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L-Enhance Filter @focus3 Focus Problems

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#1 Kriz1027

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Posted 18 August 2019 - 11:33 AM

I have been struggling using the L-Enhance filter with @focus3 via TheSkyX.  I'm using a Pegasus Astro Focus Cube focuser with my SR 70mm f/5 APO quadruplet and cannot get it to focus using @focus3.  When I run the focus routine it shows numbers which indicate decent focus (2.0 - 2.5 FWHM) but when I take an image the actual FWHM value is 8 - 12 and obviously out of focus.  @focus3 adjusts the focus exposure time as it should and the routine seems to run correctly without error but never gets good focus.  I have used a bright star for focusing as well and it does the same thing...good numbers in the focus routine but bad actual focus.

 

I do not have this problem without the filter and can consistently get good focus results using @focus3 and TheSkyX with this setup, just not with the filter.

 

Any suggestions or advice would be welcome. 


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#2 elmiko

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Posted 18 August 2019 - 11:42 AM

Is this an auto focus routine? If so I can't help. I too use the same filter and a f/5.5 refractor with the Pegasus Astro Cube focuser. But I just use the included software that came with the focuser using a B- mask.

However, I will be watching this post because I am at the stage where I would like to try auto focus.

Good luck Mike



#3 Kriz1027

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Posted 18 August 2019 - 11:45 AM

Yes, @focus3 is an autofocus routine in TheSkyX and usually works well. For some reason it doesn’t like using this filter. I can manually focus using a mask but that defeats the purpose of using TheSkyX LTI to run an imaging sequence session.
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#4 tcchittyjr

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Posted 18 August 2019 - 01:07 PM

Yes, @focus3 is an autofocus routine in TheSkyX and usually works well. For some reason it doesn’t like using this filter. I can manually focus using a mask but that defeats the purpose of using TheSkyX LTI to run an imaging sequence session.

I, too, have TheSkyX and a MyT and the filter. But with the Florida Monsoon season (known as summer) I haven't had the time to try it out. Have you asked about this on the Bisque Forums?

 

TomC


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#5 elmiko

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Posted 18 August 2019 - 01:36 PM

I have noticed that the four or five times that I have used the Optolong L-eNhance filter to image the stars are really small and tight compared to without it. I'm sure it is blocking the broadband light like it was designed to do. So maybe your auto focus software is not getting a good enough signal to do a v- curve. Can you increase the exposure time in the process?

Mike



#6 Kriz1027

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Posted 18 August 2019 - 03:47 PM

Yes, I started the focus routine at 8 seconds using a 2 mag star initially and then, when focusing within the FOV of my imaging object it increased the focus exposure to 24 seconds (3x3 binning).  The results were basically the same using the bright star and the fainter star and showed sub 3 FWHM values which were obviously incorrect. Next clear night I'm going to use a focus mask first to dial in the focus then try @focus3 and see if that works better.


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#7 elmiko

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Posted 18 August 2019 - 06:44 PM

That might be a good idea. Get it close initially then the auto focus should work. You would think that it would be able to auto focus without having to do that though.

Mike




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