Suggestions for 2nd scope

aaron308 (Aaron) · #1 17-08-2015, 03:49 PM

I've got a bit of money to spend on some astronomy gear, and am thinking of getting a second scope to go with my 200mm f5 Newtonian (got plenty of accessories already). I've got $400-500 to play with, and am thinking along the lines of an 80-100mm achromatic refractor; I'm unsure though whether to go short focal length (e.g. ST80) for wide field views and compactness or long focal length (e.g. Skywatcher 102 f9.8). Any suggestions and experiences for a second scope to go with my reflector? Already have a mount so am just going for an OTA.

glend (Glen) · #2 17-08-2015, 05:56 PM

Optcorp has the Explore Scientific AR102 f6.5 on sale for $399 USD, pretty good value, allow about $40 for shipping.

ZeroID (Brent) · #3 18-08-2015, 05:51 AM

If you are thinking about astro-imaging later would you do better to look for a small APO rather than Achromatic ? Even visually it has to be better. Second hand might find you something worth while.

aaron308 (Aaron) · #4 18-08-2015, 10:39 AM

Quote:

Originally Posted by glend

Optcorp has the Explore Scientific AR102 f6.5 on sale for $399 USD, pretty good value, allow about $40 for shipping.

Unfortunately with the exchange rate taken into account that takes me over my $500 limit. Looks nice though!

Quote:

Originally Posted by ZeroID

If you are thinking about astro-imaging later would you do better to look for a small APO rather than Achromatic ? Even visually it has to be better. Second hand might find you something worth while.

I don't really have any plans for imaging in the foreseeable future, so I'm probably not going to factor that in. A small APO would be nice but haven't really seen any second-hand ones on offer within my budget.

mental4astro (Alexander) · #5 18-08-2015, 11:13 AM

Hi Aaron,

A 100mm f/5 achro is a ripper of an option for a second scope!

For some time I had wanted to get my hands on a really wide field scope as I have several Newts, and they all have tight fields of view (relatively). But I wanted to go really wide as my 11X70 binos revealed a totally different sky than the one I was used to.

Going really wide and rich-field is the only way to see the mottled background glow that surrounds Omega Centauri, the twisted mess of dark lanes that cut through and around M7, and the extraordinary view that is M8 and M20 and their expansive surrounds, all in the one field of view.

I tried an 80mm f/5 achro, and even though it could give me upto a 6° TFOV, I felt there still was a small lack in aperture 'lift'. So I've settled on a 100mm f/5 achro. With a 30mm 82° eyepiece it gives me a 5° TFOV, and a wonderful image punch that the larger aperture can only give.

If imaging is not a foreseeable possibility, then I can recommend a 100mm f/5 achro as a very good second scope.

Mental.

Tinderboxsky (Steve) · #6 18-08-2015, 11:20 AM

Hi Aaron,
From my perspective it is not clear just what you want to use this scope for. You are going to find the range of targets and what you can see severely restricted compared to your existing scope.
My suggestion would be to wait patiently for a good set of Astro binoculars in the 60-70mm range to come up for sale here. I think they are likely to allow you to see more and get used more then either of the refractors you are considering.
So, first step think through the range of observing you wish to do and then see what equipment gaps you have. Don't fall into the trap of thinking you have to buy a telescope simply because you have some idle money wanting to be spent. For example a good adjustable observing chair might be your next best purchase. It will allow you to see much more with your existing scope as was my experience. Similarly a good freezer suit might be the next best purchase.

Good luck
Steve

mental4astro (Alexander) · #7 18-08-2015, 11:26 AM

I like your reasoning too, Steve! Sage words

aaron308 (Aaron) · #8 18-08-2015, 11:28 AM

Quote:

Originally Posted by mental4astro

Hi Aaron,

A 100mm f/5 achro is a ripper of an option for a second scope!

For some time I had wanted to get my hands on a really wide field scope as I have several Newts, and they all have tight fields of view (relatively). But I wanted to go really wide as my 11X70 binos revealed a totally different sky than the one I was used to.

Going really wide and rich-field is the only way to see the mottled background glow that surrounds Omega Centauri, the twisted mess of dark lanes that cut through and around M7, and the extraordinary view that is M8 and M20 and their expansive surrounds, all in the one field of view.

I tried an 80mm f/5 achro, and even though it could give me upto a 6° TFOV, I felt there still was a small lack in aperture 'lift'. So I've settled on a 100mm f/5 achro. With a 30mm 82° eyepiece it gives me a 5° TFOV, and a wonderful image punch that the larger aperture can only give.

If imaging is not a foreseeable possibility, then I can recommend a 100mm f/5 achro as a very good second scope.

Mental.

Thanks, that's very helpful! Considering that the newt gives fantastic views of planets and DSOs, I think wide-field is the way to go. Do you know of anywhere to get a 100mm f/5 achromat OTA, without the mount? The only ones I've seen are bundled with an AZ3 mount, which I definitely do not need.

astroboof (Steve McN) · #9 18-08-2015, 11:35 AM

I have a returned SW f5 st120 I am thinking of selling. Tube rings and dovetail, 2" diag. Finderscope. All good. $250. Been meaning ing to classify it here or buy&sell.

aaron308 (Aaron) · #10 18-08-2015, 11:40 AM

Quote:

Originally Posted by Tinderboxsky

Hi Aaron,
From my perspective it is not clear just what you want to use this scope for. You are going to find the range of targets and what you can see severely restricted compared to your existing scope.
My suggestion would be to wait patiently for a good set of Astro binoculars in the 60-70mm range to come up for sale here. I think they are likely to allow you to see more and get used more then either of the refractors you are considering.
So, first step think through the range of observing you wish to do and then see what equipment gaps you have. Don't fall into the trap of thinking you have to buy a telescope simply because you have some idle money wanting to be spent. For example a good adjustable observing chair might be your next best purchase. It will allow you to see much more with your existing scope as was my experience. Similarly a good freezer suit might be the next best purchase.

Good luck
Steve

Hi Steve,

Thanks, I'll definitely keep that in mind. I do have some accessories I am considering, but wanted to see if there was anything a small refractor could add to what the Newt can achieve. Given I've really enjoyed the views through my 10x50 binos I think wide field is the way to go, but still weighing up options!

mental4astro (Alexander) · #11 18-08-2015, 11:46 AM

Aaron, folks like AstroShop and Andrews should have the OTA available. Give them a call to find out. You may or may not need to purchase a 2" diagonal for these, something to be aware of, and these are available at good prices too.

astroboof (Steve McN) · #12 18-08-2015, 05:09 PM

Ooops I just saw my earlier post I gave on a phone.

Now I intended to type refurbed, not returned! It has been rebuilt, refurbished by myself, an old hand at this kind of thing. the R&P focuser has had the treatment, and it is fully flocked and optically acceptable.

Just had to type this in case anyone thought the scope for the worse.

doppler (Rick) · #13 18-08-2015, 08:06 PM

+1 for the 120mm f5 achro.

Great for wide field visual, mine is usually parked on my 10' newt and is the best finderscope as I dont have a goto mount.

dannat (Daniel) · #14 18-08-2015, 09:40 PM

andrews have the 102 f5 for 429 with az3 -looking at their other ads they knock off 50 for OTA only sales -
at present the new 90x600 AZ3 seems like a good deal, will have better colour correction being slightly longer f/l & is only 329

Mokusatsu (Australia) · #15 30-08-2015, 07:36 PM

What are people's thoughts on a really big pair of mounted binoculars (100x25, say) vs the short focal length refractors being discussed here?

I'm planning on getting a pair of those big binoculars, the question is whether if I owned these whether that leaves enough of a niche to fill between the binoculars and a bigger main scope that I'd end up using another refractor?

My parallelogram mount project already pairs 10x50 binoculars with an entry level 80mm refractor and these are fun together, but if I go big on the binoculars I wonder if mounting them as a pair would be worth the trouble any more or if I should just go back to singly mounting the binoculars.