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Size really DOES matter.

Posted by Ed Moreno   11/03/2006 12:00AM

Size really DOES matter.. In SOME things anyway…

Let me begin this by saying that this article is written with “Typical” observing factors in mind. To me, the “Typical” observer lives in a populated area with light pollution. If you live under dark, clear skies, then the remarks I am going to make regarding smaller telescopes may not “Fully” apply, however my own experience is that overall, this work scales well until the observer lives under near perfect conditions, where even a toy telescope will make you gasp.. But that is not “MOST” of us… Most of us live with some level of air and light pollution (which are actually closely related).

Here goes.
Some people say that “The telescope you use the most will be the “Best” telescope for you”. Now sadly, I often see this in conjunction with an assertion that a small telescope that is easy to get outside will be more likely to get used than a larger instrument that requires more setup time and physical demand from the user, this advice being delivered with the connotation that a new astronomer should perhaps start with a smaller telescope.

I can’t say that I ascribe to this school of thought. In fact, I personally think that it is not such good advice. I know a LOT of people that took this advice and started with small telescopes only to use it a few times, and then let it sit to gather dust. At the SAME time, I ALWAYS recommended larger telescopes to people, and even if they don’t use them MUCH, I am not aware of anyone that I recommended a larger scope to that doesn’t use it at ALL anymore. In fact, I think that the people that STARTED with larger scopes tended on average to develop a more serious interest in observing. The “Sustain” rate for the people I know that started with small telescopes has been MUCH less than 50/50 by comparison. And of the people that STARTED with larger scopes, I think more of them have become even MORE ardent about observing. Of the people that I know that don’t use their smaller telescopes, most have kept them for some odd reason (The kids will use them when THEY get big, or because it looks good in the Family room, or because they can’t sell it for what they paid for it). But some of them won’t buy a bigger telescope because they became un-inspired because they couldn’t SEE anything with the small scope that they purchased to test the black waters of the celestial ocean above. I would even go so far as to say that I personally feel that there was an almost EXACT correlation between the size of the first telescope that people purchased on my recommendation and the amount of enjoyment the individuals reported. The people that bought the biggest scopes have reported being the MOST pleased with their decision! Kind of like a Big Screen TV I guess… If you ask most people that bought one if they wished they had gone bigger, the answer is usually “Yes!”

And I think that the basic REASON for this is simple… It is my guess that the people that started with larger scopes saw interesting new things every time they used them while the people that started with smaller scopes got turned off because they quickly ran out of easy “Showcase” objects.

Let’s look at some of these questionable (in my mind anyway) arguments for small scopes a bit more closely.

As mentioned, lots of people say that a small scope that CAN be set up easily will be more likely to get used for a “Quick look”. Maybe. I have a small 80mm refractor that I keep on my covered patio. And yes, SOMETIMES, I do lift it up and carry it out onto the uncovered portion of the patio for a look around. I am pretty good at being able to locate familiar objects without charts. I can use my red-dot pointer to locate dozens of objects just because I know where they are… But the problem is, once I FIND them, they just don’t dazzle me so much. When I have the Double-cluster in the sights of my superb 80mm scope, what comes to my mind is this thought…. “Boy, I wish I were looking at these in my 140mm refractor… They just look SOOO much richer in that telescope.” And well, they do… In fact, when I set up my 80mm scope telescope next to my 140 refractor and have guests look through each, EVERYONE I have asked has said that it was MUCH more beautiful in the larger scope. Some people even have trouble believing that it is the same object in the two scopes. The larger scope just manages to show one of the sky’s most BEAUTIFUL sights with so much more impact that it “Impresses” people, while the smaller scope doesn’t QUITE hit that threshold of “Wow”. Oh, I myself think that it is still quite beautiful in the 80mm scope, but holy SMOKES is it better in the bigger scope! (As an aside, my 80mm scope is an almost perfect 80m ED refractor, and my 140mm is an achromat with less than perfect optics…But it is by comparison, a BIG achromat, and well my friends, well THAT makes all the difference).

So, I DO use my 80ED sometimes, but honestly, not so much. And it is sitting RIGHT THERE on my patio! In fact, it is probably my second LEAST used telescope, even though it is easiest to set up. Again, the reason is simple… Not much in the sky looks dazzling in it the way it does even in the 5.5 inch scope.

As for setup, yes, the next easiest scope to use is my C8 on a Go-To GEM mount. But this is my LEAST used telescope… Hmmm. Why do I use my 8” telescope less than the little telescope? You’re asking yourself: “Didn’t Ed just say that the quick-look scope that gets used the most isn’t the right scope to use, but now he is saying that he uses his quick look scope more than his 8” scope???” Well, yes… That is what I said…. So you are asking “What is the reason for this BLANTENT CONTRIDICTION???” Silly rabbit… The reason is because I own a C14. LOL. I use the C14 the most. Yes, it is the biggest, hardest telescope to set up, but the fact is I have run down hundreds and hundreds of objects in this telescope and like the bunny, it is “Still going.”

The point here is that the scope I “Use the most” is directly correlated to the fact to that it is the scope that I can see the most through! The reality is that while I DO use the small scope more “OFTEN” (Though I am not really sure this is true) than I use the large scope, in the measurement of time at the eyepiece the balance is SOOOO FREAKING FAR in favor of the BIG SCOPE that it is not even FUNNY. I would put it at 20 to 1. While I might set up the small scope and cruise around for 10 minutes, I get bored with it too fast. But when I set up the large scope, I am GLUED to the eyepiece for hours at a time!!!

So, Don’t confuse “Frequency of use” with hard-core observing time. If you are getting ready to buy your first telescope, GET a BIG telescope… Maybe you won’t be able to use it every night, but when you DO use it, it will take you to end of time, where the small telescope will only get you to the start of prime time TV…

Yeah… Ok. Now you’re thinking to yourself: “Yeah Ed, maybe I DO need a big telescope….” The next question is “HOW BIG?”

And my answer???? Get a BIG FREAKING TELESCOPE… As BIG as you can manage! In telescopes BIGGER IS BETTER! Seriously! I MEAN it…

Ok. That isn’t practical…There are other factors. Cost, storage, transportation, physical effort… Yes, all of this matters. So in fact, there is a practical limit to how big you can or should go. If the thing is so hard to set up that you CAN’T set it up by yourself, then it will NEVER get used.

Here is my most important advice… START with NO LESS than 8” in aperture. It is simply the smallest aperture that I would ever recommend to anyone as a first scope. To start much smaller is to put too tight a limit on the ultimate potential. For some reason, the sky changes at 8” in a very profound way. It is like a magic threshold. 8” scopes start to show real character in a great number of objects that are just a pale glow or granular at smaller apertures. The nice thing about an 8 inch telescope is that it is BIG ENOUGH to be exciting, but still small enough to be managed.

Here are some general factors to consider.

Price is often one of the most serious factors in decision making.… Oh BOY have I got good news for you.. For the price of an ENTRY LEVEL 80mm ED scope and a mount, you can get a huge choice of 8” reflectors. Let me kind of take you through the choices.

If you are one of the people that has to struggle to find the money for such luxury purchases, then my advice is to start with the basic Dob. 8” Dobs are cheap. You can get an Orion XT8 BRAND NEW, for THREE HUNDRED AND SIXTY DOLLARS! WHAT A FREAKING DEAL!!!!!!!!!!!!!!!!!!!!!!!!!!!!! If you are looking to buy your first scope, and budget is your biggest issue, let me make it simple for you…. BUY THIS TELESCOPE!

Now, for the rest of you that aren’t struggling to fund the purchase, there are far more choices, but mostly, they are the same…

To the question of whether you should start with something bigger than an 8” dob, my answer is YES. Up to about 12 inches, I say “ALL SYSTEMS GO!” A 12 inch Dob can be set up to be deployed in minutes. If you have a garage, you can put wheelbarrow handles on it, and roll it out and be observing in your yard in 3 minutes. It will take up less space than that box of crap that is sitting on your garage floor in the corner. Sell that box of junk on Ebay, and park a 12” scope where that box was. Seriously, I realize that not everyone has a garage or ground floor and perhaps you are in a situation where getting a scope larger than 8 inches outside would be a challenge. But if you CAN store it in a garage or in some protected area, GET A BIG TELESCOPE! A big Dob can be outfitted with wheel-barrow handles, and wheeled in and out by a 12 year old… I PROMISE that you can find a space for a 12 inch Dob in your garage.

If you do decide to go BIG (Common… Doesn’t it feel good to think BIG!!!) as in 12 inches or even larger, you have some decisions to make.

First, will you transport it? If yes, then you probably better look at a truss design telescope. Discovery and Meade both make them… Pick one… Just flip a coin or something. They are more alike than different. Just do it…Pick one.

But lets talk about transporting a scope for a minute. I think that THIS is an area of questionable advice too. Many people say that if you get a smaller scope, you will be more likely to take it out to dark skies…. And here is my answer to this… Yeah.. You will HAVE to take it out to dark skies to see the same thing I see with my big scope from my back yard… And you know what? I have the biggest scope of anyone I know, and yet I take mine out to the local dark sky site more than any of my telescope owning friends with small “Grab and Go” scopes do!!! WHATs THAT about!!! But the truth is, I don’t do it all that much because I don’t HAVE TO! Schlepping a bunch of stuff into the back of the car or the van is a royal pain in the rear. In the time you can pack your car, I can have my C14 completely set up and aligned. By the time you get to your observing location, I will have observed 20 NGC objects. By the time you are finished packing for the return home, I AM IN BED!

So ask yourself.. Will you really, REALLY be transporting this telescope regularly? My bet is that for MOST of you, you will use it FAR more in your backyard than you will at your dark sky observing site. And YES, one of the reasons that I don’t take my big scope out to dark skies more is because it IS big, and it IS a lot to manage, but then there is also the one-half hour to one hour drive out, and the one-half to one hour drive home. And the gas.. And just finding the TIME. Trust me, if you are like me and the thousand other people I know, you might SAY that you are going to take your telescope out to dark skies a lot, but you probably won’t. And you don’t HAVE to if you can get really decent observing in your back yard! But start with a puny scope, and you will probably be FORCED to drive out to dark skies for anything but “Showcase” viewing. And as long as the setup of my big scope takes (less than 10 minutes actually), I will be observing before you can get onto the freeway…Think about it…. To be fair, even a small scope can offer stunning views in really dark skies, but a BIG scope… Well, in those conditions, the view through a BIG scope can knock you’re your astro-socks off…

But if you WILL take it out there, then the big 10 inch and 12 inch Dobs with solid tubes have definite transportation issues. They are bulky to manage, and they take a big volume of space. Minivan or SUV time. For those of you without big box vehicles, go with a truss dob. But for a telescope that won’t travel (and that doesn’t NEED to travel to do deep sky work), I actually recommend the solid tube design. It is easy to keep sealed up and always ready to go for home use. I like the Orion XT12 Intelliscope. If you really consider your situation and decide that you maybe WON’T be taking it out on the road, this is really an excellent way to go. Also, I DO like digital setting circles, and the XT 12 Intelliscope is the cheapest way I know to get into the larger aperture computer guided telescope world.

Ok, apartment dwellers? You are going to be stuck with a Truss scope OR maybe something like an SCT on a GEM mount. Either of these can be broken down and hustled outside, and can be stored in very small places. A Celestron 9.25 on an AS-GT mount can be hustled down a flight of stairs and set up in less time than a trust-tube Dob can be assembled and collimated. Now I personally am a total SCT Bigot and I LIKE having a Go-to mount, but I realize that for many, the money thing is an issue.

Now that the SCT has come into the picture, well the reason you would consider these is because of the high power tracking and maybe even Go-To, and also because you CAN transport them to a dark sky in larger apertures in a small car. My C14 with the mount will fit in a small car. Also, I find that it is just as quick to set up and have going as a 14 inch Truss Dob with digital setting circles… And I get full tracking and go-to. At a price, to be sure, but hey, I have my needs…

On this point, going over 12 inches starts to present problems of shear manageability. Ladders or hoof-time (Standing on them, that is) and other stuff sometimes come into play. In fact, I would suggest that the 12 inch be the top end for a “First” scope. Beyond this, and your commitment had better be more serious. Buy a 10 or 12 inch, and you are more likely to be satisfied with the balance between manageability and light gathering.

WHY am I so adamant that even your FIRST scope should be a large telescope?

M 13… I see STARS… Oh, so MANY stars…

M27 … I see feathers on that duck

M 57 … Man, you could drive a car through that hole.

M42… OH…. MY…. GOD!…..

And there are HUNDREDS of objects that you can reel in with a 12 inch scope that are not even dim smudges in a 4” refractor.

Maybe in another article, I will go more fully into the pros-and cons of the different choices, but for now, let me close with this summary. A first telescope purchase IS a hard decision. Sadly, I think that all of the small telescopes being sold today tempt buyers to start with a telescope that my own informal survey suggests will simply disappoint them. SOME might be OK with them, and some might LOVE them, but once you look through a BIG scope, it becomes harder to accept these smaller scopes as anything other than “Second” scopes. My advice is ESTABLISH yourself with a BIG telescope first. Get as BIG as you can afford and practically store, transport (if you REALLY are going to transport it) and manage into and out of storage on your own. If you don’t use it every night, take comfort that when you DO use it, it will DAZZLE you, and take you to hundreds of places that a small scope can’t take you.

So, there you have it… My advice is WAY opposite of what many other people would tell you, but my conviction is EXTREME. Starting with a small telescope may not be a total waste of time, but my bet is that if you take the plunge and get the biggest telescope you can manage (up to about 12 inches) you are FAR more likely to sit at the eyepiece and say “WOW” every time you take it out. And in the end, isn’t that what you WANT a telescope for?

Think BIG. If it doesn’t thrill you, then at least you know that it wasn’t because of the size.. In that case, sell it and move on to Vintage Electronics or Collectible figurines or some other hobby… But the fact is, when you start with lots of aperture, the universe gets MUCH bigger.

Don’t be afraid. This is something that you can EASILY undo if you over-reach. After all, read the Astromart adds and see how many people are selling smaller scopes because they have “Aperture Fever.” And while it is true that you also see people downsizing, often this is because they have health issues, or have changed living situations, and INDEED, sometimes it is because they DID overreach and start to big, but I think for MOST people, starting too small has been the more likely error.

Go ahead… GO for it… A BIGGER scope is almost always a “Better” telescope because I promise you, you will be able to see much more with it.

My regards.