The Basics #3: Understanding ISO

We talked about Aperture, and Shutter Speed and now it's ISO's turn.  ISO is another way to get more light when exposing your photo.  Light comes through your aperture and passes the open shutter onto your sensor.  By turning up your ISO its telling the sensor to become more sensitive to the light coming in.  Watch what changing your ISO can do.

My Settings were Shutter 1/80, F 2.8.  It was dark.















I know of some photographers who won't go past 640.  Then I know others who'll go all the way up to 6400.  The reason for this is because the higher your ISO is, the more grainy your picture will be.  Choosing to go as high as 6400 all depends on how you feel.  I've personally gone as high as 6400 for a wedding, embracing the 'texture.'  Here are two example photos.  The top one I actually went into photoshop and smoothed her skin and the second you can see the graininess.

Hope that helps you understand ISO if you didn't know.  We have a great range of followers from little experience to advanced and Go{4}Pro really wants to help those who need more understanding figure these things out.  It can be really difficult to learn on your own and we want this blog to be a safe place for any photographer no matter where you may stand.  We truly love our readers and want everyone to succeed with their dream!


  1. I love your blog- you guys are awesome!! I have a question I could use some help with if you wouldn't mind! Does window light change much with the weather? Like on an over cast day, is the window light really that different? How about when you are getting direct sunlight into the window, but place your subject just outside of that direct light? Do those two situations make the window light that different from indirect window light on a bright sunny day? I'm just trying to figure out why my pictures by the same window turn out spectacular some days and blah other days. Thanks!!

  2. You are amazing, the way you used the graininess in the second photo to enhance the mood of the picture. Smart photographer you are!

  3. Happy we're so glad you like our blog! :)

    To answer your question window light is just like outside light. If the sun is bright outside shining through your window it'll be bright and harsh inside. If it's overcast outside, which we love, it'll be nice inside. You do have to remember that the window itself is a diffuser too and even though our eyes may see the subjects with good light, the camera will probably see things darker. That's when you turn up your ISO. AND the closer your subject is to the window the brighter the light is going to be so if it's bright outside maybe pulling your subject away from the window is best. The two best things for window light is 1. A window that faces north because the sun goes E -W and 2. An overcast day to get that nice soft even lighting. I hope that answers your question! Maybe I'll do a post on it!

  4. i love grain but not on faces but sometimes it is cool. i'm not afraid of 6400 ISO - bring it! you guys rock!