Dust bunnies arrrgh

[CedricTheBrave]

My stacking process does not appear to get rid of these

am I asking too much?

see below image rough process just to show the issue and a jpg of one of the flats that shows the dust bunnies (at least thats what I think they are)

20 x lights

10 x darks

20 x flats

is it possible the flats are rotating 90 degs as if I open one of the raw images in Affinity it opens in portrait but the lights and darks are landscape! as its done here !!!

 

Edited January 7, 2021 by CedricTheBrave

[wimvb]

On 07/01/2021 at 19:19, CedricTheBrave said:

is it possible the flats are rotating 90 degs as if I open one of the raw images in Affinity it opens in portrait but the lights and darks are landscape! as its done here !!!

Very unlikely. The image rotation information is not used by the calibration software, only by image viewers. To see if flats work, you calibrate one flat sub with the master flat. The result should be a fully corrected and uniform, mid gray image. For osc, there may be a colour bias.

[newbie alert]

Under correcting so you need to exposure longer on your flats.. what adu are you aiming for, or what's the histogram look like?

[CedricTheBrave]

6 hours ago, wimvb said:

Very unlikely. The image rotation information is not used by the calibration software, only by image viewers. To see if flats work, you calibrate one flat sub with the master flat. The result should be a fully corrected and uniform, mid gray image. For osc, there may be a colour bias.

thanks for this

see image of one flat calibrated against the master flat so it looks like its not working, you can see the bunnies also the vignetting is obvious

screenshot of dss 

 

 

Edited January 9, 2021 by CedricTheBrave

[wimvb]

As @newbie alert already noted, if your flats are not working, you need to check if they have a correct exposure. Flats should be mid gray, and the histogram should be in the middle of the display on the camera (assuming you use a dslr). Before you apply flats in your calibration process, they themselves must be calibrated. This is usually done with bias exposures. If you haven't done so already, add bias frames to the calibration and stacking.

[CedricTheBrave]

5 hours ago, wimvb said:

As @newbie alert already noted, if your flats are not working, you need to check if they have a correct exposure. Flats should be mid gray, and the histogram should be in the middle of the display on the camera (assuming you use a dslr). Before you apply flats in your calibration process, they themselves must be calibrated. This is usually done with bias exposures. If you haven't done so already, add bias frames to the calibration and stacking.

ok i get you i will redo my flats looking at the histogram, everyday is a school day cheers

[CedricTheBrave]

maybe not grey because its a modified dslr?

[wimvb]

35 minutes ago, CedricTheBrave said:

maybe not grey because its a modified dslr?

As close to neutral as possible without "bending over backwards"