I've done some experimenting with using the "raw" image format for astro photos. The Nikon Coolpix 4500 camera doesn't officially have a raw mode, but it has a diagnostic mode that produces raw images, and can be turned on or off using the cpixraw computer program.
The first problem I ran into is that the "Nikon Transfer" program won't copy raw files from camera to computer, but (with the camera in USB "Mass Storage" mode) it's easy to use Windows explorer to copy the files. Having copied the files it's then necessary to convert them from Nikon's proprietary raw format to something a bit more standard. I use the raw2nef program, by the author of cpixraw. Lastly, I convert the NEF files to FITS using Dave Coffin's dcraw program and the netpbm tools.
To simplify all this file copying and conversion, I've written a simple Python script to do it all with one mouse click. Please feel free to download my program and modify it to suit your own requirements. Don't worry if you don't know Python; it really is one of the easiest to learn computer languages I'm aware of. To use my script you need to install the following:
Before running photo_transfer.py you will need to edit it using any text editor, e.g. WordPad. At the start of the script are a few lines that set paths for your photo storage area and the location of the programs the script uses. Also, if you are using a Coolpix camera other than the 4500, you may need to change the raw image size.
When photo_transfer.py is run it does the following:
NEF images can also be converted to Photoshop, by uncommenting the appropriate lines.