Clouds, clouds, and ISO

The last couple of days, we have seen some interesting weather pass through our area. Rain and thunder a couple of times yesterday, and lots of overcast skies today. Of course all these overcast skies make for just beautiful evening pictures!

Tonight, I was on my way to my photography class and had to pull off the road. It was one of those times when I was so glad I had a nice camera in the car!
 Isn't this amazing? Now I have to confess that I did shoot this one in auto... :o)
At class tonight, our instructor wanted us to shoot at a low ISO and a high ISO, but have a proper exposure which meant adjusting our aperture and shutter speed if necessary. So here is what I was able to do...
 1/8s, f20.0, iso100
 1/800s, f/6.3, iso1000
1/200, f7.1, iso640
These each took a little tweaking to get the exposure just about right, but I think I am starting to understand how all of this works. Now to keep practicing...but that is the fun part!