Celestron C8 XLT Starbright Optical Tubes.

[Guest]

Over the  years I have seen C8 OTA's in several colours. They have been black,orange and grey. I have always assumed that they were all the same optical quality. Is that assumption correct? I have seen that the current retail for a C8 OTA is only approx £200 less than the NexStar 8SE. This comes with a goto mount for only approx £200. So is there a difference in OTA quality?

[Ken82]

Not sure about the grey but I’m sure the orange tubes are the older Schmidt tubes. These orange ones didn’t have the starlight XLT coatings but an earlier version. 
 

Optically apart from the coatings the newer versions may be slightly better with modern techniques but that is a guess. 
 

I think the only distinction is with the newer edgehd models which are better corrected for optical aberrations.  

[John]

Rod Mollise's free guide to used CAT's is well worth a read and covers Celestron and other brand SCT's:

https://skywatch.brainiac.com/used/index.htm

The change to being produced in China didn't seem to affect the quality and maybe even improved it:

 

[johninderby]

The Chinese produced ones do seem to be more consistant in quality control. The US made ones were a bit more variable. Mostly good but the occasional lemon.

In the US people pay a premium for the US made ones despite that though. 🙄

[John]

The ones produced in the 12 months before Comet Halley's return in 1986 were often poor. Apparently both Meade and Celestron relaxed quality control standards to meet consumer demands at that time.

 

[Guest]

10 hours ago, John said:

The ones produced in the 12 months before Comet Halley's return in 1986 were often poor. Apparently both Meade and Celestron relaxed quality control standards to meet consumer demands at that time.

 

At one time I owned a year 2000 Meade LX 90 8 inch. It gave great views on most objects. But was heavy and I mostly used it in a manual mode as a manual alt/az mount. Could never find just the tube assembly. Wonder if the current Celestron C8's give reliable good quality?

Edited June 13, 2020 by Guest

[John]

If you buy new, and there is an issue with quality, at least you have some redress.

 

[johninderby]

The latest C8s are excellent quality and not heard of anyone getting a bad one. 

[Alkaid]

I have a grey one. It has Starbright coatings, these preceded the newer Starbright XLT coatings. The newer XLT’s have a bit more light transmission but it’s a small increase, about 10% or something like that. Would help a little on DSO’s.

I’d say mine was a ‘good’ specimen, views of the Moon at x220 are sharp and ‘hard’ ( no softness in the image).  I pushed it to x480 for fun one night and it ‘just’ (by skin of its teeth) held a reasonably acceptable image.  I don’t have an eyepiece combo that will do a more acceptable x250-300 but I reckon that in good seeing it would deliver.  However, good seeing where live is rare.  x220 is generally the max I go to and the view of a crater like Copernicus is fabulous.  

I haven’t a clue if it’s a US or Chinese one, but I too have not heard of any complaints with the newer Chinese model.

[Guest]

I forgot that there was a dark grey colour tube. I was probably thinking of the lighter grey or silver colour tube which has Starbright XLT coatings.

[Highburymark]

There are only two versions available today, the standard C8 and the Edge.

Standard C8s come in black, grey (usually if bought with Evolution mount), or orange (as part of Nexstar SE package).  These are all the same otas.

The C8 Edge has flatter focal plane, vents, mirror clutches etc.

If buying one second hand I’d try and test it first. Some C8s deliver tighter stars than others. 

[Alkaid]

On 14/06/2020 at 15:43, Highburymark said:

There are only two versions available today, the standard C8 and the Edge.

Standard C8s come in black, grey (usually if bought with Evolution mount), or orange (as part of Nexstar SE package).  These are all the same otas.

The C8 Edge has flatter focal plane, vents, mirror clutches etc.

If buying one second hand I’d try and test it first. Some C8s deliver tighter stars than others. 

You’re describing the new ones, all Chinese. Unfortunately the history of the C8 is so varied that it can be rather hard to find out what era an older one came from. Before a certain year, they were made in the US, in all of the colours you mention.

[Highburymark]

4 hours ago, Alkaid said:

You’re describing the new ones, all Chinese. Unfortunately the history of the C8 is so varied that it can be rather hard to find out what era an older one came from. Before a certain year, they were made in the US, in all of the colours you mention.

Wouldn’t want to claim anything different - that’s why I said versions available today.

[Alkaid]

12 hours ago, Highburymark said:

Wouldn’t want to claim anything different - that’s why I said versions available today.

Ah, gotcha - apologies for misunderstanding.

I must admit that I would like to try an Edge someday, but I would love to stretch to the 925 if I could.   It's rather pricey though...🤔