Photo Tips – ISO/Light Sensitivity



With today being National Camera Day—let’s finish up with series of Getting To Know Your Camera.

ISO – International Standard of Organization or before digital it was known as film speed and not “in search of”.  Well, we are “in search of” more light!

Low ISO – less light and less grain or noise.

High ISO – more light and more grain or noise.


Low ISO is similar to your camera wearing sunglasses and the higher you turn up the ISO it is like you have taken your sunglasses off.  A high ISO makes your camera more sensitive to light.  It is always best to keep your ISO as low as you can so as to keep a higher quality photo.  Sometimes turning up your ISO can’t be avoided when you require a fast shutter speed.


In this photo I needed a fast shutter speed to to freeze the action and therefore I needed to turn the ISO up to 3200 to let more light in and then I could speed up the shutter release.  To refresh you from the last lesson, the shutter speed is a measurement of time and it is the amount of time that the shutter is open.  It is always better to have a sharper photo with grain rather than a unusable blurry photo.  f5.6, 1/250 sec, ISO 3200

Sometimes you change one of the settings to get the results you want, sometimes two and sometimes all three.


As you can see this photo has been under exposed – f4.5, 1/250 sec,  ISO 100 and with a few setting changes you have a correctly exposed photo.


So in this photo I wanted to capture the girls in mid air, have enough light and not be blurry.  To achieve this I kept the f-stop at 4.5, changed the shutter speed to 1/500 and pushed the ISO up to 5000.  It is very rewarding when a dark photo comes to life!


As sunlight is running out ISO is our friend at dusk.  f5, 1/125, ISO 400


To brighten this photo I kept the f-stop and the shutter speed the same, but I increased the ISO to 800.

Below are a series of photos to show how light and ISO are directly related.



ISO 200


ISO 400



ISO 400


ISO 800



ISO 800


ISO 1600



ISO 3200


ISO 6400

As you can see, the higher the ISO the photo started to become grainy, but a lower ISO creates a dark photo.  The last photo is not as bright as I would like it to be, but I didn’t adjust any other settings in the camera such as the shutter speed or f-stop to demonstrate  how just changing the ISO can change the exposure.


With a quick exposure adjustment in an editing program you can have a properly exposed photo.

Newer cameras have the capability of using a higher ISO as the quality has been highly improved in digital cameras.  If you have an older camera you may not have access to a high ISO.

Shutter speed and f-stop are the creative decisions you will make and ISO is there to help out.  That is the beauty of manual photography.  YOU now control the light in your camera!


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