Telescope shopping!

[r4pt0r]

I'm beginning my search for a new telescope. What do you all suggest. My last one was an ok Walmart one, and I could barely see the rings of Saturn with it, but I'm looking to invest in a better one. I'm a telescope novice and know very few technical terms and have forgotten what the different types are, but I can look those up on my own.

What telescope do you recommend? Suggestions? My budget is open to future evaluation, but should hopefully be less than $400.

My only prerequisites are if Galileo could see the moons of Jupiter in the early 1600's, so too should I be able to.

Also, ease of using a camera with it would be cool, and if anyone here does that please share pics.

[Aethon]

Have you considered building your own? You can build a huge Dobsonian 10-12" including the mirrors in your own shop with some basic tools and little technical skill, for the price of a pretty crappy commercial telescope. I've got some great books on it here... somewhere (glances around). I haven't read this. It's just top o' the Google.

https://stellafane.org/tm/dob/

[indroth]

You can see the moons of Jupiter quite easily. Some people claim to be able to see Callisto without a telescope when it is at maximum seperation fro Jupiter, but I think they are imagining things. I have seen them with with a 200mm lens on a DSLR. Depending on how bad your Walmart telescope isn't, you may be able to see them as well. Gallileo had a really bad telescope when he did.

If you plan to take up astronomy seriously, a Newtonian with a manual equatorial mount is a good place to start, but it will take many nights of fiddling with the mount to see anything at all. The Celestron 114EQ may be a good option that's well within your budget.

You also have the option of going with a GOTO mount. This is more expensive, and you run the risk of becoming too dependent on the goto function instead of getting to know the sky. However, if you are looking for something easy, then a goto altitude/azimuth mount with a small schmidt-cassegrain may be the way to go. Schmidt cassegrains have the additional advantage of being long focal length which makes them great for planetary viewing.

A dobsonian is another option that gives you the best value for money for viewing, but is no good with a camera. They are also big and hard to move. I have never used one, so that's all I can tell you about dobs.

To use a camera easily, make sure your telescope takes at least 1.25" eyepieces. For deep sky imaging (eg messier objects) an equatorial mount is a must. For planetary though, anything is okay. Imaging is a long discussion in its own right.

http://www.cloudynights.com has great info.

Happy telescope hunting!

[lajoswinkler]

Have you considered building your own? You can build a huge Dobsonian 10-12" including the mirrors in your own shop with some basic tools and little technical skill, for the price of a pretty crappy commercial telescope. I've got some great books on it here... somewhere (glances around). I haven't read this. It's just top o' the Google.

https://stellafane.org/tm/dob/

That's great if he can find and afford the metallization. Otherwise I don't know how could he do it. You need a vacuum chamber and all that.

[Aethon]

That's great if he can find and afford the metallization. Otherwise I don't know how could he do it. You need a vacuum chamber and all that.

Mirrors can be bought, or made yourself.

Optics: The mirror we will use in our sample scope was made at the Stellafane Mirror Class by the author, and we certainly encourage people to make their own telescope optics. However this project can use any suitable mirror you have, be it made by you, picked up on eBay or our at swap tables, or bought from a commercial supplier. Whatever source that works for you will work in this telescope.

All you ever wanted to know about making your own mirror:

[indroth]

including the mirrors

From what I have seen of other people's homemade mirrors, the results are dissapointing for the amount of work it takes. Putting together the rest of the telescope shouldn't be too hard if you have the tools and skills though.

[PakledHostage]

You can see the moons of Jupiter quite easily. Some people claim to be able to see Callisto without a telescope when it is at maximum seperation fro Jupiter, but I think they are imagining things. I have seen them with with a 200mm lens on a DSLR.

We had a couple of discussions about this topic last winter. These are the links:

[space] My first (blurry) image of Jupiter, zoomed in 6x!

[space] I think I saw Jupiter

I posted the image below in one of them. Both were taken with a 300 mm lens mounted on a DSLR camera and both are at the same scale. At the time I took the photo, Jupiter's moons were spanning 1/3 of the full moon's diameter.

[indroth]

please share pics.

[K^2]

That Dobsonian stand instruction is great. Is there anything similar that can be built to utilize CNC for tracking? I can find good steppers and build the board and control firmware, but if you have any 'how-to's on building the mechanical parts that are precise and smooth enough to do the tracking, I'd be very interested in that.

[Aethon]

Lemme look. The one I built used a Formica like, smooth counter top material as a friction bearing. Once I got the mount right, my star tracker was an occasional thumb nudge.

Commercial Dob star trackers. http://www.astronomy-mall.com/regular/products/eq_platforms/

For the visual learner tho I'm not sure about this :

http://www.nightfirescientific.com/dobsonian-mounts.html

K^2 you should be able to do much better than 30 min. worth of tracking. Found this in a quick search.

http://www.clearskyobserver.com/index.php/component/content/article/20-telescopemaking/19-sidereal-tracking-platform

Edited July 20, 2014 by Aethon

[cantab]

Astrophotography is never easy. Planets are so small and deep-sky objects so faint that you can't get good results from a quick snapshot, you need to have the camera take images over an extended period, with the mount tracking the target through the process. So keep that in mind.

For the best views for your money, giving up any imaging capability or electronic assistance, an 8 inch Dobsonian is in budget. If you'd like a scope with the computer assistance, you can get a respectable 5 inch GoTo reflector. You might have a go at planetary imaging with that along with a webcam.

I would not recommend making your own mirror. It's a major undertaking and these days you don't necessarily save that much. Better off to get into astronomy first.

[aeTIos]

Not sure how much this contributes to this thread, but my camera can see Jupiter plus moons without any telescope:

(30x zoom, 10 seconds shutter if memory serves me correct)

I haven't tried catching Saturn on a pic yet because I don't know where to look for it ^^' Jupiter is very prominent in the winter sky so it's fairly easy to point a camera at it. I'm still planning to get an actual telescope, though, so I'll be following this thread.

Edited July 20, 2014 by aeTIos

[Koemf]

I have a Skywatcher Explorer 150PL, and I think its a nice telescope. I bought it two years ago, total incl. all accesoires cost me about €500, but you can also get great beginner telescopes for less money, which allow you to see Jupiter + moons and the rings of Saturn.

I would recommend visiting an online astronomy forum: I got a lot of help from the Dutch astronomy forum and they also recommended this telescope to me. This will also help you to get into contact with other people sharing this hobby. And I wouldn't recommend building your own telescope when you have (almost) no experience with them.

[christheman200]

Hey, go and post this on cloudynights.com

We are the largest astronomy forum on the internet, and you'll get a lot more (helpful) help.

I've built a lot of equipment, and I would suggest buying your own equipment at first. If you don't have experience with similar projects, it will take you a good number of months.

[K^2]

One more question. Is there a good place to shop for just the mirrors/optics?

[christheman200]

Tons of them.

I suggest you join cloudynights. They can give you an outline of the different mirror makers. I'm not going to give any specifics because they all grind to different levels of precision.

[Aethon]

Mirrors. I'd shop around tho.

http://www.webstertelescopes.com/optics.htm

Edit- Only the best for K^2. :^)

Edited July 21, 2014 by Aethon

[cantab]

For the smaller mirrors and lenses, I believe http://www.surplusshed.com/ are good in the USA. For example they have 114/900 primary mirrors for 30 bucks.

[christheman200]

Webster is beyond top of the line... and very expensive, definitely not what you guys need. SurplusShed is ok, but you can buy an 8 inch dob with mirror for $400, or less. Much more value there.

[GoSlash27]

You can see the moons of Jupiter quite easily. Some people claim to be able to see Callisto without a telescope when it is at maximum seperation fro Jupiter, but I think they are imagining things. I have seen them with with a 200mm lens on a DSLR. Depending on how bad your Walmart telescope isn't, you may be able to see them as well. Gallileo had a really bad telescope when he did.

If you plan to take up astronomy seriously, a Newtonian with a manual equatorial mount is a good place to start, but it will take many nights of fiddling with the mount to see anything at all. The Celestron 114EQ may be a good option that's well within your budget.

You also have the option of going with a GOTO mount. This is more expensive, and you run the risk of becoming too dependent on the goto function instead of getting to know the sky. However, if you are looking for something easy, then a goto altitude/azimuth mount with a small schmidt-cassegrain may be the way to go. Schmidt cassegrains have the additional advantage of being long focal length which makes them great for planetary viewing.

A dobsonian is another option that gives you the best value for money for viewing, but is no good with a camera. They are also big and hard to move. I have never used one, so that's all I can tell you about dobs.

To use a camera easily, make sure your telescope takes at least 1.25" eyepieces. For deep sky imaging (eg messier objects) an equatorial mount is a must. For planetary though, anything is okay. Imaging is a long discussion in its own right.

http://www.cloudynights.com has great info.

Happy telescope hunting!

I wouldn't know which one is Callisto just by looking at them, but you can see Jupiter and several Jovian moons with just a decent pair of binoculars. Shouldn't be a difficult job even with a really crappy telescope.

Best,

-Slashy

[AngelLestat]

K^2 you should be able to do much better than 30 min. worth of tracking. Found this in a quick search.

http://www.clearskyobserver.com/index.php/component/content/article/20-telescopemaking/19-sidereal-tracking-platform

I have 2 telescopes, and in few months we would start to build our observatory.

30 min tracking?? You mean just follow a star or planet, or take a picture with 30 min of exposure? If there is the second case, you dont have idea how hard is that. Even 5 min sharped picture is hard.

[indroth]

Even 5 min sharped picture is hard.

That M82 picture I posted earlier in this thread, while not the best, was from a bunch of 4 minute untracked exposures, so a 30 minute exposure is probably not that hard with tracking. My tracker isn't ready yet though, so I may be mistaken.

Edit: I did run it through a deconvolution algorithm though

Also when I say untracked, I mean unguided. There was still open-loop tracking.

Edited July 22, 2014 by indroth

[K^2]

Wouldn't it be much easier to combine multiple shots taken with shorter exposure than deconvoluting a single long exposure frame? You gain a lot more information from an extra dimension (time) than you do from a known convolution kernel.

[PakledHostage]

That M82 picture I posted earlier in this thread, while not the best, was from a bunch of 4 minute untracked exposures, so a 30 minute exposure is probably not that hard with tracking.

And there's always DeepSkyStacker or other stacking software like it that allow you to combine multiple images into a single stacked image. They don't require accurate tracking because the software automatically aligns the images based on the pattern of the stars. I was able to capture an image of comet ISON this past winter using just my DSLR camera. No tracker or telescope. I took several minutes worth of photos and then stacked them using DeepSkyStacker to reveal ISON. Stacking software basically uses statistical methods to reveal images contained within the sensor's noise, much like rolling a loaded dice lots of times reveals a bias while rolling it once does not.

Edit: Ninja'd by K^2

[indroth]

Yes, in fact an additional advantage of short exposures is that you don't saturate the image because of light pollution, so you can just stack the images and subtract the background out. The problem with short exposures is that every exposure adds readout noise which can be quite bad if you are using a relatively cheap camera (including low end DSLRs). However, it is definitely better to use shorter exposures if you don't have good tracking. The 4 minute thing was just to see how long I could make it. I am still trying to figure out my process.