what are dark/light frames

[blinky]

I have got hold of a Nikon Coolpix camera and am about to (if the clouds clear) try taking some astro pics with it. I am wondering what are dar and light frames and how do I use them? Also do I need to take dark and light frames for moon shots? Lastly the camera takes pictures in Raw or JPEG, I have heard RAW is better but why is this? and again what mode would be best for moon shots?

[moondog]

Blinky

Light frames are what you would call the normal image.

Dark frames are images taken at the same time and at the same camera setting as Light frames - same ISO, exposure time etc., but with the lens cap on the camera or the scope. This helps to improve the signal to noise ratio of the image.

RAW or JPEG - it really depends on what astro processing software you are going to use.

If you will be using the free astro stacking software - Registax, this does not accept RAW files.

But to maintain the data in the image you would be better taking the pics in RAW format and converting them ( presumimg your camera has conversion software) to 16 bit TIF files. This will preserve your data, and Registax will read a 16 Bit TIFF file.

Once stacked and played with, save your image as an 8 Bit JPEG file for posting on the SGL site.

If you have RAW format files use them for DSO's, planets and the moon.

MD