Friday, January 27, 2012

Rosette Nebula

Rosette Nebula by edhiker
Rosette Nebula, a photo by edhiker on Flickr.

What I didn't do -
To use BPM, need to do:
How to make a BIAS frame
Note: If you use a Bias frame you must first pre-process your dark frames by applying the MASTER BIAS frame to it, making the dark frames, a “clean” dark frame, using this cleaned dark frame when you pre-process your light frames. The uncleaned dark frame has the bias signal in it as well. If you do not do this, during pre-processing you will not remove the bias component. Don’t worry; I have instructions on what to do.
1. Cover the scope and take as many Bias frames as you did DARKFRAMES. Use the shortest duration time allowed by the software. Don’t get the BIASDARK confused with your DARKFRAMES. If you took 10 DARKFRAMES then you want to take 10 BIAS frames at 1ms.
2. Now, combine your Bias frames together and label it master bias.
3. Now, you must apply your MASTER BIAS frame to each individual DARK frame. Use the same method as though you were applying the dark frame to your light frames. Refer to STEP 2 ‘How to process images’. Combine the master BIAS frame to each DARK frame. When you use the process in step 2 you will select only bias then click done. Once you have done that, instead of selecting light frames like the window says you will simply select your dark frames. The DARK frames should now be labeled with PPRC attached to it. To keep it in simple terms, if you labeled your DARK frames as CRABDARK. They will now read “pproc_CRABDARK”
4. Now that the MASTER BIAS frame has been removed from the Dark frames, you need to stack the DARK frames that are labeled pproc. Once the dark frames have been combined, label the dark frames ‘FINALDARK’ or whatever you want, just as long as you know that the final bias process has been been completed. The ‘FINALDARK’ frame is what you will use in Neb to process in your light frames. When you process your frames the ‘FINALDARK ' will be used as your ‘MASTERDARK’ frame.
Tip. You can take your bias frames the same time you take your dark frames.