Does anyone know what causes this?

Radian 61 Artifacts Help Needed
3 replies•216 views
Sergio Moya Lara avatar
Sergio Moya Lara avatar
While I was checking a photo I took a few months ago, I noticed this strange pattern in this star... Is this caused by some kind of aberration?  It does not worry me at all, just for curiosity

Equipment: Radian AP 61/275 Raptor OTA + ZWO ASI 533 MC PRO + UV/IR Filter


andrea tasselli avatar
andrea tasselli avatar
Nothing to worry about, something quite small protuding in the light path, in or before the entrance pupil.
Marc avatar
Marc avatar
I suggest you read this: http://interferometrie.blogspot.com/2014/08/esprit-tuning-how-we-finetune-esprit80.html

Basically, depending on the exact design of the lense assembly, there are typically small obstructions at the edge of the assembly that can cause such patterns. For example, individual lenses can be separated by rubber bands, wrapped into a ring. If these do not snuggly meet at the ends, you get the sort of issue you see. 

It's fairly normal - although less common with more high end instruments.
Helpful
Sergio Moya Lara avatar
Sergio Moya Lara avatar
Marc:
I suggest you read this: http://interferometrie.blogspot.com/2014/08/esprit-tuning-how-we-finetune-esprit80.html

Basically, depending on the exact design of the lense assembly, there are typically small obstructions at the edge of the assembly that can cause such patterns. For example, individual lenses can be separated by rubber bands, wrapped into a ring. If these do not snuggly meet at the ends, you get the sort of issue you see. 

It's fairly normal - although less common with more high end instruments.

*** Thank you! I will check it out ***
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