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Telescope Vs. Binocular

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Eric DeCamp
Eric DeCamp's picture
Telescope Vs. Binocular

I am currently browsing the internet for either a new pair of affordable binoculars ($300 max), or affordable telescope ($650 max) that would enable me to accurately study variable stars no fainter than a magnitude of 10. As of now, two products I have had my eye on are the 10x50 Resolux binoculars from Orion, as well as an 8'' or 10'' dobsonian reflector from Orion. As of the moment, I am leaning more towards the binoculars, despite the disadvantage of having to hunt down a solid mount that would keep them sturdy as well alleviate over-extending my neck for particularly high altitude stars. Does anyone have any suggestions in agreement or opposition of the direction I am currently heading? Would a medium-sized refractor be more suitable for a beginner opposed to a reflector?


BTB's picture
Binocular/telescope choice

You will certainly get the most light gathering power for your money if you go the Dobsonian route. I own an Orion 10" and use it for variables down to about magnitude 14.0. One disadvantage: I think the Dobsonian altazimuth mount sometimes makes it difficult to realize exactly how the field is oriented and to match what you see in the eyepiece with what you see on a chart. Since I have been observing for a long time, that doesn't bother me too much, but if I were a beginner, I would find it confusing.

For fairly bright variables (down to about 10th magnitude), I use (and love) my Orion 120mm shorttube refractor on an equitorial mount. It provides a really nice low power wide field of view, and the equitorial mount makes it easy to determine N, S, E, and W. The total cost is $600 (about the same as the 10" Dobsonian).


Telescope Vs. Binocular

I use a 4.5” Orion short F.L.  “Star Blast” most often. I pair it up with a high quality 68 AFOV eyepiece to get a nice wide field. It is a very inexpensive scope and the optics seem to be very good. I easily get to mag 10 from light polluted suburban skies. Often to about mag 10.5. The original mount was not great and I now use a much better one, but the original one was O.K. for visual at low power. I also have a 12” dob but usually use the smaller scope because of the ease of set up and transport.

For binoculars I bought a reasonable 10X50 at a local sporting goods store. It cost about $120. They work very well. I have a chaise lounge and small table for charts. It makes for a nice night in the back yard.

Herr_Alien's picture
How about telescope AND binoculars?

Depending on the magnitude range you want to cover, you might end up with bonoculars AND telescope.

You'll need an instrument that can go aabout one magnitude deeper than the faintest star you want to observe, so that puts an upper limit to mag 11 in your case. However, I found that stars brighter than mag 7-8 are difficult to observe with the same instrument: comparison stars will be quite far away, so an instrument of an even wider angle is better than the 4.5 inch (or larger) scope. That's where binoculars come in.

There's a similar topic here:



pox's picture
The best answer IMHO is a

The best answer IMHO is a decent-sized Dobsonian with a sensible finder. A lot of commercial scopes have finders that are basically geared to finding planets. To find the field of a variable you may need more light-gathering power, which means at least a 7 x 50 finder. That will further enable you to observe stars to (depending on your local sky conditions) 8th-9th mag. I used to have a 7 x 50 finder with which I followed stars to below magnitude 10 under good sky conditions. Limiting mag with the main scope (36cm) was mag 16 and just below. Your local sky makes a lot of difference!

Telescope vs. binocular

Since your original question was nearly four years ago, I assume you have long since made your decision - perhaps more than once!  But, at least for someone out there, my thoughts might still be useful:  Over time, I have reluctantly proven the wry insight shared with me by an experienced mentor during my early days of astronomy, that "one instrument will never ultimately be enough."  If you start with one, either one, you may find yourself later wanting to add the other (or at least something different).  However, even when I was observing under pristine Wyoming skies, I was never quite able to reach 10th magnitude with 12x60 binoculars, so I don't think any 10x50 binoculars will meet your goal.  I have an Orion 8" dob and value it as the best overall investment I ever made in general astronomy (after owning and selling an Astro-Physics apochromatic and several other telescopes), yet for variable stars I nearly always use binoculars for many reasons.  (For one oft-overlooked consideration, see the thread on "upper brightness limit" that Herr_Alien noted, which I find to be relevant...a 10" dob may hinder reliable estimates of a 5th magnitude variable star, for instance.)  So, overall, I guess I would agree with Herr_Alien.

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