Telescope for general city use?

[Alasdair]

After years of skywatching with the naked eye and binoculars (Nikon 7x50), and using various astronomical apps (years ago I provided the southern Messier data for a Palm Pilot app), I'd like to graduate to a telescope. It seems odd that I've never owned one, but... well, I haven't.

And of course the more I read, the more confused I become. There's a never ending world of equipment out there, and whatever you buy, there's something better. So here's my list (in no particular order):

• under $1000
• easily portable and easy to set up
• 6" aperture
• able to resolve the rings of Saturn
• equatorial mount for occasional photography
• GoTo

I suspect that all of these are mutually contradictory, but hey, got to start somewhere!


There are beginners sites out there which warn the beginner from astrophotography ("Just don't!"), but in fact one of my professional interests is digital image processing (written two books), and it seems a pity not to take a few snapshots - even if just attaching my smartphone to the eyepiece. (My neighbour, who is an excellent amateur astronomer, took some excellent shots of the transit of Venus some years ago using precisely that technique.)


Anyway, a couple of possibilities are the cheaper instruments in the Celestron NexStar range (4SE, OzScopes, $999, but only 4" and with AltAz mount), or something like the Skywatcher BD150x750 (Bintel, $729, but not motorized).


And although I've said "city use", I occasionally get out of town and away from light pollution.



Of course I'm open to all suggestions!


Many thanks,
Alasdair

[dannat (Daniel)]

you will be much better off with the 150x750 down the trk as opposed to the 4se [you are paying a lot for the goto mount]-the 6" f5 is capable of seeing planets, dso's & taking pics if you decide to go that way

you are probably better to buy either the OTA itself -and look for an EQ mount her in the classifieds -upgrading from a standard EQ to a goto EQ is usually not worth it -the conversion kit is often ore than secondhand complete goto mount

there is 1 mount in the classifieds for 450 LXD 75 it would go with the 6" newt OTA fine, but this mount for 800 is a lot better

[Hoges (John)]

I sometimes find a Newtonian reflector a bit of a pita on an equatorial mount for general viewing as the eyepiece can end up in some weird and not so wonderful positions. I'd much rather have a dobsonian newt (cheaper too, an 8" Dob at Bintel is $550. It should be smooth, easy to point at things and easy to live with. If you go the equatorial mount direction you probably need to spend towards $1000 just to get something reasonable for photography. Personally, I"d start with the 8" Dob and a good planetarium program on either the computer or ipad and go from there. A good program will show you all the 'highlights' of night sky for any given night too.

Otherwise, perhaps a 4" refractor on the best EQ mount you can afford. Something like this... http://www.myastroshop.com.au/produc...sp?id=MAS-031D

[SkyWatch (Dean)]

If you want 6" and an EQ mount: how about the "Skywatcher Black Diamond 150 x 750P complete with EQ3 equatorial mount and dual axis motor drives with hand controller" at Andrews for $749 (see http://www.andrewscom.com.au/site-section-10.htm - go to Skywatcher and scroll down)

I agree that EQ mounts are a pain for eyepiece position at times, but you can always rotate the tube in its cradle to get the optimum position...

- Dean

PS: If you aren't fussed about an EQ mount, I see there is an 8" collapsible dob in the classies at the moment for under 1/2 of your budget.

[Willow127mm (Brad)]

Hi guys I'm in no way an expert but I would be leaning towards a refractor.
I would rather sacrifice some appature for quality views.
I know there expensive but if your going to image at some stage I think they are the better option.
They need very little maintenance and are very manageable.
A thousand dollars should get you a fairly decent mount and a OK frac maybe think about spending a wee bit more and get a EQ5 and an ed 80 $1200 odd should get you very close.
you might be lucky and get it all for a thousand.
Hope this helps although I fee I have only confused you more.
anyway good luck mate I know how it feels.
Brad

[torana68 (Roger)]

Under 1K and goto, don't forget your paying for electronics instead of quality glass. You can find anything you want in the sky with your inbuilt pushto calculator (brain). Quality glass, mirrors or those other things, should be at the top of the list with a sturdy mount second, you can update the mount later.
6" on a dob mount would be ok but an 8" much better, the 8" will have better resale.

equatorial mounts that are good are above your total budget (meaning quality, repairable with available spare parts that can hold a reasonable weight). Second hand might be the way to go. If you borrow one with a Newt on it to try and have issues with the eyepiece ending up at odd angles , rotate the OTA to a better position.

[Renato1 (Renato)]

Last year I compared my 6" Mak to my 8" C8 looking at deep sky objects in my light polluted skies. For clusters and nebula (with a nebula filter) the views in both were good. But for galaxies the 6" was hopeless, whereas I could spot the smudges of the brighter ones in my C8 (though the view wasn't anywhere near as good as at a dark site).

So if you do go for a 6" or less, remember that observing galaxies is something you probably won't be able to do from your backyard.
Regards,
Renato

[Alasdair]

Thanks, folks - you've given me lots of excellent advice. I have in fact thought about the Skywatcher BD 150x750 - and I think going for excellent optics first, electronics a distant second, is very wise. And of course portability!

[Camelopardalis (Dunk)]

Sorry to disappoint but you're not going to get excellent optics for $1000 as you're into photography you'll appreciate that quality optics comes at a price.

You could get decent quality but you're really on the cusp of getting more interesting options once you go over $1000 (as a general rule), like triplet apo refractors. Visually a 8" Dob should be in reach, but it's not particularly compatible with imaging. Usually the requirements that make for a good visual telescope are at odds with those that make a good imaging scope, but not always.

IMO as you're into photography anyhow I'd focus on getting a decent equatorial mount first, like a HEQ5 for example, as you can readily mount your camera and any telephoto lenses you already have onto the mount. Then when funds allow you can get something with more focal length. Don't forget to check out the classifieds.

It also depends on your interests, as astronomical objects come in all shapes and sizes and no single telescope frames them all well.

[raymo]

Dunk is bang on the money; if you're into imaging, THE MOST important
thing is a decent mount. It doesn't matter how good your optics are, if the mount is not up to scratch, you will not get quality images. As Dunk
said, get some experience behind you, and when you decide what sort of objects you want to photograph, get the appropriate scope for that task.
raymo

[Alasdair]

Thanks again: so basically I should get a good "seeing" scope to start with (a dob?), and when money allows, move up to a eq mount?

In which case, should I get a decent ota on a dob and then replace the dob with an eq down the track, or simply buy an entirely new setup? This is already looking expensive... but I take your point that a "seeing" scope and an imaging scope are generally different, and in my beginners price range there would not be one which does both.

And I really do want something portable: the easier to carry around and setup the more use I'll have of it. Our house is already too full for a set-up telescope a stand around; it will have to live in a box when not in use.

[Camelopardalis (Dunk)]

Alasdair, it's not just a factor of budget, there are just few that sit in that intersection regardless. Probably those that would do both well would be a large apo refractor, but they're serious money by any metric! Not to mention the size and weight, and the mount required to carry them.

I guess what I'm trying to get across is not to be discouraged by budget. You can see amazing wonders and take surprisingly decent images - and most importantly, have a lot of fun - with much more humble equipment. Most of us fit into this category

To date I've done most of my beginners imaging with a 71mm doublet refractor that I originally bought for chucking in the backpack with the laptop when travelling, and I used it in a camera tripod for visual' Does it have limitations? Sure. Have those mattered to me? Not so much For extra kicks, I do still occasionally use it for visual, and it gives a mega wide field of view, enough to swallow Magellanic clouds!

So yeah, pick the direction you feel most passionate about to get started and you can always add more later. For visual, a 8" f/6 Dob is hard to beat for combination of price, performance, what you'll see and practicality. A 10" scope is substantially bigger. If you get some free time in the city drop in to Bintel and have a look, the difference is all the more apparent in the metal. With your budget you'd be able to pick up a scope and some essential accessories, like collimating tool and a maybe another eyepiece or two.

Also, when you've looked at objects from a city location, take your scope out for an evening out in the country (where safe to do so) and you'll feel like you've got a bigger scope for the cost of the fuel

[Alasdair]

Just one more thing about photography: because of my digital imaging expertise (such as it is!, ahem) I'm quite happy to do a fair chunk of post-processing. And I know that many optical aberrations, and noise, can be ameliorated this way. So although quality optics may well be the most important (and a mount), I'm prepared to sacrifice excellence for cost. So: still looking for under $1000, portable, and good enough to be able to see the Cassini division (if possible) under good atmospheric conditions. And I do get out of the city occasionally.

Still confused. I'll pop into Bintel sometime soon - I was actually there about 18 months ago looking (then) for a jeweller's loupe. (Checking the internals of a second-hand watch.)

Thanks again, folks!

[Camelopardalis (Dunk)]

Post-processing, to a greater or lesser extent, isn't really optional with deep space imaging, it's a necessity. Long exposure astrophotography introduces thermal noise with uncooled cameras such as DSLRs and a common technique to deal with that is by stacking many sub exposures before further post-processing to bring out fine and faint detail and colours. But processing will only get you so far...you need good data in the first place or else garbage in, garbage out!

But....planetary imaging and deep space imaging are quite different and have different requirements. With planetary imaging, gone is the absolutely necessity for an equatorial mount, as field rotation is negligible at the frame rates desirable to capture the subject in often fluctuating seeing conditions. So fast frame rates are better here, for example 30-60 fps or even higher.

Visually, the Cassini division isn't a major challenge for a smallish telescope, it all depends on how good the seeing is (seeing is the stability of the atmospheric layers that affect the ability to see details, or just a blur). Typically, we can effectively observe planets from the city and with the Moon in the sky (although cities can introduce localised negative effects such as buildings radiating heat that can spoil the party). This is the opposite of hunting for faint fuzzies, when we want a dark site with a Moon-less and transparent sky. Transparency comes from drier air in the atmosphere, giving rise to greater clarity and contrast. It's often said that seeing and transparency are exclusive with a good night having one or the other, rarely both.

[Alasdair]

Well, I popped into BinTel (Melbourne) this morning, and as people here have said, the staff are very knowledgeable and helpful. They recommended - as a beginner scope - a 6" dob (about $350 I think it was); very straightforward, superb value for money, easily transportable. Basically you just bung it down and away you go. Then there's an 8" dob for about $200 more, which is not much less transportable. And as the bloke said, if my budget is $1000, I can spend the rest on some nice eyepieces or filters. (And on their $90 laser collimating tool.)

That's advice I've seen all over the Internet - everybody's advice for the starting backyard astronomer is a dob.

However, I was very taken with a 6" SkyWatcher reflector on an eq3 mount ($729); an 8" reflector on an eq5 mount is about $995. And I do like the idea of an equatorial mount for the occasional photograph.

Portability is a must. Any scope will probably sit in our backyard shed when not in use, either boxed or setup; then it will be dragged about for viewing. Probably into our street, where even with the street light it's possible to get some good viewing (as I've seen through my neighbour's 8" motorized and expensive SCT.) And occasionally down to the coast, away from city lights.

What I really need to do is have a look through other people's scopes to get an idea of what they are actually like. Where's a good place to do that?

Choices... choices...