Another newbie seeking telescope advice

[deadsimple (Ash)]

Hi all!

(Apologies for the long post)

I've been lurking on these forums for a few days and figured I'd sign up and say hi. I used to be interested in astronomy when I was young but didn't really have good equipment to maintain my interest - my telescope is a 2 inch Soviet-era refractor (see pic below) that's older than me, mounted ghetto-style on a tripod. Jupiter is a white blurry dot, I can see a maximum of 3 of its moons, our moon is a chromatic and aberrationary mess and the eyepiece falls off! I'd like to get a better set-up

My initial goal is to be able to just explore the sky (mainly the planets - Jupiter first, also DSOs) and learn, but I definitely wish to follow it up with some astrophotography as I have a bit of a background and interest in image and signal processing. I basically want a good upgrade path without having to replace or sell any equipment early on. After reading dozens of pages of threads on this forum for advice, and a rough starting $500-800 budget, here is my plan:

1) First get an 8 or 10" Dobsonian
2) Get a ToUcam

Tinker, learn the skies and astronomy concepts, take basic webcam shots for a few months/year. If my interest in astronomy holds:

3) Invest in an EQ5 or EQ6 mount
4) Grab a DMK21AU04.AS and do some real astrophotography

Is this a reasonable and safe approach? Any better suggestions? Plus mounting a Dob is just a case of removing the OTA, getting a tube ring and necessary counter-weights and all ready to place on an EQ mount?

I'm trying to decide between an 8 and 10" Dobsonian. From my understanding: those size OTAs at say Bintel are *roughly* the same length but vary mainly in weight and diameter, right? So in terms of fitting in the backseat of my Corolla, they should be the same. I also read somewhere (link) that the GSO 10" ones actually have a 12" tube with unused space, is this true? That would be a bummer as it'll make the Bintel 10" unit unnecessarily chunky.

On top of that there seems to be the massive long-term (i.e. when I eventually put it on an EQ mount) price difference between getting an 8 or 10" scope. With the 8", not only is it cheaper and smaller, but from what I understand a $500-ish EQ5 mount will suffice. The 10" requires a much more expensive mount, e.g. EQ6 (roughly $1000 more expensive than the EQ5!) to accommodate it. Would all of this be worth it for an extra 2" of aperture? I guess the main thing I'm worried about is always thinking "what if I bought the bigger scope" if I go the smaller option, which I imagine is a common issue. Then again an EQ6 mount would be very future-proof.

Final question, is it usual for the retailers to frequently add and remove products? Bintel just removed their 6 and 10" Dobsonians from the website on Friday, which makes things more difficult. The other retailers don't really seem to have anything affordable in the 10" size.

Anyway, any thoughts would be welcome. I wish there were some events in Brisbane that I could attend and chat with some more experienced astronomers but nothing seems to be listed :/

Oh and here is my current telescope:

[rmcpb (Rob)]

For what you want the 8" and eventually at least an HEQ5 would be a good set up. If you are into astrophotography and eventually go down that path don't "save " money by buying a under mounting your scope.

[Blue Skies (Jacquie)]

Yes, what Rob said - don't skimp on the mount if astrophotography is what you want to do. A light mount struggling with too much weight on it is an ugly frustation. An 8" can do heaps of stuff and will certainly help you get started without breaking the bank.

[deadsimple (Ash)]

Thanks for the replies.

I agree that logically the 8" is the safer choice. But if a sturdier mount (HEQ5) is recommended for that sized reflector, then I guess that closes the price gap a bit and makes the 10" more appealing than before.

On top of that I spent most of last night browsing through dozens of the "Solar System" sub-forum threads, looking to see what's possible with both sized reflectors. I know the photography results vary depending on the seeing, type of camera, stacking/post-processing quality, but on average I was quite impressed with what the 10" reflector can achieve over the 8".

That makes me lean towards the bigger scope, as I'd likely be itching for more resolution if I bought the smaller one. I mean, the initial price difference is only about $170 between the two sizes, and I doubt I could afford anything bigger than the 10" anyway - making further aperture fever impossible to succumb to

Anyway it looks like I'm typing a lot - if it seems like the fever has already caught on, feel free to say so!

[wavelandscott (Scott)]

The best scope is the one that you will use the most...

8 inch is a nice sized scope that will do a lot of things well.

Yes, larger aperture will capture more light but as has been pointed out will require a bigger mount...especially if astrophotography is something that you think you will want to venture in to eventually.

Like all things in life there are trade-offs and compromises that we all must make and there is no single "best" outfit that is the end all be all...get out and see some other people's gear before you buy if at all possible...

Good Luck!

[rmcpb (Rob)]

If you go down the 10" path I would be looking at an EQ6 to mount it.

[deadsimple (Ash)]

Looks like a bigger price gap now:

$400-450 for an 8", $800 for a 10".

They really don't make this stuff easy do they?

If only I could observe through one of them myself sometime in the next couple of days, to decide :/

[jjjnettie (Jeanette)]

Originally Posted by deadsimple

Anyway, any thoughts would be welcome. I wish there were some events in Brisbane that I could attend and chat with some more experienced astronomers but nothing seems to be listed :/

Hi,
If you are interested, Barambah Dark Sky Camp is being held from Friday the 26th of September to Wednesday the 1st of October. It's a couple of hours drive from Brisbane, and will be a great opportunity to meet up with some local Amateurs.
All the info you need is here:-
http://www.iceinspace.com.au/forum/s...ad.php?t=34767
We'd love to see you there.

[Hagar (Doug)]

Hi Deadsimple, I would think your choise of an 8 inch Dob is the correct way to go for a couple of reasons.
1. Light enough and small enough to transport and carry. (You will use it.)
2. The 8" has enough light grasp to allow for great atrophotography of DSO Images.

When you start to talk Astrophotography probably the most important item of kit is the mount. Start saving and go for the EQ6 it is a far better mount than the 5 and will give years of service and scope for expansion for a little more expense.
In the event of making astrophotography your prime pastime you may have to change to a low profile focuser or move the primary mirror to achieve focus with a camera but this is not as daunting as it sounds.
The only other thing I will say is, if you go down the dobsonian route is to also purchase a colminating tool, be it a laser or colminating EP when you buy the scope.
Good luck and take it gently.

[deadsimple (Ash)]

Originally Posted by jjjnettie

Hi,
If you are interested, Barambah Dark Sky Camp is being held

I would have absolutely loved to go, but it looks like prior commitments (watching over sibling + house-sitting for several weeks) makes that impossible. Next time though!

Originally Posted by Hagar

Hi Deadsimple, I would think your choise of an 8 inch Dob is the correct way to go for a couple of reasons.

Well, now that everyone who has given an opinion (including the retailer) has suggested the 8", I'd be silly to ignore the advice. An 8" aperture it is then! I swear I heard my wallet make a sigh of relief

Start saving and go for the EQ6 it is a far better mount

I've been thinking about that too, but the retailer also mentioned that the EQ6 may not be enough for a 10" if I go down that path.

Anyway: so you suggest that along with the 8" Dob, I also order a collimating tool such as this (I'll leave laser for another day). Are Bob's knobs recommended? Any other accessory recommendations?

I think once this is confirmed, I'll go ahead and order.

Thanks.

[erick (Eric)]

Originally Posted by deadsimple

Anyway: so you suggest that along with the 8" Dob, I also order a collimating tool such as this (I'll leave laser for another day). Are Bob's knobs recommended? Any other accessory recommendations?

Yes to the Cheshire/sight tube tool. Wait and see what collimating screws are on the scope that you buy. The primary seem to be much better these days, but the secondary often remain screws (so risk of dropping screwdriver onto primary mirror - eeek! So you might wish to replace the secondary. May well be a standard M4 thread - so pretty easy to make your own solution. See attached. Eric

[deadsimple (Ash)]

Cheers for that (and the pic).

I'll wait for the scope to arrive and have a look.

If no one has any further suggestions, I'll order the gear tonight.

Thanks all (this forum rocks)

[garin (Garin)]

A couple of the posts queried the capacity of the EQ6 in carrying a 10" newt. I currently ahve this configuration and the EQ6 is fine (you will need 3 weights though)
One memeber of AGWA even has a 12" mounted on one but you would to get the balance spot on and I think he had to extend the counterbalance shaft.

I have attached an image of the scope on the mount.

[deadsimple (Ash)]

Originally Posted by garin

A couple of the posts queried the capacity of the EQ6 in carrying a 10" newt. I currently ahve this configuration and the EQ6 is fine (you will need 3 weights though)

Thanks for the pic, looks like a great setup. By "fine" I assume you mean stable enough for astrophotography?

I think I'll be happy with the 8" for now (I've already ordered, arriving in a couple days). If I get an EQ6 mount later for future-proofing, that'll keep the door open for selling the 8" and getting a 10" (or something else) if it's really needed for extra resolution down the track.

Funny thing is, since I ordered .. the weather forecasts have worsened:

Friday Fine
Saturday Mostly fine. Possible shower/storm
Sunday Mostly fine. Possible shower/storm
Monday Mostly fine. Possible shower/storm
Tuesday Mostly fine. Possible shower/storm
Wednesday Mostly fine. Possible shower/storm

I guess the weather is confused as to the actual delivery date, hence the "possible". Not bad considering the level of drought and water restrictions we've been seeing in Brisbane/QLD in general from lack of rain. Everyone in Brisbane should go and buy telescopes so that the dams will fill up

[deadsimple (Ash)]

Just an update. Bintel somehow managed to deliver to Brisbane overnight - not a bad effort at all. Glad I got the 8" instead of 10" .. even this size is big enough for a beginner!

I'm just having some difficulty easily taking it outside and back in (even if I decide to put wheels on it, it will only get me halfway outside). Ideally I'd like to be able to take the setup in two parts - first the mount, then the OTA - and reassemble once outside.

Unfortunately the two springs keeping the OTA on the Dobsonian mount have incredibly high tension - making it quite difficult (and somewhat dangerous on the fingers) to attach/detach frequently and quickly.

I don't suppose anyone has a simple solution for this? Get a different spring? Or use a large metal ring to bridge the existing spring with the mount more easily without having to extend the spring as far?

(Also it looks to be cloudy and/or thunderstormy for another 6 days - saw a glimpse of Venus through the finderscope and by the time I went to have my very first look through the main eyepiece - clouds!)

[Starkler (Geoff)]

Originally Posted by deadsimple

I don't suppose anyone has a simple solution for this? Get a different spring? Or use a large metal ring to bridge the existing spring with the mount more easily without having to extend the spring as far?

I used a couple of large split rings of the type used on keychains.
Be warned that the cloth straps WILL break eventually and the near certain result is gouging your knuckle on the head of the anchor bolt.

[deadsimple (Ash)]

Originally Posted by Starkler

I used a couple of large split rings of the type used on keychains.
Be warned that the cloth straps WILL break eventually and the near certain result is gouging your knuckle on the head of the anchor bolt.

Well the funny thing is that I didn't get a cloth/nylon strap as mentioned in the manual. It came with a 2cm diameter keychain-type ring as you mentioned - took me a while to figure out what to do with it (after hitting my knuckles several times)

Guess I should grab a bigger ring. Would that work fine or does the spring really need to be stretched as far as possible for the mount to hold the OTA steady?

Sorry for all the silly questions. I just want to make sure I treat the telescope well.

(clear sky! be right back )

[Jen]

Hi deadsimple

[GrahamL]

A felt or rubber backed (so as to not scratch the ota) speaker magnet or two down the primary mirror end ..and you can ditch the springs altogether..I found rolling around in a drawer somewhere is the best place for them.. they can't bust you knuckles or manage to get under the alt bearings when your trying to lower your scope into the rocker box from there

[garin (Garin)]

Great to hear you got your scope, something you might find useful.
I bought this Digital Level last week for $35.
I'm using it on my lightbridge.
The original magnets in the base are a bit weak (kept slidiing down the scope) so I replaced them with three new ones (8mm dia x 4mm high) for about $3 from a local Perth magnet supplier. I find it great for helping to put myself in the right elevation when looking for an object so then all I have to do is sweep left and right till I locate it. (Most planeterium software will give alt/az info so you know what the altitude is to the object from your location).
Works well enogh until I get around to getting an Argo Navis.

Cheers
Garin