Re: Strange Artifacts -

Wayne Hixson

That’s exactly the OAG I have too. 

On Sep 4, 2021, at 12:57 PM, Luca Marinelli <photo@...> wrote:

I had a very similar artifact from the edge of the Optec Sagitta OAG with a FLI ML16200 sensor. Moving the prism up the stalk away from the center of the sensor just a few mm took care of it. 


On Sep 4, 2021, at 3:06 PM, Wayne Hixson via <wayneh9026@...> wrote:

 Thanks Roland - I’ll bet it’s the OAG prism. I’ll take a look. 

On Sep 4, 2021, at 11:48 AM, Roland Christen via <chris1011@...> wrote:

These kind of reflections always come from some part very close to the focal plane. They cannot originate further up towards the objective lens. Since they are straight lines, they probably originate from some straight part near the chip. I have seen something similar coming from the bottom of an off-axis prism that was refracting (not reflecting) a bright star into the focal plane (similar to diffraction from a Newtonian spider). If not that, then are you using square filters by any chance?

Remove the camera body and look up into the optical train and look down into the camera. Do you see any linear (straight line) obstructions at the edges?


-----Original Message-----
From: Wayne Hixson via <wayneh9026@...>
Sent: Sat, Sep 4, 2021 1:06 pm
Subject: Re: [ap-gto] Strange Artifacts -

Hi Robert, I should have mentioned these appear on almost all the subs, so it doesn’t appear to be more random events like meteors. I suspect it’s reflections somewhere. 

Roland Christen

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