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Celestron C90 Registry

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157 replies to this topic

#151 dannyleo

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Posted 26 December 2020 - 08:50 PM

THANKS ANM!  Appreciate your quick help.



#152 RSX11M+

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Posted 10 January 2021 - 03:39 AM

Thank you for your submission.
 
dannyleo - I have seen C90s with baffle issues repaired, some are chronicled in CN forums. The disconnected secondary baffle in your images (that's what it appears to be) can be re-attached. You need to get advice on the type of glue. Be sure to avoid Cyanoacrylate (aka: "crazy glue")  as they will give off vapors while curing which damage optics and mirrors.

I agree with ANM that the most likely cause of the damage to the primary baffle would be solar induced, though I've not personally seen that before.

 

I cannot imagine getting help from Celestron on this, but it's always worth a call to get advice.

 

These are not too difficult to disassemble, clean and put together, so don't be discouraged. 

 

The new Registry with these additions is offered in JPG and PDF.
 



#153 SkiWhiz72

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Posted 28 January 2021 - 08:48 PM

Hello I have two C 90

 

Orange spotter #910866 optic #347 gold band 5x24 finder

 

Orange spotter #97357 optic#4424 gold band



#154 dannyleo

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Posted 01 February 2021 - 10:19 AM

Thanks SkiWhiz72.  SpaceNut59 already answered and I bought his.  Appreciate it.



#155 Ps191

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Posted 01 February 2021 - 09:41 PM

Can anyone help me understand what can be learned from this c90 registry?
I've looked over the data and there seems to be no rhyme or reason to its order. What does it tell us and how do we interpret its data?

Thanks,

#156 RSX11M+

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Posted 02 February 2021 - 12:09 AM

Can anyone help me understand what can be learned from this c90 registry?
I've looked over the data and there seems to be no rhyme or reason to its order. What does it tell us and how do we interpret its data?

Thanks,


Well, let's see... We can't know what patterns might emerge until we've collected the data, but judging by a more complete Registry like that for the C8, we learned a lot.

The most common thing we are asked is "When was my particular scope manufactured?", and the only data an owner can provide is the Serial Number. With a C8, the SN can now be used to determine the date of manufacture to a very precise degree. With the C90s, we only have a general idea at this point.

We eventually expect to be able to make a good guess as to when production features changed. When orange tubes were dropped in favor of Black. When the F5.6 versions were made.

There doesn't seem to be much correspondence among optics numbers as yet, but it may be possible to glean something from these as well, once enough data is amassed.

Those of us with F11 and F5.6 models have noticed some mechanical differences in the corrector mounts and in baffle tube parameters. Understanding these differences may eventually lead to a deeper understanding of optical artifacts of different vintages and how to cure them and what performance characteristics usually suffer.

Collected data often helps those who would like to work on, restore or repair their scopes gain more pre-knowledge on what they are about to undertake.

 

Beyond that - it's just plain fun. cool.gif


Edited by RSX11M+, 02 February 2021 - 12:19 AM.

  • Kasmos and Stevegeo like this

#157 dannyleo

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Posted 02 February 2021 - 10:14 AM

Wow.  I didn't know they made an f5.6!  That sure seems like quite an improvement over my f11.  Correct me if I'm wrong, but that's twice as fast and therefore I can shoot at twice the shutter speed for shooting range work, or get double the exposure for night work.  Isn't that a win-win all around?  



#158 RSX11M+

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Posted 02 February 2021 - 11:30 AM

dannyleo - Yes, the F5.6 is faster and has a wider FOV. For photography, it has a mixed bag of aberrations, so it's not the best telephoto lens for most applications. (the smaller your image circle the better) However with a controlled situation, it's benefits can be exploited.

 

I myself became interested after seeing C90 F5.6 registry entries, and managed to get one in decent condition. So the registry served me - as one example. Hopefully others will find the C90, C5 and C8 registry information beneficial for their purposes.

 

It's difficult to know how "information" such as the registries provide will be useful. I had to think in order to answer Ps191's inquiry,  because what's possible changes as information accumulates.  Each member has their own desires and may see implications we don't recognize - we hope they will share.

 

One aspect that's come up, with the C8 in particular, is the desire to morph one of the datums into an ownership attribution. This hasn't been fully adopted, but there is value to members that might want to know "provenance" of a particular instrument's collectibility or in case of theft. The registry isn't yet well suited to these uses but the idea has come up and been accommodated to some degree. 

 

Understanding of the C8's evolution has provided so much detail that we can offer a particular scope's production date range based solely on characteristics. (without Serial Number) -Something that would have been impossible with commonly available information.

 

However, the moderators don't like us to stray too far from a threads's topic, so delving deeply into a particular aspect of a model or it's performance imperils that rule. Should such an interchange be desirable it can take place in one of the other suitable forums. I will entertain such here, if it is candidate for addition to a Registry's information, or just in answer to a quick question.

 

You can always shoot me a private message if in doubt as to a subject's suitability.




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