Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Refractor alignment maybe

  • Please log in to reply
2 replies to this topic

#1 thekubiaks

thekubiaks

    Vostok 1

  • *****
  • topic starter
  • Posts: 147
  • Joined: 16 Dec 2019

Posted 14 January 2020 - 12:05 AM

I have the ES ED127 F7.5 refractor.  I'm trying to figure out if my focuser is out of alignment.   I used a Cheshire and know my optics are perfectly collimated.  My images are very sharp corner to corner.  I checked CCD Inspector and the interesting thing is, I have an ES Focal reducer Field Flattener.   CCD Inspector shows a 34 degree curve in the image but no tilt.   I thought a field flattener takes out this curve?   Anyway, my images look sharp so I'm not complaining.   But, looking at this image of my Master flat, the circles are not centered, I cant figure that out.   I put a laser collimator and the dot on the wall didn't move when I rotated it??   So, why the offset circles??  Any ideas, thx.

 

**NOTE The checkered pattern in the image is just a png to tif conversion issue, not present in the Master Flat

Attached Thumbnails

  • Focuser alignment.jpg


#2 Lonkero

Lonkero

    Lift Off

  • -----
  • Posts: 23
  • Joined: 06 Jun 2019

Posted 14 January 2020 - 12:18 PM

Is the backfocus right with the reducer? Or then there is tiny amount of sensor tilt

#3 thekubiaks

thekubiaks

    Vostok 1

  • *****
  • topic starter
  • Posts: 147
  • Joined: 16 Dec 2019

Posted 14 January 2020 - 12:51 PM

Thank you for the response, let me ask you this, if I had the backfocus for the focal reducer incorrect, wouldn't I be out of focus? So the strange thing is Explore Scientific told me I need both 37mm extensions to get focus with that reducer but I found that I got focus at only 45mm. Interesting?? thoughts?


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics