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Established wisdom, or opinion parroted as fact?


russ.will

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I threw an opinion into the mix in the beginners forum the other night and decided I should expand on my reasoning here.

Even somewhere as benign as SGL, you still have to remember this IS the internet. That means opinions repeated enough by people with large post counts, gain credence as fact among the rest of the forum. It does not hurt to challenge that, if only to get people thinking, as long as you do it in a reasoned way. So.....

What got me thinking was the humble 8" Dob. For instance, I've noticed that the most recommended scope for a beginner is an 8" Dob; 10" if there's a sniff of the OP having a bit more to spend. The thing is, a rake of this recommendation appears straight off the bat, without further quizzing of the OP, but for most newbies, I think it is wrong.

True, a great many people started there and went on to bigger (some might say better) things, but a lot do not. You don't have to be Poirot to notice it's also the most sold scope on Ebay, along with the EPs it came with; reasons (excuses) of needing the space, etc, being given. The ratio of 8" Dobs for sale on Ebay is greater than on here. A lot of people don't stick with it long enough to achieve the fifty posts required for access to the classifieds. Why? Because if you don't know your way around the skies, you'll find it really hard to find stuff and you'll break your back grovelling around doing so. It is also a scope that will likely be way off the mark in collimation out of the box and be harsh on the rather basic EPs* it came with.

When I started, my Explorer 200p only showed half the primary when looking down the focuser. They really can arrive that far out of whack and dealers these days are driven by price, so they are extremely unlikely to have seen more than the outside of the box you've been shipped. Few would actually check the scope and if they did, most people would whine they're too expensive. Service costs.

So, if you do find something on your first light with your new scope and then pop in the 10mm MA it came with, it will look rubbish. De-collimate your scope with a half decent EP and have a crack at Jupiter. It's not impressive and that's as easy as it gets. For a n00b, it's confusion time.

In other words, it's not the most intuitive scope, it has a built in steep learning curve just to get it to work and requires immediate upgrades just to get near what this, admittedly capable scope in the right hands, can deliver. The 8" Dob is best suited to someone who has at least used binos, or a friend's scope. That way, they'll have advice on hand.

So my contention is that, in this push button, battery driven age, the ideal beginners scope is a 127mm AZ GOTO Mak.

I can hear the hackles rising, so let me justify this.

I'm not interested in the cries of 'It needs to be level, it needs to be pointed North!'. That involves a bubble level and the one star everybody knows. People who get the date format wrong should RTFM! Anyway, if this is tricky, how are they going to get along with a Planisphere? No, the learning curve is minimal and when the crisp little optics and it's long FL, which is easy on cheap EPs hits a target, it's going to be a sharp view. If it doesn't hit the target first time, the erstwhile n00b will slew around a bit and unless they're complete attention deficient, will hit the target.

This is my point. Getting the first few targets a newcomer sees to be clear, is the hook that keeps them engaged. Jupiter will look good in a Mak. Saturn at any size when sharp is unforgettable. The moon will look amazing and M42, M57, globs, etc, will be good enough to show people there's a universe out there they hadn't even considered. I know an 8" Dob will do these subjects better, but it's not exactly Wow! territory. There are plenty of atmospheric UK nights and particularly from suburban locations, where a 5" Mak might actually do these subjects better.

Now I know that hardly anybody reading this will still have their first scope, but if one of these had been, it would still be a great little grab 'n' go, plus a handy mount for an 80mm ED/Apo for the same purpose, plus white light solar, etc, etc. Nobody who starts in the hobby with an 8" Dob stays there. In the long run, rationally, the humble 5" Mak GOTO is a very handy little weapon on a number of levels and one that has uses further down the line.

Russell

* One of the scopes I bought at a time when my collimation learning curve had long since flattened off, came with the usual 10 & 25mm MAs. For a laugh, I thought I'd give them a go. You know what? In a 300mm F4.9 Dob, they weren't that bad. The deficiency I recalled, was in fact, mostly mine in terms of collimation - It was far easier to blame the EPs and post yet another 'What EP for a n00b' thread....

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My first decent scope (and the first I paid for) was an 8" Dob.  It arrived collimated amazingly, and I did't actually collimate it for the first 8 years of owning it!

 

Gave me spectacular views throughout that time, and with stock 10mm and 25mm EPs only :)

 

I'm fairly lucky by the sounds of things ;)

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I don't disagree with you but I don't agree eirher. The 200p is in many ways a better scope . You see more detail. its easier to use straight out of the box and its cheaper. However you are absolutely right that that doen't make it necessarily the best scope as you pointed out peoples needs are different. I don't drive and I can't view from home so my gear needs carrying this rules out the dob and by the way the 127 skymax as the mount tripod and battery makes it too heavy for my 3/4 mile walk to view. So I do agree that the dob isn't necessarily the best scope and by the same token neither is the skymax and for similar reasons neither is my ts 80x480 triplet which although double to triple the price of both scopes doesn't from a city site show as much as either the skymax or dob. All scopes are a compromise so there is no stand out best scope just a best fit. Which of course is where you came in and something I do agree with about getting as much info as posible and listening to what is being said. The best scope is a mixture of affordability, usability, portability and performance where your priorities lie depends on the order and weight you give each attribute. to my eyes the 200p out scores the mak in affordability , performance, tied on usability and is slightly less portable.

So my definition of  best scope is" the biggest scope that you can use easily and comfortably in all the places you are likely to use it" for some people that;s going to be an 18" dob in the back garden for others its going to be a 70mm achro they have portaged into the countryside,

So is the 200p the best scope? No. but it can be  and likewise for the skymax or the celestron 70 or edge 14" on cpc et al

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Thanks for this.  I've been using bins for the last couple of years to try and learn my way around the sky.  I originally planned to get an 8" dob (based on the very advice you speak of), but now I'm leaning towards a Nexstar simply because I don't want to maximize viewing time.  I like star-hopping with bins and naked eye, but don't want to do that with a scope.  

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And that's another good reason. Time is, for many people short. Dump a GOTO Mak in exactly the same spot every night and you'll be slewing from one target to the next in minutes, not using multiples of those minutes prodding around the skies.

 

For those with the time and patience, go Dob, but lets not assume that is the case for everybody. It's not.

 

Russell

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My first decent scope (and the first I paid for) was an 8" Dob.  It arrived collimated amazingly, and I did't actually collimate it for the first 8 years of owning it!

 

Gave me spectacular views throughout that time, and with stock 10mm and 25mm EPs only :)

 

I'm fairly lucky by the sounds of things ;)

As I stated above my 8" Newt was so far out as to be comical. You can't assume because even based on our sample population, statistically you'll be missing 25% of the primary mirror.

 

Russell

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Great advice on the start post and I do tend to agree about the ease of a Mak (obvs as my main scope is now a 150 Mak!). To add a bit of further balance, my first scope was a Celestron 'First Scope' a mini Dob brand new for £50. This did the trick for me as the Moon, Jupiter, Venus and Mars were all visible through it (with pretty rubbish stock eps) and made me want more. I then went to a 150 Dob and although it was good it is not as good (in my opinion) as the 150 Mak. Granted, my Mak is on a GOTO mount which makes it FANTASTICALLY easy to find stuff, but the views I have had through the Mak of the planets have been awesome and has even got me looking at DSOs - something I found not so easy with my Dob.

So, I would concur that a 127 Mak would make a great starter setup but equally you wouldn't need to spend even that amount to get the bug - a decent set of bins would also do the trick - I certainly agree that jumping straight to a 200mm Dob may not be the wisest choice for a total noob.

As loads of people will say: the best scope is the one you use the most. On that measure my 'best' scope is my ST80 as I use that even on holiday abroad and can set it up in minutes...

Edited by Dazzyt66
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