M51 Reprocessed - Without Darks...

[jgs001]

At the suggestion of Richie and Peter I had a go at this. I threw out the darks.... There was less noise and more info I could pull out... this puzzles me... If you look you can see there are a couple of other fuzzies in there two that were missing in the original stack with darks...

5x1200s @ ISO400

11x600s @ ISO800

10 darks

23 flats

Bias frames

Guided with a Meade DSI1C on the piggybacked Konus using PHD

Stacked in DSS (using groups)

pulled, prodded, tweaked and generally mucked about with in PS

Click the images for larger versions.

And Cropping in

[Imahumanbeing]

Excellent John, it does look less noisy. M51 has loads of detail.

Awesome picture and its nice to be able to zoom in on it!

[Psychobilly]

Sometimes you just have to try something "different"

Certainly worked with that ....

I know use "incremental" stacking....

Initially only the lights see what it looks like, then if it looks like it needs flats and I have them I re-stack with them sometimes use some "clean" library flats which are dust mote free to tackle vignetting , then another look and see if it needs bias... this only works for the 1000D (so should for the 450) the 350D definitely needs darks and bias...

Peter....

[Aza]

Very interesting, I might have to give this a try.

Check this thread on Cloudy Nights, also very interesting, and your M51 target would be a perfect test:

Telescope Reviews: Erasing DSLR Noise

(I am unsure of the rules to linking to another forum, so MODS please remove if I shouldnt have done it!!)

[jgs001]

Thanks guys.

I've tried that very thing Peter with my NGC4088 image from last night, although I did it the other way around... The long way to get there...

Interesting article Arran. I wasn't intending to go back to M51 for now... I'm thinking I'll add some guided data to my Leo Triplet, I think I'll give that a try.