To add or not to add collimation for SCT in SC?

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RickBG
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To add or not to add collimation for SCT in SC?

Post by RickBG »

Hi Robin,

I had once asked you that question in the past and considering now that you are devoting full time to SC, I'm hoping your answer would be "perhaps in the future" or "I'm thinking about it". I like to see SC as an all inclusive program where we do not have to resort to another esp. for collimation for SCT's such as "MetaGuide" application. I mention this program because it can give you some ideas on how to approach it. As we all know, having good collimation like having good focus is paramount in astrophotography. Otherwise I'm very happy with SC and its many innovations...Job Well Done! :)

Rick
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admin
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Re: To add or not to add collimation for SCT in SC?

Post by admin »

Hi Rick,

any more collimation functionality is unlikely at the moment - I added the Newtonian collimation experiment when I had a 10" f/5 Newt on loan, but gave it back in the end - I found it too high maintenance. I also have an SCT, but it hasn't seen the light of day (or night) in 2 or 3 years, partly for being fickle and partly because getting the tube currents to stop seems basically impossible. Currently my approach to collimation is 'image with refractors - then it's not something you have to worry about!'

If the SCT comes out of the box at some point in the future then maybe my view on this will change - I have a theory that actually you should *heat* the upper surface of an SCT (with dew heaters or similar) to keep the top of the tube warmer than the bottom and therefore still the tube currents. One day I will get around to trying it out :)

cheers,

Robin
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Menno555
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Re: To add or not to add collimation for SCT in SC?

Post by Menno555 »

admin wrote: Mon Apr 05, 2021 1:30 pm ...

If the SCT comes out of the box at some point in the future then maybe my view on this will change - I have a theory that actually you should *heat* the upper surface of an SCT (with dew heaters or similar) to keep the top of the tube warmer than the bottom and therefore still the tube currents. One day I will get around to trying it out :)

cheers,

Robin
I think your theory can hold some merit. I have the Meade LX200 8" ACF SCT and since that I have my dew heater, I feel it all is a bit better. On normal nights with no to low change on dew, I set it to around 20% capacity as standard right from the beginning. So it's part of the cooling down of the SCT too. But I have no data for it, it's more like it feels logical to me :)

Menno
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