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Old 05-04-2024, 04:26 PM
Allan3026 (Allan)
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SCT lifespan

Hi All
I'm considering buying an older SCT, and was wondering what the lifespan is for these scopes. In particular, do the mirrors degrade substantially over the years? Should I stick to under a certain age?

I've had Dobs in the past , 1 of which degraded badly and ended up in the rubbish. SCT,s being somewhat sealed should last a fair while longer I imagine.
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Old 05-04-2024, 05:26 PM
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Hi Allan,

I recently bought an older black tube C8 with Starbright coatings that I believe is from '80s. There is no degradation evident in the optics and it performs well.

Of course the older optical coatings are less efficient. I think Celestron's Starbright XLT coatings transmit around 10% more light than the original Starbright.
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Old 05-04-2024, 06:22 PM
Dave882 (David)
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The c14 I use for most of my imaging and visual astronomy is a 90s black tube and thereís no noticeable degradation. However I will say there are some advantages of new versions:
- slightly more efficient coatings
- better focus mechanisms and less mirror shift
- fastar compatibility to attach a Hyperstar
- less chance itís sustained damage during cleaning or general use

But I donít think any of these are deal-breakers. A good sct will stay a good sct for a long time if itís been well cared for.
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Old 06-04-2024, 10:29 PM
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Quote:
Originally Posted by Dave882 View Post
But I donít think any of these are deal-breakers. A good sct will stay a good sct for a long time if itís been well cared for.
Dave882 is absolutely correct.

I purchased a C8 in 1986, one of the very early Starbright scopes. It was a US$300 optional extra back then. I've always taken care to kept the scope dry when stored. I had the main mirror out just recently and it still looks pristine.

Chris
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Old 11-04-2024, 03:43 PM
Allan3026 (Allan)
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Thanks for the re assurance. Good to know they last. Now just need to decide between C9.25 and Meade 10".
I do like the Hyperstar option, so leaning towards C9.25.
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Old 11-04-2024, 04:07 PM
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Quote:
Originally Posted by Allan3026 View Post
Thanks for the re assurance. Good to know they last. Now just need to decide between C9.25 and Meade 10".
I do like the Hyperstar option, so leaning towards C9.25.
Might want to check the weights. Meade SCT's tend to be heavier than Celestron SCT's of the same aperture.
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Old 11-04-2024, 05:06 PM
Allan3026 (Allan)
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Might want to check the weights. Meade SCT's tend to be heavier than Celestron SCT's of the same aperture.
Thanks, good to know. I have an AZ EQ5 that will be used for visual. My plan was an older (Cheaper??) SCT to put side by side with my 4" APO for EAA

Older C9.25 means no Hyperstar.
Older Meade 10 sounds too heavy for my AZ EQ5.

Probably for another post, but is Hyperstar good for fast images with EAA?
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Old 11-04-2024, 05:07 PM
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Quote:
Originally Posted by Allan3026 View Post
Thanks, good to know. I have an AZ EQ5 that will be used for visual. My plan was an older (Cheaper??) SCT to put side by side with my 4" APO for EAA

Older C9.25 means no Hyperstar.
Older Meade 10 sounds too heavy for my AZ EQ5.

Probably for another post, but is Hyperstar good for fast images with EAA?
Eek! I'm visual only so no idea!
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Old 12-04-2024, 06:06 PM
By.Jove (Jove)
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Probably for another post, but is Hyperstar good for fast images with EAA?
I don't see any reason why not... at that focal ratio you won't want exposures over 30 secs anyway, and if you're using SharpCap on a laptop or ASIAir to drive the rig, use Live Stacking should be fine.
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