Advise on first telescope please guys

[Daemon]

Hi guys,

I’m after some advice for my first serious telescope purchase. I’ve had a cheap and nasty little 2 inch refractor for 30 years (except that 30 years ago they weren’t cheap, just nasty), but have mostly been using binoculars and naked eye for the last few decades. However, towards the end of this year, or perhaps next year, I’ll finally be able to afford the time and money to make it worth my while getting a descent amateur telescope, so I thought now would be a good time to start planning what I might want to purchase (with plenty of time to change my mind, think about it and learn what I might need to know in order to make the best purchases).

My greatest interest is in deep sky objects and their CCD imaging, but I find the whole CCD imaging thing very confusing with regards to what is needed to do it fairly well. This is not helped by the rapid improvements in imaging technologies for a given price point, meaning a lot of info on the web appears to be discussing equipment with one or two generations of development difference, alongside comments and techniques that may apply to the latest gear. And, quite frankly, I just know nothing about the subject, yet.

At the moment I’m thinking of a Meade LX200GPS 10 inch, or 12 inch, but I’m not sure. Some opinions I’ve read suggest these are a wonderful tool for the tasks I want, and others express various criticisms about mount stability, and optical quality, let alone my own confusion as to whether the highly criticized equatorial wedge is needed for CCD imaging, or should a field de-rotator be used instead, or should just the Meade (or someone else’s) optical tube assembly be purchased and put on someone else’s German equatorial mount (though either way I would like goto). Though I do require portability.

I’m even more confused about CCD cameras. Meade’s Sony chip B&W is a good price and the few reviews I’ve seen by those that have bought them are favorable, but there is little comparison reviewing except as sales aids to competing products. Sbigs seem way cool, but attract a big ouch factor in the price tag from the Australian retailers I’ve found so far (way beyond what the US exchange rate and shipping costs would suggest).

As far as other accessories go; no idea what I might want or need, and apart from obvious things like dew control, are probably going to be heavily influenced by the OTA, mount and CCD set up, but I need suggestions because there’s sure to be things I haven’t even thought of.

All up I’d like it to come in under $10,000 aus ready to run. That’s a lot of ground to cover, but I’d appreciate any opinions, thoughts and feedback. Feel free to suggest alternative brands, but I’d appreciate comments on why you think they’d be beter choices and a guestimate at price or link to an aus retailer.

Thanks in advance everybody.

[ving]

holy cow batman!! you are going big arent you!
I am just a push-to dob user so I dont really have anything relevant to sugest... so I'll just say hi and welcome to the forum :)

there are plenty here that will be able to help you so just hang in there and some1 will be along :)

[iceman]

Hi Daemon!

:welcome: to the forum! How did you hear about us?

It sounds like you've done a good amount of research already, so you're on the right track.

To me, it sounds like the 10 or 12" LX200GPS (I think these are $3000 approx for the OTA), on a GEM like the Losmandy G11 (with goto, I think is approx $5000) would suit your needs. Don't forgot you'll also need a guidescope, something like an 80mm ED (extra $600 or so). I'm guessing you have a laptop already?

As for CCD cameras, i've seen better and better results with the DSI (or DSI Pro), so they are a fairly good cheap solution. Obviously the SBig's etc are better, but at that price, it really depends how much time you think you'll have to get into imaging. It's a big investment.

Have you considered a DSLR, or are you more set on astroCCD cameras?

I'm sure some others will chip in too! Good luck!

[acropolite]

Daemon,
There are lot's of opinions on what's right and what's not, my suggestion is to search out as many links on the web as possible and examine the results. From what I've seen many people are getting good results with stock DSLR's and ToUcam's and both Alt/AZ scopes on wedges as well as Equatorial mounts. I've got an LX90 which are available now in 8, 10 and 12 inch sizes at less cost than the LX200 series; my decision was based on cost and the results I have seen from others using the same equipment. To achieve any sort of result I will have to guide the LX to correct for errors in the drive system. Bearing in mind that I have never fired an Astro shot in anger, if I had a budget of $10000, judging from the information I have seen from the learned members of this forum, I would be aiming for a good quality equatorial mount, most likely a Losmandy (for quality and price as well as ease of interfacing) and a suitable OTA (probably SCT) with a good quality refractor piggybacked for imaging. Try this site for some info on what is needed for autoguiding as well as some sample images on a meade/wedge system. http://www.users.bigpond.com/lansma/Default.htm You might also like to check out IIS member Eddie Trimatchi's site for details on his setup. http://astroshed.com

[[1ponders]]

Hi Daemon, and welcome.

I've just gone through pretty much this same process myself. I originally bought the LX200GPS 8" with a wedge for Astrophotography. Very happy with the OTA quality, though I did find the wedge very frustrating. But that's only my experience, others have used it, made modifications to it and love it. It frustrated me enough to sell the scope, buy a new 8" Meade OTA and mount it on a Losmandy GM-8. IMHO its the only way to go if you are considering a serious step into the astrophotography field. Not necessarily those particular items, but definately OTA and GEM. Plus guidescope.

If you are looking at 10 or 12" OTA then a very beafy mount like the G-11 or the Skywatcher EQ6 or the Celestron CGE. All can be GOTO driven in some form. The Losmandy with the Gemini as an extra, I'm not sure about the base configuration of the others though.

For CCD imaging, I use the Canon 300D though its main limiting factor is the IR filter attached which removes a lot of the lower red spectrum. An option if your interested in this line is the new Canon 20Da which has been modified by canon specifically for astrophotography, but with the use of filters on the lens can still be used for "normal" photography. I haven't seen much about Meades recently released B&W DSI, so no comment :) Hopefully others here who have had more experience with dedicated astrophotography CCDs will pipe up with their opinions.

To get an OTA, good GEM, guidescope, ToUcam (planetary imaging and autoguider) Autoguiding emulator, and CCD/CMOS camera you will be giving that $10,000 a serious nudge. EG Approx - Meade 8" $1600, Orion guidescope/widefield - $695, Losmandy G-8 with Gemini $4500, Canon 300D $1300, guide rings, focal reducer, associated accessries, $500-$1000, ToUcam plus adapter $200, Guiding emulatorif needed $100 (go for a starmate $200 you'll love it) and that's all just for starters. I read somewhere that if you have $XXXXX to spend on just mount and OTA, spend 2/3 on the mount and 1/3 on the OTA.

Hope that's helped a bit

[Daemon]

Iceman, I found your site entirely by accident when I was googling for Cartes du Ciel, but foolishly left the .au filter on (the phrase appears here and there). I read the descriptor and thought it interesting enough to go back to later and have a look (after I downloaded the 1.75 cartes upgrade). It might be worth noting though, that if your site ever came up in a .au google for "ameture astronomy" it was so many pages back in the list I never saw it (don't know what, but I'm told there are things that can be done to improve this sort of thing that don't include banner adds for web ****).

I haven't really looked at the DigiSLR option. I have a couple of excellent silver SLRs and a nice digi compact that covers my vanilla imaging needs, so I don't need another vanilla camera. And though I'm not sure, I feel that an SLR is not going to be comparable to an astro-CCD. I don't see how they can come close to coping with the thermal noise at long exposures (never heard of one that can be cooled and as I understand it no amount of dark field averaging will cope when it gets too extreme) and there are the filtering and sensitivity problems 1ponders has pointed out. I've never heard of the Canon 20Da though. Still, guessing around $1600 to $2000 for a DigiSLR, plus $600 to $800 for a big heavy guide scope, another couple of hundred for a Phillips toucam and adapters, puts the thing in the range of the lower model SBigs. However, from what I gather, SBigs use a double chip set up to give extremely accurate on axis autoguiding, with no sensetivity cost / light loss to the imaging chip and thus no need for a heavy guide scope or secondary guide imager. This seems like a way cool trade off, if the lower price SBigs do in fact, have the feature (of which I'm not sure). This would also apply to Meade DSI pro too, as I don't think it can guide without loss unless a secondary guider CCD is used either. Another factor may be the colour chip in digiSLRs. I've been given to understand that none of the colour chips can outperform B&W chips for sensitivity vs noise and other imaging parameters, though I'll freely admit I have no idea really, but I'd preffer a better CCD and do three colour exposure sets, than a colour ccd that wasn't quite as good. I want the limiting factor to be my skill and experience, not my equipment, at least for a couple of years.

I also have a friend who insists he can build a CCD camera that performs as well as the upper model SBigs, for a fraction of the cost (though he mentions things that don't fill me with confidance, such as cooling via wrapping the thing in an ice filled tea-towel ugh like your fingures aren't cold enough on winter nights. Not sure melting ice really counts as precision thermal control).

It's also been suggested to me, that light sensetivity of a good astro-CCD is so much better than eye or silver cameras, that it gives equivalence to an aperture of 4 or 5 times the working aperture conservatively, if the scope is of good quality and the CCD used well. THe person who has been trying to convince me of this suggests that if money comes to the crunch, downsize the scope aperture to an 8" SCT and spend on the CCD, and I'd still end up with superior images and greater sensitivity than a 10 or 12" SCT with cheap CCD, as long as it's all well mounted.

Thanks for your opinion on the wedge, 1ponders, and yes, I wasn't thinking a $10K budget was going to be plush, I'm thinking it'll be a squeaze to get what I want for 10, and I may have to make sacrifices such as aperture for CCD quality or aperture for mount affordability etc. Probably can't blow the budget though, or my wife will have me mounted.

I've heard the Losmandy mounts are good (though their goto gear seems overpriced, but what what else does one expect), never heard much about Skywatch mounts though, and never heard any real praise for Celestron one's either so tomorrow I'll look into these a bit more. Any other's I should be aware of?

Any other suggestions regarding OTA other than Meade 8" to 12"? Definitely not Celestron 11" from what I hear, but are there other equivalent viable options? (I know you probably love your dob, ving, but it's just not gonna happen so don't even suggest it, thanks for the welcome though.)

Thanks for the links acropolite, I'll check them out tomorrow.

Thanks all and tell me more guys; too much info is only going to sratch the surface.

Daemon.

[[1ponders]]

Well Daemon, if you talk to our mate Robby here, he'll sing the praises of the Celestron 9.25. I considered buying it but it was beyond my budget for combined equipment. Apparently its one of the best for the cost.

Yes a good quality dedicated astro CCD will give better performance than a Digital SLR, and yes the B&W using filters would be the prefered way to go. Everything else is basically a cost compromise. If you can afford the double chip ccd then from what I understand its the preferred way to go. Helps deal with the issue of mirror shift with scts. However if you aren't interested in a widefield refractor to piggyback for imaging as well as guiding then you can go for any old refractor as long as it takes a 1.25" eyepiece so you can mount a ToUcam for guiding. If you get an LPI for guiding then you can even get the elcheapoest refractor with a .925 eyepiece sleeve as it will fit after removing the 1.25 adapter.

I'm sure Eddie T or some of the others that have CCDs will pipe up here, but from what I remember the SBIGs etc are somewhere round the 11mp range whereas the DSLRs range from about 6 - 8.2mp??

Hope this helps

If you like the Losmandy but not the goto (neither do I for the price) then maybe consider an argo narvis.

[seeker372011]

The Canon 20Da (astrophotography model) was launched in the US last week..till now it has only been officially available in Japan. No prices were announced-some dealers were taking orders at $2100 (US) tentatively..could even be priced at $2400 or so.

These babies are not cheap.

There are some other options, that may be worth considering

the new SAC 10-yet to ship , though orders are being taken-looks like pretty good value (US $999)

Also Atik (www.perseu.pt) have launched a single shot colour CCD , Peltier cooled at Euro 1799. Of course you would need a guide camera and scope with these.

[Jonathan]

Welcome to the forum Daemon.

Just wordering what you've heard about the Celestron 11" that makes it not an option? I ordered one a couple of months ago and should have it within a week or so and from all the reviews I read before ordering, it sounds like a very good OTA. In one review I saw there was a side by side comparison with a Meade 12" and it outperformed the Meade (not by much though). The Celestron is also cheaper at $3000 (with XLT coatings) and the Meade 12" with UHTC is $3740.

Good luck with your choice. :)

[Daemon]

Sorry Jonathan, I wasn't meaning to worry you. I have nothing definite to go on, but of all the Celestron SCTs, the 11" is the one people most commonly moan about. There seems to be a widely held view, that it is not up to the standard of either their larger or smaller SCTs in their range. Common moans seem to be lower optical accuracy, disproportionately large central obstruction, it is sometimes accused of sub standard build quality while the other sizes are praised. It's the one Celectron SCT that the Celestron fans don't seem happy with (I wouldn't waste time crediting complaints by people trying to laud Meade or something). This may all be rubbish, or it may be a quality control problem that's since been delt with, I just don't know, but when a concientious ametures offload their 11s and go back to 9.25s, I'm not personally inclined to doubt them enough to make a trial of the thing myself. Obviously your commited to the 11, and I'd be interested to hear your opinion of it compared to other SCTs you've used or owned.

Thanks for the Argo Navis tip Paul, I'd heard of it but never bothered looking it up. Definitely worth some thought.

Does anybody have any thoughts or opinions on the Celestron equatorial mounts and goto units? Seem more expensive than Losmandy, which surprised me.

Does anybody have any thoughts, opinions or experience with the Vixen SCTs. So far as I know they don't make bigger than an 8", and their optical system isn't pure SCT (something different about it) but I don't know more than that, and that their refractors have a reasonable reputation.

[Jonathan]

This will be my first SCT so it's all new to me. Striker may have an opinion as he's gone from a 10" Meade to a C11. There's a comparison of a few mounts in the current edition (July) of AS&T magazine, it's a little brief though, but it may be of some help to you.

[Striker]

I find the Celestron to be a lot better then the Meade 10" for optical quality.....I can not base this opinion on too much as I havn't had the chance to do a lot of observing since I have had it....but just going on the 2 main targets of Omega cent(5139) and Jupiter their is no doubt I can see more detail with the C11 then the Meade 10"...another thing to add to this is I am using the 99% reflective dielectric 2" diagonal on the C11 and was only using the standard 2" meade diagaonal I think 87%reflective on the Meade.

I actualy like them both..I dont think their is a real lot off difference with both..if the Meade was 11" I'm sure It would be perform about the same...so saying that the Celestron is more cost affective.

[Brendan]

umm hi daemon, like ving just a push to dob guy myself. so welcome.

[JohnH]

The $10k budget puts the new Meade RCX in play - just, AU$8.5 for the 10"...just a thought...

[Daemon]

Hi JohnH

I would want to wait a while and see what the user concensus on the Meade's supposedly RC OTAs is first, but since I'm not planning on a spend for 6 to 12 months, that's not a prob.

Is that $8.5K for the OTA or OTA + alt az goto mount?

I've seen a couple of test comparisons of optical performance of the Meade RC vs RCOS RCs, and they were not impressive, but at a third the price what do you expect: pretty meaningless comparison really. What I have yet to see is a comparison between Meade RC and any of the mass market SCT OTAs (esp Meade and Celestron). This would be a very important comparison.

However, pure RC optics doesn't need a correction element, and the Meades use one. Makes me wonder why, is their mirror geometry dodgy, are they not truly primary secondary hyperboloidal, or is their astigmatism so bad that a normal corrector can't fix it?

As my imperfect understanding sees it, for the huge price jump from SCT to RC optical config, you go from SCT potential minimal chromatic ab from the front plate (much smaller than Mak Cas and usually unoticeable) and very minor comma at field edge, to astigmatism at field edge and no potential for chromatic due to no front glass with RC (and advantage the Meade's RC gives away for reasons they don't adequately explain). I'm not convinced it's worth it from the perspective of CCD imaging (big science instruments went to RC because of benefits of position measurement at high accuracy allowing for astigmatism, over dealing with comma). Always more to learn though, might change my views yet.

[JohnH]

Agree that waiting is the name of the game with the RCX, the price I quoted is the one advertised by Bintel and is inclusive of the ALT-AZ mount but not the wedge. I take your point about the desgin - it is not pure RC however it seems to give most of the benefits and having a corrector plate has some advantages as well as disadvantages. We will have to wait and see and judge by the results rather than speculation. There was a preview in the May edition of AS&T...sounds promising...

[Daemon]

I'm certainly not going to poo-poo the product before it's had a chance John, and I'd be the first to point out that most of the unfavourable comparisons are to equipment that costs as much as a new family car; not valid comparisons at all.

I've heard others say the corrector plate may be a good thing, but nobody defines why. Do you know, or have a link to, anything that explains what benefit a front corector can be to an optically good RC? It'd be better to know a bit more, rather than just assume it's to correct some nameless optical ill.

Daemon

[JohnH]

Thre only pro I can see is the plate seals the OTA and keeps the mirror clean. Other than that I believe the hybrid design enables Meade to keep costs down, it is easier for them to produce optical performance by using two elements mirror/plate than one (mirror only) as in a pure RC design where mirror is difficult to manufacture (costly).

[Daemon]

Can anybody give me some links to comparitive reviews on:

Celestron vs Meade vs any other comparable medium SCT

Losmandy vs Takuhashi vs Vixen/ Celestron & other mounts

Not after feature comparisons like the AS&T review, more after quality and useability comparisons and critiques.

Thanks guys.

John, after thinking about it, I think I'd go for the front corrector, even if it was just a high quality flat clear, simply to avoid the diffraction spikes of a spider; definitely looking forward to seeing a road test of one of these things. The Meade RCX focussing system sounds very attractive too. Can't find anything that even hints these will be available as OTA only, or on anything other than the fork mount though, and even with the improvements in the Meade mount and wedge they're touting, it's hard to believe it'd equal a half reasonable GEQ for stability and tracking accuracy re long exposure CCD.

[xstream]

Daemon,
If you want to know a bit more about the RCX400, I'd suggest going to the Users Group :- http://groups.yahoo.com/group/RCX400
You will find a wealth of information there about the RCX; also that it's claimed, it is not an RC but an advanced RC design. Which that statement seems to create enough debate on it's own. Those that already have recieved the scope seem to be more than impressed by it's capabilities.
Also I wouldn't envisage it being available in Aus. till sometime in the New Year.
Hope the link is of some benefit in you making your decision. :)

[JohnH]

Daemon,

Are you still looking to find the best solution budget and imaging interests, I know I am. Now there are new Synta products coming available HEQ5/EQ6 Pro (inc SkyScan) and a range of OTAs to put on them, the ED80 is given a new paint job but more interesting from my pov is a range of big Maks topping out at 203mm. I like my little etx90, I was thinking to go for a SCT next but...Maks seem to be rated highly, there are some pros/cons but in general the Mak seesm to be regarded as shaper and brighter than a SCT of the same appature. This is I believe, mostly due to the smaller central obstruction in the design. The main drawback is weight (thick corrector) and thus poor thermal characteristics (long cool down times) with larger Maks. Do I have this right? Can the experts out there comment - would you go for a 7-8" mak over a 8-9" SCT?