NGC6888 Jellyfish/Brain false colour HaO3 & Inverted Ha 75% actual size

[Rocket Pooch]

[Fay]

Very nice Chris. Do you mean The Crescent?
Have you rung Ian King yet?

[Rocket Pooch]

ok we made up a name for it.

yes i did call him he was very halpfull as usual, hence the results

[Fay]

Having looked up the Jellyfish, it reminded me that it is one I meant to do, it is so complex also I like it in mono.
Have to wait for it to come around again.

[MarkS]

Having looked up the Jellyfish, it reminded me that it is one I meant to do ...

I looked up Jellyfish in Microsoft's Worldwide Telescope but it didn't find it ...

[Fay]

Gemini

[Mike]

It's the Crescent Nebula.

[Rocket Pooch]

I made it up!!!!!  I think it looks like the cauliflower nebula...

[Rocket Pooch]

Update, got notification from Atik the cooling was off on this image due to a bug in the AA Driver, so this image was not cooled!

[Fay]

Thank God for that, Chris. Waiting to see the next image now!!!!!!!

[Rocket Pooch]

I have now got the test images from one of the guys who wrote the Artemis capture software, he has no hot pixels unlike me, so I now need to cause hell.

Pissed of from Mottingham...

[Fay]

So, Chris, are you saying that your images will not improve when the cooler is put on?
So, that was not the problem?

[Mike]

Hot pixels mean those pixels are dead and appear permanently white on your image no matter what you do. The higher the quality of CCD the lower the number of hot pixels. Ideally you want none, though 'drizzling' inbetween frames (i.e. having the mount shuffle the image around a few pixels) will mean that you can average them out using a Sigma stack as each sub will have the hot pixel in a different part of the frame relative to your image so that after alignment they will not be in the same location as previous frames.

[JohnP]

I understand that Mike but out of interest I took some 5min & 10min darks with my atik 16ic camera. There are quite a few hot pixels but they are only at the 1000-2000 ADU level not 65000 so when I stack & process my images they just disappear into the background/ signal. That is why I don't need to take darks. I'm wondering if I turned my cooler off would those hot pixels go to the 65000 level????

John

[Mike]

I don't think it would make any difference. I think a dead pixel gives out a set signal.

[Rocket Pooch]

Hi,

Fay yes with the cooling on the camera will be a lot better, I have already measure the noise and its down by over 50%, this will mean the camera will be more sensitive.  The only issue I have is the hot pixels, I can process them out, but I really did not want to take too many darks, but I've allways done it so I suppose there's no change there.

Mike, the issue with the dizzle etc it that it assumes your image drifts about, normally mine does not with the ED80 and EQ6, the image scale here is probably 3-4 arc sec per pixel and the guiding on the last 8 frames was within 1 pixel of the camera so all the images we're bang on top of each other.  But the Sigma combine does clip the nasty pixels.

Anyway, if I can get a better one I will, but lets see.

John, the camera you have is the best one ATIK have made and they know it, the chip is excellent and the Ha is up in the 68-70% well about even the 314L, my dark noise is not 200 whats yours, I think they are about the same now?  Oh yes and you are right the case gets hot!!!

Anyway, when its clear for a couple of nights I'll get a decent image up to compete with Rob and Mark

Ta


Chris


P.S.
http://farm4.static.flickr.com/3099/2573531076_f0dab20467_o.jpg

[Fay]

Your image looks superb on Flickr, Chris!