I really want to understand what is going on when I fiddle with f/stops, increasing depth of field, but further limiting the amount of light that hits the film or sensor. I also was having a difficult time understanding the concept of focal length considering that a lens labeled as 300mm, isn't necessarily 300mm long. Somehow, this afternoon, I stumbled across A Tedious Explanation of the f/stop. What a godsend. For issues with depth of field (which has been hitting below the belt on a lot of my pictures) and speed of the exposure (heavily impacting the clarity of my pictures), Matthew explains:
"You need to know the doubling/halving relationship and how it works with shutter speeds in exposure. This is key since the shutter speeds and f/stops you choose have implications in how your final photograph will look in ways other than purely the amount of light on the film. You need to know that as you stop down you get more depth of field. You do not need to go around calculating aperture areas for your lenses and f/stops. If you're like me, it's worth doing it once to see that it works, then forgetting about."
Thank you, Matthew, for taking the time to write down your notes. After a third read, I think I finally get what I'm doing wrong and now know how to clear up many of the problems I've had.
