How often should you take another reading then? (No clouds) I mean when it just comes to the suns motion across the sky...
When you observe that the light changes... (or when you spot check your histogram).
So your saying, lets say in horse racing, I can use the same exposure settings and snap away even tho the background is changing and colors are changing?
Thats, kinda...AWESOME lol...
Maybe I will do it...
Just try it... and see how it works out but it will take practice. Only works if the general area (the entire horse track) is in uniform light. Depending on your camera (film or shooting slides), many photographers will take a single reading in this situation and purposely underexpose between 1/3rd to a full stop. As with many digital cameras, it is far easier to recover shadows than blown out highlights... a lot of the data retained by the camera's processing is in the shadows.
1) Go to an open street area where you and the general area of interest is in the same light.
2) Using your camera, take a reading off the palm of your hand. Set your camera to that setting. Perhaps underexpose by 1/3rd of a stop
3) Now just leave it there and take a few shots.
4) Walk around and take a few more.
5) Now walk into a slightly shaded area and open up a stop or two (you'll get better at estimating with practice).
6) Take a few more pictures.
7) Walk back out into the daylight and stop down a stop or two.
8) Take a few more pictures.
Now go into a cafe... have some coffee.. and check the histograms. Practice gets you closer to a "neutral" or slightly underexposed histogram consistently.
You have just learned what many street photographers have been doing for decades.
Again.. it takes practice. I've been doing it for years and still manage to bugger it up when I stop shooting and get out of practice. I would imagine a professional doing this everyday can nail each exposure in the same manner.
You master this technique and you'll be surprised just how fast you can shoot....