ok, so i think i know the basics of creating an hdr image from different shots at different exposures on my computer, but while I was looking at a tutorial to actually shoot the images, it said to do bracketing at exposures of -2, 0, +2, but I have no clue how to do that. I know it has something to do with the exposure, but I just dont know how to adjust the exposre to be -2, 0, and +2. does say for example -2 mean i shoot the scene 2 stops down? which would mean decreasing the f number right? i dont really know, as i am still very much a noob.