Changing the f number or not.

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denababy
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Changing the f number or not.

Post by denababy » Thu Aug 23, 2018 10:04 am

Hi me again asking for advice. I have an Explore Scientific ed80 triplet which is, I believe f/6, and also a Daystar Quark which I think works well or better between f4 and f8. I am still playing with spacers Etc. as well as different cameras to get the best views I can. Been cloudy for days here in Leicester so not enough blue sky to allow me time for experimentation. Will anything I add on change the f number? Any one help please.

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krakatoa1883
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Re: Changing the f number or not.

Post by krakatoa1883 » Thu Aug 23, 2018 3:32 pm

If you have the Chromosphere version it should work fine @f/6, although the higher the native f/ of the scope the better the final results one can obtain.
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Randy Shivak
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Re: Changing the f number or not.

Post by Randy Shivak » Thu Aug 30, 2018 2:12 pm

The Quark already has a 4.25x telecentric lens so operating at above F8 would be a bit much. Your F6 will work great.

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MalVeauX
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Re: Changing the f number or not.

Post by MalVeauX » Thu Aug 30, 2018 2:22 pm

denababy wrote:
Thu Aug 23, 2018 10:04 am
Hi me again asking for advice. I have an Explore Scientific ed80 triplet which is, I believe f/6, and also a Daystar Quark which I think works well or better between f4 and f8. I am still playing with spacers Etc. as well as different cameras to get the best views I can. Been cloudy for days here in Leicester so not enough blue sky to allow me time for experimentation. Will anything I add on change the f number? Any one help please.
The Quark is ideal with an F30 light cone.

F6 x 4.3 (internal telecentric) is F25.8. Close. It would be better at F7. That would be a 68.5mm aperture.

But, you also need to match your pixel size for sampling to that focal-ratio. And in turbulent skies, undersampling is better than oversampling. So you're best bet is to likely stay F6 and not worry about it and use the biggest pixels you have to match that F25+ light cone.

Very best,

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Valery
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Re: Changing the f number or not.

Post by Valery » Wed Sep 05, 2018 1:53 am

better to change the F/N for a slower one.
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