Double image in reflector telescope

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  • Thread starter kolleamm
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  • #1
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Main Question or Discussion Point

Complete reflector novice here. Just got a reflector (using refractor before). I had no problems doing astrophotography with my refractor however with the reflector I get double images.

Why is this so? Is this a collmination problem? It's not the camera because there's double images when I look through myself.

Thanks in advance
 

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  • #2
Borg
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Just a guess but, it looks like you're trying to focus on something that is too close to your telescope. How far away is the object and what is the focal length of the telescope?
 
  • #3
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It has a 1400mm focal length. Here is also a picture of the Moon which appears to have the same problem. The tree is just across a small parking lot.
 

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  • #4
Borg
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  • #5
russ_watters
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Borg is correct.

The moon definitely doesn't have the same problem. It may not be quite perfectly in focus, but it is close.
 
  • #6
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Is it possible I have a bad quality mirror? My refractor had half the aperture and gave me way better detail. Although yeah it could be the alignment.
 
  • #7
russ_watters
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Is it possible I have a bad quality mirror? My refractor had half the aperture and gave me way better detail. Although yeah it could be the alignment.
Based on the pictures you posted, I find it very unlikely that you have a bad quality mirror. But you may want to look into a "star test collimation".
 
  • #8
Borg
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My refractor had half the aperture and gave me way better detail.
Here's a link on collimation of the telescope with some good graphics.
Have you ever wondered why your reflecting telescope didn’t perform as well as a refractor of even half the aperture? Do you think that perhaps the main mirror in your telescope doesn’t quite measure up to others of equal size that you’ve looked through? Do you always seem to be blaming the seeing conditions for poor images even when someone right next to you thinks the seeing is pretty good? Chances are that the only thing wrong with your reflecting telescope is that it needs to be collimated.
 
  • #9
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Thanks guys, I'm gonna change the cam first too and see if that helps. I was using my iphone (8 MP) but this cam is only 3MP, so I'm gonna print out a support and see what happens, and align the mirrors too.
 
  • #10
russ_watters
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Does it look better with your eye? I wouldn't trust an iPhone with this task. FYI, none of the pictures on my website were taken at more than 2mp.
 
  • #11
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Does it look better with your eye? I wouldn't trust an iPhone with this task. FYI, none of the pictures on my website were taken at more than 2mp.
Wow your images are very impressive! Especially being able to see some color on Europa.
 
  • #12
russ_watters
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Wow your images are very impressive! Especially being able to see some color on Europa.
Thanks! My recommendation if you're on a budget is to get a decent webcam, remove the lens and attach it without an eyepiece to the end of the telescope. That's called "prime focus photography". Then take uncompressed videos and use stacking software like Registax (free) to process it. That's how you get the ultra-clear photos of the moon and defeat atmospheric distortion.
 
  • #13
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Thanks! My recommendation if you're on a budget is to get a decent webcam, remove the lens and attach it without an eyepiece to the end of the telescope. That's called "prime focus photography". Then take uncompressed videos and use stacking software like Registax (free) to process it. That's how you get the ultra-clear photos of the moon and defeat atmospheric distortion.
Sweet. I managed to hopefully fix the double image problem by just focusing the telescope right. I took off the lens on the cam that came with the telescope and attached it to a 10mm eyepiece, the magnification looks way better.

Would you have any advice on how to set up tracking for a GPS telescope. I haven't found any good tutorials. I did the Moon alignment test and it didn't work. I see a sign on my telescope that says south, so am I supposed to point the telescope south before the test? Thanks in advance!
 
  • #14
russ_watters
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All telescopes are different: what is the make/model?
 

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