Light Leak Ring Fix

James Wu

Hi,

I’ve been using a GSO RC 10 and ran into an issue. After completing the integration of my images, there’s a visible bright ring around the edges, which I suspect is caused by a light leak due to the baffle tube being too short.

I’ve tried flat-field calibration and GradientCorrection, but it doesn’t seem to correct the issue. Are there any feasible processes to deal with it?

Would really appreciate your advice!

James

BlockHead

I don't think this is a light leak per se... it might be scattered light caused by the baffle (or an adapter). I would work on finding the source.

Unfortunately, in my opinion, there aren't great solutions for getting rid of this. You can force Gradient Correction, DBE and others to be very aggressive and minimize this... but it will not entirely go away. 

If you had *some* exposures that did not show this artifact...then you have some leverage. But with the artifact in every exposure it is pretty much baked in.

In a few videos I do demonstrate how to remove structure using HDRMT. You can do this... you would need to create a starless image, Then you would have to mask every galaxy. Finally you apply and the ring will be removed. It is not a great solution. I demonstrate this technique a few times in CometAcademy.

-the Blockhead

James Wu

Hi Adam,

Thank you for your detailed explanation and guidance! I’ve managed to identify the root cause of the issue. Based on "", it seems that the GSO design flaw allows light to directly hit the sensor without reflection. I believe the ring artifact occurred when capturing flat-field images, as light directly entered the sensor.

I tested images without calibrating the flat field, and after applying Gradient Correction, the ring artifact was no longer visible. I’ve also ordered a new baffle from the manufacturer and hope it will resolve the problem.

One last thing: do you have any recommended workflows to compensate for the absence of flat-field calibration?

Thanks again for your help!

James

BlockHead

No. Applying flats is supposed to always help. I do not have workflows where you do not do helpful things. :)

-the Blockhead