I admit, I googled ISO earlier to see if wikipedia could explain this better than me, and frankly, I don’t think it can. Let me take a stab at it. The lower the ISO, the less light comes in and the deeper the color saturation. The higher the ISO, the more light comes in and the more grain will appear in the photo. Here are some examples. If I am shooting in broad daylight, I keep my ISO between 100 and 200. If I come into a dark house where I do not want to use flash, I turn up my ISO to the next possible setting that will let enough light in to allow me to use a fast enough shutter speed.
This first photo was taken indoors with window light, the ISO is 500, because it was still somewhat dim inside the room.
This second photo was taken with an ISO of 200, in daylight, it was quite bright.
This final photo was taken with an ISO of 1600. It was night time, indoors, and without changing the ISO I would have had to set the shutter speed so low that they would have been blurry. You can see a slight bit of graininess in the photo because of the high ISO.
Here is an exercise; Put your camera in aperture priority mode, set the aperture to the lowest possible number. Remember, this will let the most light in, since it is opening wider. Now find a room in your house that is dimly lit, one that you would ordinarily use a flash in. Raise up your ISO and take the picture. Are you able to get the shot?
Phew!! That is so much information to take in, are any of you still with me? If you are still reading, thank you!! Ok, so now you have the information. Your assignment this week is to take two photos, one in Automatic mode, and the other either changing the aperture, changing the shutter speed or changing the ISO to make the photo different, better, then the one taken in Auto. Here are some tips:
- Do you hate that flashy look of photos indoors? Turn the flash off, lower your aperture and raise your ISO. You shouldn’t need a flash.
- Want to tell a story with your photo? Turn your aperture all the way down (lots of people refer to this as shooting wide open) and blur out some element of the photo, ie, a baby with a big sibling blurry but in the background.
- Shooting sports? Set shutter speed faster and your subject suddenly becomes sharp!
- It helps to take three or four pictures, each with different settings, so you can get a feel for how each setting will change your photo.
Do you have any questions? Be sure to post them here!