I get 8+MB files when I stitch two or more photos together. I can shoot RAW with my camera so these files are very large.

What I was trying to ask was this: when pushing the "save" in Photoshop, you then get a menu with a slide-bar that goes from 0-12 for file size. I am not clear if 12, the largest size, is the same as the input photo, or larger. I think that if you use 12, you get the same number of pixels you start with. But I really cannot be sure. MB file size is influenced by more than number of pixels in a photo. So does 12 mean no compression? On other photo processing packages there are settings that let you choose %compression. I cannot find that on my Photoshop.

You can take 100x100 pixels and then divide each for a 200 x 200 pixel photo so you can get a larger number of pixels than the original. There are algorithms that divide a single pixel based on the surrounding pixels and even trends shown several pixels away. You get more resolution, but it is artificial. These algorithms are used a lot in satallite image processing. Does Photoshop do this too?

So far my RAW files end up worse than the JPGs. Evidently I am not processing the RAW files to their optimum. I have a lot to learn with this!