Learning about ISO | Photography 101

January 21, 2015

After two months, it is finally time to have another lesson in photography!  Have you been working on your skills?  

There are so many different things to know and remember as you take pictures for a blog, selling online, or capturing moments with your family.  Reading a camera manual isn't much fun, so I'm taking things step by step here to help you learn and experiment in how to catch better shots with whatever type of camera you have.

Today's lesson is on ISO, which is a little easier to understand than aperture and shutter speed.  Of the three, though, it is the hardest to see a difference from.  (In case you've missed any of the previous lessons, they can all be viewed here.)


ISO is the measure of how sensitive your camera is to light.  The numbers range from 100 to 6400+ based on your camera.  The higher the number is, the more sensitive your camera will be to light.  


ISO is important when natural light is an issue.   When there is plenty of light, an ISO of 100 or 200 is perfect.  But when shooting in lower lighting, like in the morning or evening, the number can be set anywhere from 500-1000 to give the image a boost of light.  

Setting your ISO to the lowest possible number will help you get crisp, richly colored pictures.  It gives you the most preserved, natural looking colors.  You should always start with the lowest number ISO and adjust up from there.  

High ISO settings will make the photo look lighter, but can also give the pictures a more grainy quality called noise.  Bumping up the ISO value will add a brightness to your shots without adjusting other settings like aperture and shutter speed, which can change the look of your picture.


To show you what happens when changing the ISO, I shot pictures of two extreme values.  The first picture is shot on an ISO of 200 which is low and uses the natural light of the room.  If you notice in the second picture, which was shot on a high 2500, there is a slight change in the brightness of the image.  Because of the small size of the picture, this looks like the better choice between the two.  


But when looking at a close up view of the knife, you'll see that even though the high ISO picture is brighter, it is also very grainy and the colors are not as accurate as the first picture shot on 200.  Pictures shot on a high ISO start to loose their clarity.

There are times when the added light is necessary, though, which makes this adjustment important.  Photo editing software will help you to remove some of the noise in the pictures when you are forced to raise the ISO.  I'm hoping to do some lessons in editing after we've learning the basics of working with our cameras.  Does that sound good?

I hope that this lesson has given you a little insight into another adjustment you can make to bring light into your photography.  Our next Photography 101 post will be in a few weeks when we'll cover making adjustments to the exposure of your pictures.  Now, it is time to get out your camera and start practicing!  

Have a great day, and I'll see you back here tomorrow for our weekly link party!



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