Background Streaks?

[james423896]

In one image I am getting weird streaks in the background and I am unsure where they are coming from. The attached screenshot shows the streaks getting worse with the number of frames. In the 3 frame stack the noise looks small and random, but in the 26 frame stack the streaks are terrible. They became noticeable above 10 subs.
I have tried various settings in image integration without success; I also tried DSS but this was much worse.

Is there anything I can try to stop these streaks in the background?

Thanks,

[pfile]

DSLR, right?

one solution is to dither, another is to cool the camera, another is to try decreasing the high rejection slider. another would be to try CosmeticCorrection on your calibrated (but undebayered) lights. the problem is that you've got hot pixels that are not fully removed during calibration, so they either need to be eliminated (cooling), made easier to reject during integration (dithering) or removed with CosmeticCorrection.

rob

[james423896]

Thanks for the response. It is indeed a DSLR. 

I do dither but I don't think I did between every frame. Weirdly I haven't seen this in other images, perhaps my PA was off so I got some drift in the hot pixels.

I will take a look at cosmetic correction and also lowering the high rejection setting.

I need to add more subs anyway, so hopefully these will start to cancel out this streaking.

[IanL]

Dither by at least 12 to 15 pixels between frames to avoid the pattern building up. More aggresive rejection and CC settings should help but it is easier if you don't have a constant average drift between frames.

[pfile]

cool - usually when you get those streaks it's indicative of differential flexure in the imaging train. how is your guidescope attached?

rob