Forgot i tried some 600s subs...Gamma Cyg...

[Psychobilly]

Here's one of the 600s ISO800 subs from lastnight ...no darks, no flats no bias...just a quick tweak - Just autoguided no drift alignment of the pier...

(click to enlarge)

And heres the satck of 2x600s with darks and bias before processing...

(click to enlarge)

Might have to start using 450 or 600s subs

Billy...

[cygnusx1]

Billy nice shots, perhaps try gradient exterminator to lose some of that discolouration.

[jgs001]

Wow Billy, that's come out great, and what a difference 2 subs and flats and darks make...

[Psychobilly]

Wow Billy, that's come out great, and what a difference 2 subs and flats and darks make...

Hi John,

No flats thats the problem - hence the vignetting...

These subs were only really to check noise levels and treacking accuracy to see if i can extend the duration of my sub a bit further...so havent really processed the images.

Billy...

Had to have a play with it though ....

(click to enlarge)

[jgs001]

oops muddling flats and bias frames.... :scratch:

[narrowbandpaul]

i too have messed around with bias frames...

camera manufacturers add what is called an offset, or bias, to prevent negative intensities from appearing during dark subtraction. For a low noise chip, this bias is greater than the dark signal, even after 30mins.

Just shows....defo do biases

Great image btw, billy.

You certianly can do those longer subs....

[Psychobilly]

Thanks Paul,

I think I am going to settle on 450s subs at ISO800 as there is no visible glow on the sensor at that setting its nice to know I could probably go longer from a tracking point of view incase I ever get into Narrowband imaging... wonder how the moded 350d will perform ?

Hoping that the forecast is a bit wrong for the weekend as it could be "Nebula Frenzy II" got the target list after last weekends effort just need to get the subs in now

Billy...

[narrowbandpaul]

i think the modded camera would perform fine, for narrowband. I havent seen modded slr's doing anything more than Ha. Perhaps you could be a pioneer!