ISO is going to be the end of me...

What is ISO you may ask?  Well unofficially, it is a thorn in my side.  Officially, it is the sensitivity of your image sensor.  Early on my road to understanding the technical side of photography, I left the ISO on the "auto" setting because it was one more thing I just didn't understand.  I figured if I left it on auto, the camera would do what was best... I couldn't have been more wrong.  If you are shooting on a bright and sunny day, your ISO will be at 100 or 200.  If you are shooting indoors (without a tripod) or the light is very dim, your ISO will be much much higher.  My camera has ISO settings of 100, 200, 400, 800, 1600, 3200, and 6400.  You want to keep your ISO as low as possible or your photo will start having what we call "noise."  Basically it looks like grain on your photo.  If you are using a tripod, even in darkest lighting situations, you can keep your ISO low.  What will happen ~ is your shutter speed will be slow... but since it is on a tripod, your image will still come out crisp.

On my first nighttime photography photoshoot, ISO got the better of me.  I left the ISO setting on "auto" and since it was so dark, the camera "decided" to set the ISO to 3200.  This action basically rendered all my photos pretty useless for anything except my personal collection.  Here is an example.

ISO 3200 ~ 28mm ~ f/3.5 ~ 1/30 sec

© Corrie M Avila

I overexposed the above photo so that you can see the grain better.  Click on the photo so it opens larger and look at the sky.  It's really bad.  There are some options in Lightroom and Photoshop to address grain in a photo ~ however when it is this bad... there is really no way to fix it.  The only solution is to cart all your equipment back out and redo the shoot.

ISO 200 ~ 60mm ~ f/7.1 ~ 1.6 sec

© Corrie M Avila

When you click on the second photo, you will see that there is no grain.  The black is truly black without the "noise."  My ISO is set to 200 and my shutter speed is much much slower, but since I was using a tripod, the photo is crisp.

I no longer keep my ISO in the auto setting.  I have it set to 100 and then if I need to change it, I know that I am doing it.  I try to keep my ISO on 100 or 200, but will go to 400 if necessary.  Anything higher than that will cause noise. 

Oh, and one more thing.  I read somewhere that it is a good idea to have a series of settings on your camera that is your "baseline."  No matter what you are shooting, you always put it back to this when you are done so that you aren't caught unaware when you grab your camera to do something else.  This is something I have started to do and recommend you doing it as well.  My baseline settings are that I have my ISO on 100, my camera mode on "M" for manual, my focus on autofocus, and my timer/remote OFF.  This makes it so much easier when I am running through the house for my camera because I see the bald eagles back out on their perch.  I don't have to waste the time changing my settings, my camera is ready to go!

Here are a few links that help explain ISO a little further

• http://digital-photography-school.com/iso-settings
• http://www.slrphotographyguide.com/camera/settings/iso.shtml

Hope this helps explain the elusive ISO!

Happy Shooting

Corrie <3