Photo Tip for the Week

What is ISO and How Does it Effect Your Pictures?

ISO/Film Speed determines how sensitive the image sensor (Memory card) is to the amount of light present.

Back before digital cameras became so popular, ISO indicated film speed and you could only change the ISO in film cameras by buying different ISO rated film itself. Today though, digital cameras can adjust themselves as if you had changed the type of film you are using. All you have to do is change the ISO setting on your camera.

Your camera's sensitivity may differ a little from my camera's, but here are some general ideas of when to use which ISO speed:

ISO 50 - 80 - for taking photos in bright light; excellent for close-ups, landscape, and portraits. Produces fine detail and image quality.

ISO 100 - for extra sensitivity with little, if any, reduced image quality.

ISO 200 - cloudy and overcast days. Acceptable image quality, with very little visible noise.

ISO 400 - suitable for indoor photography whether or not a flash is used. Useful for "stop-action" and sports photographs. The quality will not be as sharp as 200, but you shouldn't have too much noise visible.

ISO 800, 1600 and above - useful for taking photos in very low light, or outside in good light when increased shutter speeds are required. It is important to know that at these ISO speeds you will have a great deal of noise/grain (tiny specks that appear in the image and reduce the sharpness/quality). There are times that noise can add to the effect of the picture; just be sure you want noise in the image before you take it...there's no removing it after you shoot.

Now, with all that said, what is the point of ISO? Well there are many uses for it, but the most common one is lighting control. The higher you have your camera's ISO set to, the easier it is to take pictures in dark places.

Taken at ISO 1600. The noise is very noticable, and the picture is lacking in sharpness.

Taken at ISO 200. There is not much noticeable noise, and the quality is sharper.

Because these photos were taken outside in the sunshine, it wasn't necessary to use ISO 1600. But when you're in darker lighting situations, and not able to use flash, it will be necessary to use a faster ISO (i.e. 800+). This can be frustrating because your images will have a good deal of noise; sometimes so much as to not have a useable image.

There are many ways to experiment with your camera settings to create great shots; ISO is one way to do that. Just play around with the different numbers in dark and light situations and see what results you get.

So to sum it up:

-If you want crystal clear, sharp looking pictures, you need to use as low of an ISO setting as you can, (as a guide, it's best to use ISO 100 as much as possible).

-EXPERIMENT and have fun!

Top photo courtesy of Bubbels.