Theories are best tested. Like the theory of exposure. Which, as it turns out, actually works. Let me show you.
Think: You are filling a bucket. Your aperture is like a faucet. Your shutter speed is “how long do you told the bucket under the tap”. Together, the time and the stream of water fill the bucket.
So here’s f/22 at 1/4 second. A triple of water, so filling the bucket is a slow process:
That should be equivalent to:
- f/16 at 1/8. We open the faucet, but reduce the time.
- f/11 at 1/15. We open the faucet more, but reduce the time more as well.
- f/8 at 1/30… and so on:
- f/5.6 at 1/60
- f/4 at 1/125
- f/2.8 at 1/250
- f/2 at 1/500
- f/1.4 at 1/1000
And indeed it is. Here’s f/1.4 at 1/1000:
You should be trying this stuff, not just reading this. We lean by doing. Muscle memory!
How do I know the first one is f/22? Look at the star from the lamp top right. Star means small aperture (high f-number).
Why is the other lamp green in the fast shutter picture? Because it is a fluorescent light. It goes on and off, and changes colour, 60 times a second or more. A fast shutter speed will catch that. Your shots are all going to be a different colour/brightness.
Tip: Get my books at http://learning.photography. Amazing books which will have you actually understanding your camera and what to do with it, in record time.