Future SCT thoughts

[sejanus]

hey,

for those that have not followed my newbie entry into the arena,i bought a ed80 and the skywatcher eq6 mount and although i haven't got much use yet I'm just a bit bored at work and musing over my future plans. ;)

the plan is to keep using the Ed80 for astrophotography when I get experienced enough, but I do want something with a bit of size for visual observing for funs sake.

I was going to go down the meade route but recently found out that apparently the celestron sct's are a bit lighter, which may be a factor with my mount? Although bintel seem to think the eq6 with the 80ed + a 10" sct will be fine.

I don't mind spending a bit of cash as this is something that should last me a heck of a long time. obviously buying as an ota.

So the options appear to be ;

Meade 8" LX200R
Meade 10" LX200R

or

Celestron CPC11XLT 11"
Celestron 9.25"

What would you do in my scenario?

I've got a big chunk of annual leave over dec/jan and have an evil temptation to buy it to have it arrive by then although I will do my best to somehow try and look through some first.

cheers

[mick pinner]

it would seem that the C9.25 is the scope to go for at the moment, light weight compared to the Meades and also very good for astrophotography, l personally have not looked through one but by the comments of new owners they seem very good and probably the most reasonably priced scope in that aperature range.

[casstony]

I've seen a few recent reports indicating that celestron optical quality has dropped a bit recently. Matt got a 9.25 lemon before having it exchanged for a good one - he indicated he might be selling this and asked for expressions of interest recently.

[g__day]

My C9.25 CF XLT seems all that I expected, arrived last week. I piggyback a Megrez 80mm on it.

I think the 10" Meade LX200R or the Celestron C9.25 XLT are scopes that often get rave reviews - and deservedly so. But astro-photography is something best suited to start on a 80mm scope I'm informed.

But my advice would be read alot - there are many posts on this website, because the range of scopes you consider are tools to achieve a purpose. Different night sky quality and difference focal lengths will affect what you can see and how good an autoguider you may need.

As one who's recently started - there's alot to learn.

[sejanus]

I've been reading heaps.

Something I've seen a bit is the celestron 9.25 gets a better rap than the celestron 11" - but aperture should win right?

[casstony]

Especially for visual use, if you're happy with the extra weight go for the bigger aperture, otherwise you will always be wondering about those missing photons. If you later decide you don't like the C11 it should be fairly easy to sell - I see very few used C11's for sale.

[g__day]

The C9.25 has a flatter field of view (due to the size ratio of its primary mirror to its corrector plate) - making it better for astro-photography, the C11 has more light grasp - so its a trade off. Do you want more light for fainter objects or a flatter field of view? Better explained here: http://www.cloudynights.com/item.php?item_id=1528

But a side by side comparison of the two is worth reading too, here: http://www.cloudynights.com/item.php?item_id=1464

[sejanus]

interesting article.

The C11 is some serious dollars though! by gosh.

$4800 for the CF OTA. As a idea the 10" lx200r from bintel is $3300.

[sejanus]

a good point. I hate the "what if" feelings after you buy something.

[casstony]

Sejanus, I'd say you have about 35 more to's and fro's before you figure out what to buy (speaking from experience). Check http://www.andrewscom.com.au/site-section-10.htm for celestron pricing (C11 cf $4300).

[g__day]

Suggest you consider buying from someplace more reasonable then - e.g. MyAstroshop or Andrews Communications...

Andrews

C9.25-A OTA only...$2699 AUD
C9.25-CF Carbon Fibre OTA only...$2799 AUD
C11-A OTA only...$3499 AUD
C11-CF Carbon Fibre OTA only...$4299 AUD

MyAstro probably will be similar or within Cooee of Andrew's prices if you ask (they all buy from the one importer - Luke at ExtraVision Queensland). The only really dear retailer is Astronomy Online - guess the rental near Warringah Mall is a killer.

I got my C9.25 CF XLT OTA from MyAstro. I figured a $100 price differential between Aluminium and Carbon Fibre was a great buy, vs $800 difference once you go up one aperature size is outrageous!

So if you think the choices are 9.25" CL for $2,800, 10" for $3,300 or 11" Al for $3,500 should should be able to figure a sweetspot pretty quickly! All should be tremendous scope, mounted on the right equipment and upgraded with a better than supplied diagonal and finderscope!

[sejanus]

thanks heaps for that

it was actually myastro that quoted $4400 for the C11 (non CF) or $4800 for the C11 with CF, so I guess andrews gets a better deal.

more worryingly though i just called andrews and they have a 9.25 in stock and a c11 due in a few days which will concern my wife when she finds out :lol::thumbsup:


Bintel has had a price drop it seems as well, the 10" is now $2995. The 12" is $4400 but i doubt my eq6 could support it anyway :eyepop:

The reason for such a large scope even though I'm a newbie is I want to keep this thing for years and years.........do it right the first time sort of thing

cheers

[g__day]

12" OTA - circa 18Kg - the 200R may be heavier - an EQ 6 is rated to 25Kg

http://www.astronomyonline.com.au/Default.aspx?tabid=107&forumid=24&threadid=37&scope=posts

a guide to scope weights and costs vs goto mount weight capacities / cost / pointing ability

Note don't load a mount to capacity if you want great astrophotography - maybe keep it to 70% of its load limit I've heard.

[sejanus]

great link. think the meade 10" price is wrong though, at $2085 I'll have 2 thanks :) it's currently $2995 at bintel.

thanks

[g__day]

The Meade price there was Bintel's price for the 10" 200 OTA not the 200R OTA which is a more modern design with I'm told better optics (closer to a RC design - but like all Meade's - even the RCX400 not a true RC I see on dedicated RC designs - which have no initial lens ) so it has a more significant price - sorry didn't update that old link's data, the plain 200s stopped being available in early July this year.

I don't think Meade sell the LX200 OTA anymore - mores the shame, and the focal reducers of the 200 do not work correctly on the 200R be warned!

PS

A true RC design vs a Meade or Celestron closest, "cheapest" approach http://www.rcopticalsystems.com/overview.html or what a real RC looks like, why its better than the popular knock offs and why it costs around 3 times more at least!

[sejanus]

The C11 is listed at 13kg but do you remember if that was the aliminium or carbon fibre version?

[jase]

The Celestron carbon fibre 11" is 12.3kg (stripped i.e no finder scope or mods such as bobs knobs or larger visual back).

[sejanus]

thanks jase

couple of questions for anyone :)

I see reports on CN forums of guys with the 10" and 11" SCT's saying that most of the year they get fairly soft observing results, and there are only a few nights of the year when they get really sharp results.

Do you think this is because they live in pretty poor areas lightwise? I live about 45km from the city and there isn't a massive amount of light pollution where I live, I can clearly see the band of the milky way, and most stars are bright. actually late at night I couldnt even count how many stars I can see. You think a 10/11" would be ok in these sort of conditions?

cheers

[casstony]

The amount of light pollution has no effect on the sharpness of the telescope. Light pollution just makes it harder to see dim deep space objects, especially galaxies.

The sharpness of your scope depends on the quality of the optics, collimation of the mirrors, and having the scope fully cooled to ambient temperature(which can take some hours). Once those factors are under contol, the stability of the atmosphere will determine what magnification you can go up to while still having a sharp image. By using your ed80 frequently you'll get an idea of the level of magnification you can typically expect to get in your area.

If the stars are twinkling crazily you'll be stuck at low magnification (say 60X). If the stars look very steady you'll probably be able to go to higher magnifications. Regardless of all this, a larger aperture will let you see DSO's better.

[sejanus]

they complain of a lack of contrast - wouldn't the glow from light pollution cause this - at least to an extent?

[casstony]

Light pollution does reduce contrast but it mainly affects DSO's. A dark sky will give great views of DSO's; a stable sky will give great views of planets. You could buy a 10" dob for $700 to check all this out for yourself - the ota could be mounted on your EQ6 or used on the dob mount - and you would probably have better optics than the SCT.

[casstony]

Strike that last post. SCT's are much better than dob's. I'm envious of that large Celestron box on your floor :-)

[sejanus]

lol

I'd love a dob but it's just not realistic size wise. I know i could get/build a dob that would flog the sct in terms of size/aperture but it would just be too big to manage.