DSS playing havoc with my stars

[Daniel-K]

can any one explain whats happened here this is straight out of DSS zoomed in in cs6 with no processing?

[Steve Ward]

Looks more like a focus issue rather than stacking .

Steve.

[allcart]

Looks a bit like purple fringing or halo's. What were the subs like before you stacked them.

Tiny bit out of focus maybe?

[Daniel-K]

subs are perfect focused with BYE taken with ED80 maybe it was the poor conditions

[spectre]

I've seen this if I use the 'average' mode in the stacking parameters. Try Kappa-Sigma or Median Kappa-Sigma and see if that doesn't help with the donut effect.

[Daniel-K]

i always use kappa sigma

[Spikey]

I've seen similar with excess moisture in the air. It introduces a kind of fuzziness.

Probably worth inspecting the individual subs to see if atmospherics were lousing them up as the exposures rolled in.

[Zakalwe]

Go into the stacking settings and look under Cosmetics. Untick the box that says "Detect and clean remaining hot pixels"

[Daniel-K]

Go into the stacking settings and look under Cosmetics. Untick the box that says "Detect and clean remaining hot pixels"

thants done the trick

[allcart]

Go into the stacking settings and look under Cosmetics. Untick the box that says "Detect and clean remaining hot pixels"

Good tip to remember if I ever have the same problem.

[jgs001]

The best bet for hot pixels, with a guiding setup is to introduce dithering. A small movement between subs, this has the effect that the hot pixels are no longer all in the same spot, and the kappa sigma stacking removes them. It works a treat... I know that Nebulosity and APT both integrate with PHD to control dithering, but I don't know if BYE can.

[spectre]

BYE will also do dithering with PHD.

[Steve Ward]

Is this needed using dark frames ?

I thought that was the main reason for them ?

Steve.