Artifact on images

[Blittle]

I am having an artifact show up in my images that I’m having trouble identifying the source.  It is a pretty bright star shaped diffraction like pattern coming from the right edge of the sensor.  I’ve exhausted all research into what could be causing it.  My imaging train is as follows.

Orion ED80CF > Field Flattener > ZWO 36mm filter wheel > Altair 183m pro TEC.

It becomes brighter and bigger as I increase exposure length.  I’ve attached an example.  Any help would be greatly appreciated.

[vlaiv]

That is amp glow. Nothing to worry about - proper dark calibration deals with it.

Have a look here for more details:

 

[Blittle]

2 minutes ago, vlaiv said:

That is amp glow. Nothing to worry about - proper dark calibration deals with it.

Have a look here for more details:

Should I see the amp glow when I take my DARKS?  if so, I must be doing something wrong.

[vlaiv]

Just now, Blittle said:

Should I see the amp glow when I take my DARKS?  if so, I must be doing something wrong.

Yes indeed - you'll see this but only when you stretch your darks.

Can you upload single dark fits file (you can do it as attachment in response) so we can check for amp glow?

[TerryMcK]

Definitely amp glow. You will see them in darks too. The 183 has a particularly distinct pattern. It calibrates out completely in integration.

Edited November 15, 2020 by TerryMcK

[Blittle]

Thanks for your help.  Here is one of my darks.

Calibration_300sec_1x1_0C_0009.fit

[vlaiv]

13 minutes ago, Blittle said:

Thanks for your help.  Here is one of my darks.

That dark is not for above camera. You seem to have mixed your calibration files between cameras.

This is dark from ASI071 or similar? Do you happen to have that camera as well?

Image size is 4944 x 3284, pixel size reported by SGP in fits header is 4.78µm and camera name is "ASI Camera(1)"

It also shows some glow along bottom of the frame and two places to the left:

but it is far less pronounced than that of IMX183

[Blittle]

Maybe that’s what I did.  I own that camera as well.   Thanks for your help

[vlaiv]

1 minute ago, Blittle said:

Maybe that’s what I did.  I own that camera as well.   Thanks for your help

I don't think that any software will let you calibrate with wrong image pixel count.

If you used darks in your calibration workflow, check the following:

1. You used darks of matching settings (gain, offset, exposure length)

2. You did not turn on dark optimization by accident (or on purpose)

[Blittle]

I’ll double check my workflow, and see where I may have made a mistake.

[ollypenrice]

On 15/11/2020 at 20:11, vlaiv said:

That dark is not for above camera. You seem to have mixed your calibration files between cameras.

This is dark from ASI071 or similar? Do you happen to have that camera as well?

Image size is 4944 x 3284, pixel size reported by SGP in fits header is 4.78µm and camera name is "ASI Camera(1)"

It also shows some glow along bottom of the frame and two places to the left:

but it is far less pronounced than that of IMX183

I'm impressed!!! 👏

Olly