> And if the dynamic range of the camera is what it is....why cant I replicate the same results in .jpg?
Roman, think of it this way, your camera probably has a range of 0-4095 intensity shades per color channel (R,G, which get saved in a Raw file. Jpeg has 0-255, and has half the resolution for color. So Jpeg will carry less than 1/16 the information of a Raw file.
Think of dynamic range in this way. If you are taking a photo with a lot of dynamic range and getting clipping on the right of your histogram (the brights), you can always take a darker exposure to insure that there is no clipping. Meaning you get the full dynamic range of the image. The problem is that in doing so, your darks become too noisy.
So the issue of dynamic range is really an issue of noise in the dark regions of the image. Using Raw gives you more information in the darks to work with, and thus less noise and better resulting dynamic range.
NOTE, this is an over-simplification not taking into account color space of Raw vs Jpeg files and the linearity of CCD and CMOS sensors, but the point is still valid.
- Timothy Farrar : farrarfocus.com