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Electronic focuser and off axis guiding question.

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3 replies to this topic

#1 gujarbhai

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Posted 14 September 2021 - 06:57 PM

Your main camera and OAG both are in the same image path. If the focus of the main camera changes between L filter and HA filter upon filter change which most commonly happens with EAF then would it change the focus of OAG? And would that much change in focus of OAG be big enough to cause a change in guiding? Sorry if the question has been asked before.



#2 KNak

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Posted 14 September 2021 - 07:07 PM

Yes it will change the focus of the OAG, but whether that has any effect on guiding depends on how much the focus changes between your filters.  For me (Chroma B and V photometric filters), I see no degradation in guiding (I focus the imaging and guide cam using V).



#3 maudette

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Posted 14 September 2021 - 07:14 PM

Your main camera and OAG both are in the same image path. If the focus of the main camera changes between L filter and HA filter upon filter change which most commonly happens with EAF then would it change the focus of OAG? And would that much change in focus of OAG be big enough to cause a change in guiding? Sorry if the question has been asked befor

I'm so done with OAG :).  use a ONAG, One axis guider....  I've struggle for so long with OAG, just forget about it and move on :).



#4 Walter T

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Posted 14 September 2021 - 07:40 PM

Your main camera and OAG both are in the same image path. If the focus of the main camera changes between L filter and HA filter upon filter change which most commonly happens with EAF then would it change the focus of OAG? And would that much change in focus of OAG be big enough to cause a change in guiding? Sorry if the question has been asked before.

Even with my cheap ZWO LRGB+Ha filter set there is only a difference of 9 micro steps between the L and Ha filter focus positions.  Not enough to make any difference on my OAG guiding.  Just whatever filters you get try to get a set that is parfocal and you shouldn't have any issues.

 

I'm so done with OAG smile.gif.  use a ONAG, One axis guider....  I've struggle for so long with OAG, just forget about it and move on smile.gif.

Maudette, what ONAG do you use if you don't mind me asking?




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