If I tell you what I have......

[Ant]

Sod!

BTW, I'm going to make sure that you have the pitch next to me at Kelling next Autumn!

[Whippy]

Didn't you hear mine at Kelling Steve? Almost everywhere I looked mentioned that the PE on it was pretty bad. But it can be autoguided so that may counteract some of it's deficiencies. On top of that I wouldn't fancy having an 8" tube plus imaging gear plus another albeit small scope. You'd be pushing your luck with that lot. I reckon you might be able to autoguide with a 6" OTA plus a 66/80mm job though. But for viusal it's great, easy alignment and it's pretty darn reliable, for the money it's a great mount when you take into account what it can take weight-wise and full GOTO.

You know I sold mine recently to fund my EQ6 purchase yes? The bloke I sold it to told me after he received it that he reckoned it was made on a Friday afternoon because it had so much play and slop in it, so he did the traditional strip down and re-grease job on it. I thought it was OK myself...

Tony..

[MartinB]

Martin, what's he going to put at the ED80 end, though, to capture photons?

Well I assumed he was going to use his brand new Canon EOS 400.

[themos]

of course, excuse my stupidity.

[Tim]

I have read some of the manual now for the nexstar, and it does say in there that for decent long exposures you would need to autoguide it, although it describes the autoguiding being done manually through the alignment scope, which apparently has a red dot to centre on a star and you manually tweak it throughout the exposure. You can also link it to a laptop/camera I think, but this is not a route I want to take. Has anybody tried that manual method?

As I dont want to piggyback another scope and camera, that mount should be man enough, but if it really isnt good enough for long exposures then would I be better just getting an ALT/AZ mount and have an easier setup time? I dont feel inclined that way......

Is there a GOTO mount that will do the job more accurately than the Celestron one then? Does it have all the funky 'beginner' features? Somebody mentioned the HEQ5 or something, and a scope that can do imaging and visual at once, any other endorsements? Who makes those bits, is there a website? I reckon that the NS8 SGT is a reasonable compromise??

[MartinB]

Have a look at this thread TJ. Although aimed at people on a strict budget it could also apply to people wanting to get into imaging http://stargazerslounge.com/index.php/topic,12089.msg125533.html#msg125533

For visual you want aperture, the more the better. Goto is a moot point. Some people enjoy tracking down targets - and some of the best targets really aren't that hard to find. Once you get the hang of it it can be much quicker than goto.

Imaging is completely different. Aperture just isn't the issue in the same way. What matters is focal ratio. The exposure time you need is determined by focal ratio. so an f10 20" scope will require a longer exposure than a 3" F5 scope. In fact it will require 4 times the exposure to get the same signal to noise ratio. So for starters, esp unguided you want to get the focal ratio down.

The next crucial thing to consider is focal length. The greater the magnification the more every little shake and inaccuracy of tracking is shown up. Therefore lower focal length scopes are much more manageale than longer ones esp unguided.

Therefore, for unguided and when starting out you are much better with a short focal length.

So that gives us - short focal length, low F ratio

Next up is field of view and camera chip. Field of view is directly related to the focal length - the longer the f/l the smaller the field of view. Long focal length is good for some targets e.g. M57 and bad for others e.g. M31. The other thing that determines the field of view is chip size. A DSLR has a BIG chip. This gives you a nice big FOV which gives you the potential for using longer focal lengths - but bearing in mind the porblems mentioned above.

Finally there are 2 other optical considerations, especially with a DSLR, which are the diameter of field illumination and field flatness. Telescopes vary in how big a chip they can illuminate and also how flat the field is. The end result with large chips such as DSLRs is vignetting and distorted stars at the edge. This needn't be a major problem with cropping and can also be improved as imaging techniques develop. However the problem gets worse with use of focal reducers to bring down the focal length.

IMHO and 8" SCT with a native focal length of 2000 and F10 would be a major challenge on a world class multithousand pound mount unguided. OK you'll get images of bright DSOs such as M42 and M13 and you might be pleased but you are more likely to feel a little frustrated. You can pull down the focal length with a reducer to F6.3-7 which will be an improvement but you are then on the limit of how far you can go with a DSLR. C8's are fantastic scopes with smaller chips such as the Atik 16 - you can use a Meade 3.3 reducer to give you a very manageable focal length, short exposure times and good field illumination.

With a DSLR I think you are better off working at the native focal length of the scope. This was why I suggested an ED80 at F7.5 and a focal length of 600. Better still maybe, but more expensive would be a megrez 90.

One final, point about using a small scope - they put less strain on the mount and less windage as well - tracking will be better and you have spare capacity if you do want to start guiding.

Only from what I've read, and not personal experience, an HEQ5 is a significantly better mount than the Celestron offering.

So, it comes down to personal choice but these are what I think are the essential principles to understand.

[Whippy]

Of course you could always buy a HEQ5 and an ED80 as per Martin's suggestion and always buy a larger OTA or a solid tube dobsonian for some visual fun and games....

Tony..

[MartinB]

Of course you could always buy a HEQ5 and an ED80 as per Martin's suggestion and always buy a larger OTA or a solid tube dobsonian for some visual fun and games....

My thinking exactly

[Ant]

I've got the HEQ5, ED80 and a 300D and have got some fairly good results from setting up and leaving it imaging while I do something else. You cannot get away from the processing time though!

I do plan to get another scope (maybe a ST80) and the PRO upgrade at some point so auto guiding becomes an option.

But if you want longer exposures... what about a Vixen Super Polaris Mount. The ED80 and 400D combo would track for a while I think.

Ant

[Tim]

Damn its hard to be recklessly impulsive in here! Instead of all this wonderfully helpful advice i'm more used to some 12 year old 'expert' going

"yeah dude what you want is like this l33t exocet system, it like totally rocks (roxorz), man you should totally get that."

And I go, "Gee, thats great, thank you for your opinion, and only £15000. I cant believe they threw the blue 'Pimp my scope' streetwise light strips in for free. Credit Card ok?"

No, I can see that for once I just may be dealing with people who actually know what they are talking about. Too bad Steve at First Light Optics (not picking on you, dont know anybody else's name yet), you should have locked the door when I turned up yesterday, all wet behind the ears, with the credit card burning a hole in my hot pants.

But that was then, this is now, and.......I'm INFORMED!! Well at least thanks to Martin, Ant, Steve and a cast of tens, I am in the curious position of having a little knowledge, which we all know is a dangerous thing. At least, I now appreciate a fraction more of the complexity of my original question.

Im now assuming, contrary to my prior assumptions then, that NONE of the mounts ( at realistic prices) are capable of providing guidance that will permit decent long exposure imaging. Im assuming that they will all deviate to some degree or other and that the only way to keep them perfectly on track is to control them with another scope and camera. (I guess that's what auto guiding means?)

I also take it from the comments that if, heaven forbid, I do ever want to mount a piggyback scope and gubbins onto the OTA I eventually re-decide to buy, then one of those HEQ5 jobbies is a better bet than the celestron offering.

From Martins comments, I also take it that taking a few holiday snaps of distant galaxies will be of better quality WITHOUT auto-guiding IF (sorry, not shouting, just emphasising) the focal length of the OTA is shorter, because that will allow shorter exposures.

But as I'm likely to spend most of the time peering down the thing instead of imaging, (because I dont have the time, auto-guiding, or intelligence to do it), then Im better off with the biggest aperture I can afford. Which brings me back to that Celestron. Here's a question I dont understand. Is the ED80 mentioned standing outside the sweetshop window looking in at the celestrons, thinking "Boy, I wish I had an aperture like that", or is it there on the shelves WITH the celestrons and pontefract cakes, or is the celestron outside in the cold, cursing the fact that he was back of the queue when God handed out apertures??

And is bolting an 8" celestron SCT to a HEQ5 (or even EQ6 PRO Synscan) the same as bolting a ford mondeo shell to a ferrari chassis?

And what is the difference between the HEQ5 and the EQ6? The EQ6 looks very substantial, I think they use them for spinning the RADAR dish at the airport here.

And if the Celestrin mount REALLY sounds like a coffee grinder, will that make me thirsty, the same way that splashing water makes you....well, you know? Seriously, noise at home wont be an issue, I live next door to an airport, I cant imagine the pilots of 737's phoning in and saying "For Pete's sake stop revving up that scope, its keeping us awake", BUT, and its a big butt, (like the missus'), If I do combine my two hobbies then noise could be an issue. I sometimes do a bit of, erm, nature shooting spotting. This gives me access to large areas of rural land in the early hours, which could be ideal to combine with a bit of astrogawping. However, a coffee grinder could well scare away the intended GBO's (Ground Based Objects) with the result that the farmer will go hungry and when he dies of starvation the council will build houses on his land, and streetlights, and the rabbits, (who care little for the needs of astronomers if what I hear is true) will be laughing all the way to their warren, whoever Warren is. At any rate, quieter will be better I think.

Ant, if you haven't slit your wrists in despair yet, then I'd REALLY like to see the images you describe as 'fairly good' if there's any chance? (C'mon, dont be shy, im still impressed by digital watches)

And one final question, for this post, (keyboard is wearing away), If I did go with Whiplash's suggestion and buy the HEQ5 (with goto etc) and ED80 AND another OTA, then I could slap them all on the same mount and what one was seeing, the other will be seeing I guess? So I could be saying to the kids "Hey guys, come and look at this blumming great cloud" through one scope, whilst taking its portrait with the other (aperture challenged, focal length restricted) OTA.

One more request for personal information, how long did all of you pursue the hobby avidly till you moved on to something else? Be honest. Maybe I could combine astronomy in some way with my other great passions in life, so as to prolong the honeymoon period. Any suggestions?

Thank you thank you thank you again for all the great advice and help, it is really appreciated. Sorry if I go on a bit, am ever so slightly excited about all this. Besides,if we only get to cross lifes ocean the once, let's make some waves eh?

Are there any decent astro shops near me (Coventry), well stocked/knowledgable etc blah? Wouldn't mind having a quick butchers at some kit.

Cheers

TJ

[Whippy]

Thing is mate, stargazing is one of those hobbies where by and large, you get what you pay for.

Here's a soundbite review on the three mounts you're looking at.

CG5GT: Cheap but definately cheerful. Noisy, not great for imaging but if all you want it for is visual observing, then for the price it's t'riffic.

HEQ5: It's a much better made CG5 basically. Takes a little bit more weight than a CG5 but it's quieter, more solid and better for imaging.

EQ6: Bigger and if you need a heftier mount than this, you're looking at an observatory. This is a mount for life, not just for christmas.

If I was in your position, I'd go for the bigger visual OTA on an HEQ5/EQ6 now and get used to sticking your eye into an eyepiece before taking on an even steeper learning curve by taking on the imaging side at the same time. By your own admission, time is a luxury you don't have in spades so my thoughts would be to get some gear, get used to it and enjoy then think about picking up an ED80 or something similar to connect your DSLR to.

I think what I'm getting at is the old cliche "Don't try and run before you can walk". You'll have enough fun trying to work out what goes where, polar alignment, the GOTO setup, what eyepieces work best on what objects etc etc so IMO you can get all the basics down, then spend another couple of hundred quid and your imaging adventure is yours to embark on.

Tony..

[Tim]

Right! Brilliant! That's what i wanted to hear I think.

Unless there's any loud dissenting voices I reckon its gonna be a HEQ5 mount with GOTO, a Nexstar 8" OTA, (possibly 9.25") and the rest of the bits n bobs. Just gotta shop around for the best deal now.

Thanks a million guys. And girls. Wait, are there any girls here? I just had flash of inspiration about combining my great passions in life.........................

TJ

[barkis]

TJ, In view of your lack of experience, and your obvious enthusiasm is well noted, however the advice Tony has laid out for you would get a lot of votes. If you attempt too much too soon, you run the risk of complete demoralisation, and kick the whole Idea into touch. By doing that, you will deprive your kids of at least a chance to learn a whole lot about the night sky, and who knows, one of them might progress to the imaging stage. Then if that is the case, you have a teacher on site for yourself. Kids and computers gel better than adults and computers.

Ron.

[themos]

TJ, there really is no hurry to get into imaging, that stuff up there is not going away soon. My first (and current) bit of imaging kit cost under £100 (including mount, scope, camera) and ok, it's pretty useless but it's helped me learn a little bit. I am in no great hurry to move up because I notice that the internet is full of amateur websites that last two years. I guess there's a lot of burn-outs after that time. To be honest, I hear you and think "he'll be selling his kit in the summer". So, my advice (which you are welcome to completely ignore since it's free) is take your time and get something simple that will show you the sights. That's what Dobsonians are for, like my Skyliner. Oh, and another point: you live near an airport, the planes will ruin your long exposures quite often, won't they?

[Tim]

Yup. Just to stress the point, I AM gonna go with what Tony suggested. Gonna spend the clear winter night, maybe nights, just getting used to the stuff, showing the kids whats what etc. Maybe this time next year think serious about imaging.

I hear your points about starting simple etc, and am grateful for them. I like to hit the ground running, I like to suceed in whatever I do, I like it to be enjoyable for myself and those around me, and I like to buy the best that I can afford.

I would think that if a hobby lasted seriously for two years, then thats not bad going, given that its around 4 percent of our waking lives. I wouldn't want to have just one serious hobby my whole life!! Im gradually building up an inner database of things that I enjoy doing and have some success at. I want now to add stargazing/astronomy to my current list of activities which includes photography, painting, horse riding, cycling, shooting, fishing, roller/ice skating, carpentry, toy-making, writing, landscaping, gardening, garden design, caravanning, camping, walking, golf, computers/IT, fishkeeping etc. Im not saying I do all these things every week, but I can if I like, and can be confident knowing that I can hold my own in any of them. There's a slot in the early hours where most of these other activities are impractical, and I think astronomy will slide just nicely in there.

Sure there will probably be some very expensive kit sitting idle for 95% of the year. But when it comes time for that 5% to shine, I want it to need a solar filter I think i'd only regret spending out on cheap kit to start with.

(Please dont think I have money to burn, quite the opposite, I can barely sustain my chocolate habit, its just that carol singing season is coming up, and folks tend to pay me to shut the hell up.......)

Just noticed about an hour ago that old flirt la lune popping her cheeky smile through the clouds in a rather spooky fashion, so am gonna go now and check out the footage captured there.

Thanks again guys. If the wife calls, tell her im in the hot tub with a foursome of redhead college girls, please dont mention scopes or shops or anything, I could get in real trouble with her........

TJ

[barkis]

I am just disappointed you have golf in a sort of mid range in your list, indicating it might not be one of your favourite sports/walks.

Shame that, I would have you down as a low handicapper too. TJ.

A game I revel in playing, but unfortunately, not very good at sometimes.

Ron.

[GazOC]

I like golf but I've always regarded it (with no real foundation) as a game rather than a sport.

[GazOC]

TJ,

FWIW heres my "ideal" (ie slightly more expensive than you asked for ) solution. Skyscan HEQ5, Celestron 9.25" SCT, an ED80 and a few Hyperion eyepieces. It's over budget but a cracking setup.

Gaz

[Tim]

Interesting that you all seem (to me) to go for a celestron.

Is there a Celestron versus Meade debate raging anywhere?

[GazOC]

Is there a Celestron versus Meade debate raging anywhere?

Not really, its a loooooong story but Meade are in big financial trouble and the Celestron 9.25 has a great rep. with astronomers, its supposed to be due to the longer f ratio primary than all the other SCTs, some people think this is a bit of an urban myth but enough seem to rave about the scopes that there maybe something in it.

[GazOC]

...also Celestron telescopes can be mixed and matched with other mounts, with the Meade SCTs you are generally stuck with the fork mount they came with and it can be a pain to attach other scopes...something to consider if you are thinking about having more than one scope.

[Tim]

I remember SteveL now saying about them being in the financial frying pan.

I know Steve uses the met office satellite pics to guage his sessions, anybody have a link?

thx

[GazOC]

Infra red (nighttime)

http://www.metoffice.gov.uk/satpics/latest_uk_ir.html

Visual (daytime)

http://www.metoffice.gov.uk/satpics/latest_uk_vis.html

[Tim]

Great, thanks.

Just need someone to sell me some kit now.................

[Tim]

one more thing.

Carbon fibre or aluminium? or rather, what benefit dies the extra 50 quid get you in real terms? real definable differences>?

thx