C9.25 or C8

[asimov]

Hi guys.

I'm heading down the SCT track soon (real soon :D ) And was wondering this:

My ideal SCT would have to be the C9.25 OTA only, based on (LOTS) of reviews & photographs posted by guys such as Robert_T/Rumples/Dennis & Matt, to name but a few.

$2300 + shipping AU & it would fit snugly on my motorised EQ5 like a bug in a rug :D

I also have the opportunity to purchase a second-hand 10 yr. old C8 OTA only...for a THIRD of the price of the C9.25 (the black one with the orange 'CELESTRON' on it) Which supposedly has 'fine scratches' on the corrector plate..Would this be a concern, these fine scratches??

Whatever I purchase, I will only be doing imaging with it, very little visual stuff.

Also, please bear in mind I know NOTHING about SCT's. Never even seen one before except in photo's.

Can anyone tell me about this Black tubed C8 ?

Any help appreciated & comments welcome. :thumbsup:

[Neilzstar]

Have a black tube Celestar 8 deluxe (since 1995.) It was at SV last week. Has excellent optics by ronchi test. Mine is fork mount which is a bit touchy but settles quickly. But you won,t have that on the EQ. regards, Neil

[Robert_T]

Hi Asi, I think Houghy bought one of these recently so perhaps he can comment on how it is. I know there was some vintages of the Celestrons when the optics were less that ideal.

Me personally, I'd be wary of second hand optics. I like the protection of a warranty if things turn out not to be quite right (I have made use of this in the past). I think for a planetary scope you need the optical quality to be particularly high. Perhaps fine scratches are not of concern, but it makes you wonder if the scope has been well looked after etc. Recent Celestron optics have achieved a good reputation and the C9.25 rates very highly on quality. In star tests the c9.25 I bought seems pretty close to the Mewlon which has 1/20th wave optics.

I guess it's always a bit of a gamble whatever you do and a compromise of money versus performance etc... I'd love to have a Mewlon 250, but at $10,000 for the OTA I was happy to compromise on the C9.25 - in terms of performance per $ I reckon it must be in front.

cheers,

[davidpretorius]

know nothing about 'em, but i would love to see you with a newie mate!

Loved pauls at snake valley, a fine piece of work and the optics were fantastic.

Pauls, Dennis and Rob's jupiter videos seem to be 3d straight out of the box. Better than the 10" gso dob I believe.

[asimov]

Trying to find a review on a black C8 OTA about 10 years old is like trying to find a needle in a haystack:(

My biggest dillema is moving to the USA in 12 mths or so.

Do I buy the C9.25 now & sell it again, or do I ship it with me which could cost, I dunno...$400 ??

Hence the idea of perhaps going second hand.

[Robert_T]

Here's the deal, Asi buys it and uses it for 12 months then sells to DP before winging over to the US and buying himself a C14 on a CGE mount for the same price.... well, Ok maybe a stretch, but you could buy a new C9.25 over there for much the same what you'd sell it for here second hand :D

[Hitchhiker]

http://skywatch.brainiac.com/used/used_sct.pdf

This is a large pdf document (about 5 Mb) but reviews all older model SCTs.

[matt]

And just wait till I get a night or 2 of equally good seeing, DP...

then you'll be able to count me in that list:P

[davidpretorius]

don't they keep 80% of their value????

Matt, you simply better move state & if you do, you are a shoe in!! Whilst the politicians are there, far too much hot air causing inversions and porr seeing!!!

[asimov]

Comments Dave, hmmm??

Actually, I've already run that scenerio past Dave. ;)

[asimov]

80% of value? I have my stuff forsale under 50% & can't sell anything, lol.

[h0ughy]

ASImov,

my scope is a little beauty, circa 1990's, the person who I bought it from looked after it very well. I know the scope you are looking at, you will have to get a finder scope for it but for $600 it is a good buy and learn from, and you can modify it without crying!

[asimov]

Yeah, I figured someone would know exactly what C8 I was looking at.:)

A bit worried about the scratched corrector though.

Thanks for your input mate :thumbsup:

[h0ughy]

Did they supply an image of the corrector? generally you will not notice the little belmishes, unless it is the size of a bus.

All my SCTs have marks of some description:)

[asimov]

I've requested more images, particularly a close-up of the corrector. Not received yet.

[netwolf]

hmm i wondered who would scoop that up, its possible the Telrad i got was of this scope too. There is also a C11 going fairly cheply at the moment. Well if you do get it Asimov, you may have a buyer for it in a few months time cause i cant afford it right now. Just got me P's (late learner) and have to buy a car.. oh the pain the pain..

Regards

[sheeny]

G'Day Asi,

If I was in your position, Asi, I think I would go with the C8, with the aim to sell before I left to go OS, and aim to buy a 9.25 when I got to the states.:thumbsup: That way you'll get to know your way around an SCT, and probably not lose too much cash in the process...

As for the marks on the corrector plate, my scope is less than 12 months old, and I remember when I first got it, the corrector plate was so clear and blemish free that I had real trouble seeing it! But now there are little blemishes and marks all over it, and the only thing that has touched it is dew and whatever dust happens to find it's way there. I use a real gentle air blower to remove any dust I can, but based on advice I've picked up from this forum I'm resisting the temptation to wipe it. So I guess, I'm suggesting that if it has XLT coatings they are easily marked, but whether or not those marks are significant in terms of image quality you probably won't know till you test it. But I suggest the marks would have to be pretty bad before it'll worry the image...

Anyone have any better experience?

Al.

[asimov]

Thanks for your wise comments Al. I'm actually thinking of doing just that....As much as I REALLY want that 9.25, I think it would be smarter to get it in the States.

Cheers.

[acropolite]

I wouldn't be happy with the scratches they look fairly extensive, like the corrector has been cleaned with something very abrasive. I would go with the c9.25 if you have the money, you'll never say you wished you had bought the 8 inch.

[h0ughy]

I cant really define anything too bad there, but as for the re aluminising, if the scope has been sealed, I woud say not needed. Offer him $500 plus postage bottom line take it or leave it;)

[sheeny]

I agree with hOughy... can't see anything too bad in the photo, but if I was buying it I'd like to test it. Do you have access to it so you can test drive it?

I can appreciate acropolite's comment about you won't regret not buying the C8 if you have the 9.25, but I don't know, maybe it's just me... there's something about taking a Celestron scope to the States that seems like importing a Holden to Australia... It just makes more sense to me to buy one there.

Al.

[Robert_T]

Asi - it actually looks pretty Nasty to me:scared: . It's hard to tell how much impact it will have, but it can't be good to have that degree of scratching for what needs to be a high res high contrast planetary scope. Looks like someone might have taken my "wipe 'er clean with the end of a well chewed stick" to heart on this one.

cheers,

[asimov]

Yes, I hate looking at the pics, the more I look, the more I see! A pity really.

I want zero adverse 'impact' on my imaging if I'm to keep up with the big boys of planetary imaging..;)

The things in Perth & I'm in SA unfortunately Al. No test drive. I actually agree, it makes way more sense to pick up the 9.25 in the States when I get there. I'll have to come to a decision my usual technical way...best out of 3 flips of the coin wins. :)

[sheeny]

:D If that doesn't work, Asi, go for the best of 5... best of 7...

Maybe I need to get a better monitor at work... I can't see much in the way of scratches in those photos! (And I cleaned the screen too!!!)

[davidpretorius]

what does a c9.25 cost in the states??? what does it cost here?

how are you getting your gear to the states anyway, a container???? or is there not much that will be going??

paul's boxes were very good for his c9.25 and very easy to transport.

sorry for adding more confusion!

[Stu]

That amount of scatching is not going to make any difference IMO. You would already be buying the scope type with the largest stray light anyway.

I can't find the review now but someone in the USA stuck a postage stamp on the front of an SCT and took heaps of images. Couldn't tell the difference with or without the stamp.

I think the C8 is a bargin and you still not have to stress about moving it OS because you will easily get your money back. I'd get it.

[allan gould]

I would get the 9.25. Ive known several people that have gone from 10" and 12" scopes to the 9.25 due to better optical performance.

[Robert_T]

Hi Stu, stray light indeed, you've been spoiled by apos haven't you ;)

It doesn't suprise me that you could have a postage stamp on a corrector plate without much impact as it would be much like an aperture mask. Corrector plates can have a lot of crud on them without much noticeable impact I suspect because this mostly blocks rather than scatters light. Scratches on the other hand (and when I look at the images here all I can see are a mass of very fine scratches all over the plate with some larger ones that really stand out) I think are more likely to scatter the light and reduce contrast and sharpness more than anything that simply blocks light.

That aside I also feel it depends on what the intended use is. It might not have any noticable impact on low power deep sky imaging, however, high maginification planetary imaging is extremely demanding on optics, collimation, figures etc and when you're trying to extract that extra 5% from your scope scratches like these might make all the difference.

Asi - as Houghy suggested you could always make a low offer... or you could buy and sell something new, maybe even a C8 new if you want to save some moola and get the 9.25 in the states?

cheers,

[JohnG]

Those scratches are radial, it looks like someone has attempted to clean the corrector with a cloth of some kind, it will cause a lot of light scatter and as such will be very difficult to get a contrasty image on planets, it would probably be OK on DSO's though.

JohnG

[h0ughy]

Lotta talk here Asi:D

lotta experts with lots of opinions:P . Wearing your gum boots:lol: to wade through the debate?

a new 9.25 is about $2250-2500 ota only a new 8" OTA is about $1600-1900. So for 600 dollars there is a lot to be said for justa a few scratches. i doubt you would notice it. i think most of it is smeering with a few genuine scratches that i am sure you could live with. are they the only picts he sent of the ota?

only for the fact I already own an C8 i would buy it, if i was in the market for looking. I have owned several SCT scopes. the other extras you would be after is a set of mounting rings or mount bar for the scope. I think they are about 130 for a mount bar - try andrews or bintel?

Asi only you know what you really want:thumbsup: ?

[asimov]

To boil it down Houghy, I want images like dennis,Rob,Matt,.....DAMIAN PEACH!! :D If I could be guaranteed the C8 is going to give me that, I'd snap it up in an instant! But it's $600 ($500 maybe) to find out.

If I bought it & had problems due to the scratches, I'd be very annoyed & not to mention the fact if I tried to sell it again, most would think I'm selling it because the scratches had an adverse effect on imaging! Probably have to give the damn thing away.

Nah, I've decided it's not worth the 600 buck gamble, someone else can do that. If it turns out I missed out on a truly great bargain, I wish the person that buys it great imaging! (And I'll be kicking myself for months after though:doh: :screwy: :lol: )

C9.25 it is! At least I can send that one back if theres a problem. Ok, I've chosen the scope of choice....now I need to decide WHEN! :eyepop: Now, & use it for 12 months (approx.) then re-sell or ship it over. The choice is simple when thinking about the money hey!? :thumbsup:

Unfortunately I'm totally DRIVEN/HOOKED/POSSESSED BY THE IMAGING DEVIL) to getting Peach-like images now, not in 12 months time! :scared: ....Stuff it, get it now & think about that later.

Thanks guys for your input :thumbsup:

[h0ughy]

:)


Knew you would, thats why I posted what I did:thumbsup: there would be nothing wrong with this scope for a quick setup one and compact! enjoy your 9.25" Asi:D

[sheeny]

There was never any doubt, was there Asi? Based on your imaging aspirations, I don't think the C8 was in the race!:D

Now that I've had a look at the photos on my home PC, at least I can see some scratches now ...:rolleyes:

I think you're doing the right thing. If you are chasing perfection with your imaging, you wouldn't be happy with the results of that C8. I don't know how bad the scratches would be, but light scattering and contrast would have to suffer at least a bit. It might be OK for a lot of stuff, but there's a good risk it'll fall short of what you want to achieve... thinking about it, scratches are optically different to dust and blemishes...

Enjoy the 9.25!

Al.

[acropolite]

Well decided Asi_imager, I wish I had started with that OTA myself.

[davidpretorius]

well done asi!!

[asimov]

Thanks.

BTW I'm ONLY buying this to give you SCT (& Dave) boys some incentive to get better images! :D It's not for my benefit at all :whistle: You've all been a bit slack lately with your images! :poke: Time to pick up your game a bit! :P

Let the imaging wars...BEGIN!!! :eyepop:

[asimov]

A quick Q for the SCT guys: I'll be mounting the 9.25 on my driven EQ5 (with the steel legged tripod) which is what Robert did, only he has the pier under it. How does one balance the scope out on the DEC axis if you can't move the OTA up or down in a cradle.....counter weights?

[matt]

Congrats Asi

You won't regret it.

Yeah, counterweights are the way to go. Also, the scope comes with a mounting plate which should enable you to slip it straight into the head of your mount and tighten the screws on it.

or, at least my OTA did. A nice pretty orange one:lol:

[asimov]

Yeah, I knew it came with the dovetail plate Matt...I think I'll have to paint it! Terrible colour.

[Robert_T]

Fantastic News Asi! :) With the skills and techniques you've developed to wring amazing results from that 6 inch acro, you should really be able to make the c9.25 sing. :thumbsup:

As for balancing in declination the OTA has a full length dovetail plate, so if you're eq5 is like mine you should be able to simply loosen and slide it back and forth to balance as required.

cheers mate,

[asimov]

Now THATS fantastic news to me Robert! thanks for that (about the dovetail plate)

Cheers! :)