Image Acquisition Suggestions

[Alex McConahay]

I just downloaded the Trial, and am going to the dark sky site tonight. From what little I have had time to digest so far, PI expects slightly different inputs, and slightly different locations for the raw data than I have been used to.

I cannot find anything concise on what is the best input to work with (what images to acquire while I am at the scope). And where it is easiest to store it on the drive for later use. .....I do find bits and pieces of how I will need to use PI to calibrate and process later. But, just to be sure I have the good data to work with when I get home, my plan tonight is:

Use CCD Commander/Maxim to
1. Get as many L,R,G,B, as I can. Hopefully more than ten subs of each.
2. Grab an appropriate set of Flat frames. (I take them using automatic dawn flats in CCD Commander). Again as many as I can of each filter.
3. Acquire (using automatic dark frame acquisition in CCD Commander) at least ten dark frames at each bin, each at least longer than the longest light frame I grab during the night.
4. Get a set of at least ten "bias" frames.

I plan to put them all in one folder on the hard drive. This is the way CCDCommander usually works.

Then, when I get home, I will be prepared to use PI to its best advantage.....

Or, have I missed something?

Any other pointers?

Alex

[pfile]

i'd do 100+ bias frames if you can and many more darks. it is overkill but i'm using 180 darks. they are easy to acquire with a cooled camera, at least for 10 minute exposures. for 30 minute Ha exposures i do have fewer darks as it takes many nights to get the frames. you don't necessarily have to do the bias and darks at the exact same time. they do have some expiration date but it's probably months and not days.

so while you are out there, just do the flats and then use all of the time to collect DSO photons. do the darks and bias later.

what your subexposure length is and how long your total integration time depends on the darkness of the sky and the target in question.

[Alex McConahay]

Okay, So, I am on the rright track, but would get some out of extending the number of darks and biases......

As for length of exposure, etc.....I will do my usual check of background sky glow in a two minute exposure and then adjust to get ideal background sky glow. As long as no stars are saturating (and in my galaxy targets tonight, I don't think that will be a problem), I am good to go.

As for how to use the time, Yes, the darks and biases will be during the day while the scope is covered up and resting. None of that stuff happens at night. I'll get one object tonight, and another tomorrow, and spend the day gathering darks.

Alex

[Luigi]

Hi Alex,

I found this article to be informative:
http://pixinsight.com/tutorials/master-frames/en.html

It's a bit 'dated' in the sense that the Batch Preprocessing script's defaults are set to the suggested setting in the article (at least I think they are).

Personally, I use 16 of each calibration frame type, though I basically pulled that number out of a hat. As the article above suggests, I don't bother with darks for flat frames. I try to keep my calibration frames in a 'library' so that I can re-use them. I think they 'last' for a couple of months or so.