 pound 12.5 R/C is more of and effort. Mount(s) are also an issue, Dobsonion mounts provide a lot of aperture. And aperture is king.

len wrote:
viewing in dark skies if you are lucky enough to live there

Generally speaking, 8 or 10 inches of aperture is best. Assuming everything else is equal. Which it almost never is. Dobsonion mounts are cheap. But they can make finding objects a challenge. Computer driven mounts save a lot of time with that. But supporting a large aperture instrument is problematic/expensive

len wrote:
Within a budget of about $2000. Not looking for one scope for all situations just which would be best for each one?

Given that price point I'd look at either 8" or 10" Dob if you like scrounging around looking for stuff. An 8" SCT with Computer controlled mount. Used can also be a way to minimize costs
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Re: Telescopes (Astronomy) [wrmattil] [ In reply to ]
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Considering used, my understanding is that mirrors oxidize and degrade in light transmission 1 to 1.5% per year. Do you believe older reflectors exhibit this and it becomes a factor in determining the value of older equipment? On the enthusiast sites it seems there are relatively more listings for older refractors than reflectors, yet I'm sure reflectors outsell refractors many times over.
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Re: Telescopes (Astronomy) [Dapper Dan] [ In reply to ]
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Mirrors do degrade over time and exposure to dust and dew can add to this degradation. However - Having a mirror recoated is a simple process and not a huge expense. However ... be aware that in Astronomy there is a group of what I call "Refractor Snobs" A Refractor is not the best instrument for everything. Aperture costs soar like you have no idea for an 8" Refractor,
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Re: Telescopes (Astronomy) [len] [ In reply to ]
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len wrote:
What do you think is best for:

backyard viewing in an area that has some light pollution

portable enough yet useful to take travelling to dark skies

viewing in dark skies if you are lucky enough to live there

Within a budget of about $2000. Not looking for one scope for all situations just which would be best for each one?

I got a used deal on a Chinese 8" F/5 tube on a HEQ5 mount/tripod, with GPS. $1000 Cdn. Then I added a couple of decent eyepieces, a boutique two-speed focuser (machined my own adapter for the tube) and more recently a 4x Tele-vue barlow and corrector. I take pictures with it using a Canon EOS T6i and do optical as well... just really getting started with it. It is pretty amazing what it can pull out with 30 second and longer exposures... but for much longer I'll need to add a star tracker.

Among the cool daytime things I've done: Capturing a sun transit of the ISS. You basically need to be within about a 10 mile band, and the transit takes about 0.8 seconds so your camera has to be running at the right time.
I also have Mercury's sun transit from a couple of years ago.

The whole thing takes maybe half an hour to set up and align, and it's portable enough to go into the trunk or back seat of a small car. Next year I'll probably take it to Idaho for the eclipse and whatever else we can see from rural campgrounds.

Our home location is about a 5 on the Bortle scale but I can usually see Andromeda with the naked eye on clear nights in the fall so I do most observing just from there.

Less is more.
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