My First Atik 314L Actual Image

[johnb]

Sorry about the lenght of this post

So the image below is my first processed Atik 314L image - it was supposed ot be M33 but i was a little off, but as this was more about the process I was not to concerned

Is 30 mins worth of 120 Second Exposures and associated darks, captured using ArtemisCCD, stacked in DSS and levels and curves adjusted in Photoshop

Now the questions, how do I take Flats using Artemis ?, with my cannon it was easy

I noticed that when processing in DSS it was so quick (which is a bonus), i did not do anything with the Fits options

I did try 5 min expousure but they looked really odd See http://stargazerslounge.com/topic/196539-first-light-with-an-atik-341l-eek/

Do I need to use binning at all ?

When I opended in Photoshop and then went to curves it all seemed different see the image below, normally the histogram is on the left (when using my cannon)

I think I have got a reasonable focus just need to work on the process /

Thanks in advance for advice

Regards

John B

[NickK]

Binning helps find targets and initial focusing when using "preview" mode. Once you've roughly focused, then switch to 1x1 binning, turn off preview and use a sub image to finally do fine focusing at full detail.

Flats should be straight forward - just use full resolution images (no binning, no preview) as you would do normally. Only thing is the CCD is probably more sensitive and saturates quicker. Simply aim for 1/3 -2/3 max  exposures by using short exposures. I have to use six layers of a white t-shirt with the flat panel to reduce the light so my 383L can get to 1/3rds pixel value (~22,000) without saturating.

Darks - simply build up a library of darks with the nose cap on at the set point temperature of the same length exposures. You can reuse them if you use the same temp and exposure time.. Just take normal exposures (1x1, no preview) and store them for processing later.

Nice fuzzies there - the little galaxy is showing some details already!

[Spikey]

Some of my own experiences with this chip

I used to Bin 1x1 for my luminance & lights; and 2x2 for colour (which I later changed to 1x1 just to confuse myself )

Bin 2x2 is very useful for focussing as it's generally quicker.

Darks - I never took darks, I found the noise to be so low that they were totally unnecessary and a bit of a waste of time.

Bias - always took these and subtracted them from the flats - another reason not to use darks !

Flats - I have used Artemis to take flats and as Nick states, it's a full frame shot, same binning as your lights and you want to expose for enough time to aim for an ADU value between 20-25,000. Hover your mouse over the exposure in artemis and you will see the ADU value as a changing number as you move the mouse around the image. Worth remembering that different filters will require different exposure times to match the ADU range that you need.

Your 5 minute shots with the Atik look like something is misting up somewhere; do you have sufficient dew prevention?