Hi all, I have a C9.25 and photographing with direct focus with an ASI 294 there is a circular halo in the center of the image. Using the f/6.3 reducer the halo disappears. Can anyone explain to me the reason?
Circular halo in the C9,25
Started by
Giorgio Ferrari
, May 26 2023 02:26 AM
2 replies to this topic
#1
Giorgio Ferrari
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topic starter
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Sputnik
Posted 26 May 2023 - 02:26 AM
#2
RichA
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Cosmos
Posted 26 May 2023 - 02:51 AM
Hi all, I have a C9.25 and photographing with direct focus with an ASI 294 there is a circular halo in the center of the image. Using the f/6.3 reducer the halo disappears. Can anyone explain to me the reason?
Something in the camera is producing a reflection that is subdued by the reducer's addition to the light-path. Shine a flashlight onto the front of the camera, look at any ring areas that might reflect or anything on the optical window covering the sensor. Also, look into the camera adapter attached to the telescope and see if anything is reflecting back if you hit it with a flashlight.
#3
Giorgio Ferrari
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topic starter
- Posts: 43
- Joined: 21 Feb 2018
- Loc: Genova - Italy
Sputnik
Posted 26 May 2023 - 03:17 AM
Many thanks Ricco, I will try your suggestions.
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