OTA: Meade 10" SCT vs Celestron 9.25" query

[g__day]

Guys I'm planning my next OTA upgrade and was geared towards the Carbon Fibre C9.25" for around $2,800. The goal is both astro-photography and naked eye viewing.

A few weeks ago it was pointed out that Bintel sell 10" Meade SCT for $2,085, alah:

Meade 10" f/10 SCT OTA w/UHTC .... Primary Mirror Lock locks the mirror in place during long-exposure photography.

So my question. Which would you guys prefer and why? I'll probably piggy back a ED80mm refractor on the mount and next year go from a CG5 to a Losmandy G11 + Gemini, then eventually save to get an S-BIG.

But if that's the route I'm heading what suggestions would you have, and how would you compare and contrast these two choices?

Many thanks,

Matt

[Harpspitfire]

i got the 9.25 after reading considerable reviews and OTA specs a few years ago, to this day i have no regrets- im not sure id want the CF tube though, i know theres been debate over this, but i feel its just a heat trap- i got the aluminum tube, i just felt metal is a better conductor and would throw off the heat quicker then the insulation properties of a CF tube

[Striker]

I did a fair bit of homework regarding the Carbon fibre OTA and most reports were to stay away from them...the carbon fibre OTA trapped heat causing a slower cool down time...carbon fibre is the perfect material for open truss designs not closed units.

Some reports come back saying they worked fine in areas that dont have extreme temperture changes so if you climate doesn't differ to much from day to night then some had success using a SCT cooler.

This info was reported back to me through reviews I have never used a carbon fibre OTA.

You cant go wrong with the C9.25 OTA..I think it's slightly ahead of the 10" Meade LX200.

[Dennis]

I have the C9.25 XLT CF and the main reason I went for carbon fibre is mechanical stability related to thermal changes. I don't have a temperature compensating focuser so the feature of CF that attracted me is that it expands/contracts less than aluminium, so I wouldn't need to touch up the focus as often when doing all night imaging sessions.

It looks sleek and sexy too!

Cheers

Dennis

PS – Striker’s Meade 10” RC looks a cracker of a ‘scope from the images he has been posting.

[casstony]

C9.25 has flatter field, wider zone of critical focus making focus easier to maintain, and is 3 or 4 kilo's lighter than the Meade 10".

I don't own a c9.25 but I've been looking into purchasing the c9.25, c11 or meade10". The c9.25 has a cg5/vixen style dovetail. The meade has some weird dovetail that doesn't seem to fit anything. Meade has been having more than their fair share of quality control problems recently(related to poor assembly rather than optical quality).

There doesn't seem to be a consensus regading CF vs Al. I'm concerned about the insulating properties of CF in a temperate climate.

Tony

[Dennis]

My C9.25 XLT CF optical tube assembly came with the Celestron CGE mount dovetail rail as standard, which fits the Losmandy system. I think the non-CF OTA's come with the Vixen style dovetail rail.

Cheers

Dennis

[g__day]

Taa, thanks,

Ignoring the Carbon Fibre vs Aluminium, it is is a $2K 10" Meade vs a $2.8K 9.25" Celestron a good proposition? The wider fireld of critical focus seems encouraging to the Celestron.

A 10" SCT has about 15% more light gathering than a 9.25" Scope (up to 19% if Meade using 10.25 over-sized mirrors is true), has mirror lock for long duration astro-photography and is $715 cheaper than the Celestron, but weights 14Kg (2kg over what I believe a CG-5 should be carrying normally. let alone for astro-imaging) or 5Kg more than than the Celestron, far better within the CG-5's carrying capacity.

The Celestron 9.25" and 14" get rave reviews for astro-imaging at this price range, hence my query to the more experienced amongst us!

[beren]

I'm not "more experienced" but ill give my perspective anyway , im not entirely convinced the mirror lock on my LX200 is truly effective and tweaking the focus on my scope seems to be its biggest issue .Visually my 10'Lx200 performs very well, star tests seem satisfactory, stunning GOTO accuracy....with a crayford focuser the scope for an eyeball observer is a top tool.For photographic work care tends to be taken to take into account a users experience, imaging at these focal lengths is frustratingly difficult {and addictive} so my time spent on focusing and collimation might be under par then some one with greater skill.As Tony suggested in the previous post the 9.25 OTA appears to have from reputation better thresholds for focusing which seems to backed up by the splendid planetary images the 9.25 owners have achieved and displayed here and elsewhere.Compared to the images ive produced of Jupiter during this season mine have been consistently softer then theres.If I had my time again I would still definetly go for the lx200 if I was interested in only observing but for imaging the 9.25 and G11 would be the direction I would take

[Robert_T]

Hi G_day,

The price you quoted for the C9.25 I assume is the carbon fibre version. I purchased the aluminimium OTA from Andrews ~9 months ago for <$2400. If you haven't already you may want to check the $ price for the 10 inch OTA that BINTEL have on there web-site is still current too. The price differential might not be so great after all.

While the C9.25 doesn't have a mirror lock. Hutech make a focus lock (~$50) that locks the manual focus and reduces mirror movement substantially. Works well in conjunction with an electric or secondary focusser.

cheers,

[g__day]

Robert - Yes thats the Carbon Fibre price and the Bintel price was from their website 3 days ago.

What is a mirror lock by the way, and does a carbon fibre tube need it much given its extremely low coefficient of thermal expansion, or is it mirror flop caused by different angles of the tube that needs addressing?

[Lester]

Hi Matt,

From what I have seen on IIS with Meade and Celestron, there isn't any noticeable difference in quality of images produced. Mainly comes down to operator, and how they use their equipment, eg. collimated, quality acessories. The 10" will give you just over 10% brighter image at the same magnification compared to the 9.25". So with the 10" Meade being $700 cheaper to me the answer is obvious.

I have had no experience with the drives on these two scopes and that may be another important issue.

[Robert_T]

SCT's are focussed by moving the primary mirror, the mirror lock locks the mirror in place so it can't slip or flop as the tube is moved... the carbon fibre tube won't help with this.

cheers,

[Robert_T]

G-day, I've just had it confirmed direct by e-mail with Bintel that they only now supply the Ritchy Chriton version as OTA only (at least for the 12 and 14 inch versions). The SCT OTA's are only purchasable as part of an LX90 despite the web-site showing these as OTAs.

regards,

[g__day]

Well I guess they better change their website fast, or be exposed to any claim for false advertising, and be in a position where they must provide the goods as advertised for the price listed, by NSW law.

As impressive as the RC OTAs are I think I'll be heading down the C9.25 route next step.

[UniPol]

Bintel must have heard you, their site now only lists the RC's from 8" - 16" OTA's.

[g__day]

;) - they're on the ball!

Yeah the folk there read this website, and any good or adverse comments here get noted and actioned very quickly I am most pleased to say! Good onya Mike and Anthony!

[Roger Davis]

I'll tell Anthony when he's in next.
signed Anthonys boss

[scumbag1010]

Hi all,

Just to clear what appears to be some confusion in this thread.

Meade no longer manufactures the LX 200GPS (Schmidt Cassegrain)
They do manufacture the LX 90GPS (Schmidt Cassegrain)
They also manufacture the LX 200R GPS (Advanced Ritchey Chretien)
They also manufacture the RCX 400 GPS (Advanced Ritchey Chretien)

In OTA's they only have LX200R scopes in the following sizes;
8", 10" 12" 14" and 16"..

You cannot buy an SCT as an OTA. Meade does not split the LX90 GPS.
You cannot buy an RCX OTA.

So now when you buy a Meade OTA you are getting the LX200R Advanced Ritchey Chretien with its better optics, which are superior to Schmidt Casssegrain optics.

Hope this clears some of the confusion.

Don Whiteman
Technician
Bintel