Thank you for coming back to read about the next crucial part to learning how to use your DSLR! Today I am going to talk about  ISO. The second principle in photography!

ISO measures your camera sensor's sensitivity to light. When your ISO number is lower, the less sensitive your camera is to the light. The more you increase your ISO number the more sensitive to the light it will be. The same principles apply as in film photography – the lower the number the less sensitive your camera is to light and the finer the grain.

When you're outside on a sunny day taking photos, your ISO will most likely be at 100. However for darker environments, and poor light conditions, you would increase your ISO to say 2000. This will also enable you to take photographs without a flash. However, the higher you go with your ISO, the more grainier and noisier your image will become.

I am one that quite likes a little grain and noise in my images, it adds and arty texture to the photos.

As I have said before, each DSLR camera is different and with that so will your ISO scales. Most cameras base will be ISO 100 (my Canon 5DS is), this is normally the lowest setting. My canon's ISO then goes up to 6400 - which isn't too high, some cameras will go up to 25600. 

I think about ISO numbers as a scale low to high. Double the ISO, the sensitivity to light then doubles and the speed at which you take your photos doubles. 

If you shoot on ISO 200, it will be twice as sensitive to the light around you as an ISO setting of 100. An ISO setting of 100 will take 1 second to capture, when you double the ISO setting to 200, it takes 1/2 a second to capture the same image.

Experiment with your camera, try and shoot a child running or bird flying. You will need to increase your ISO to around the 800 mark to take the photo at 1/8th of a second. Although with this, you're increasing the camera's sensitivity to the light ( especially if it's a sunny day) and with that, it might mean you have a completely white shot!

Have a look at my ISO cheat sheet below. Put your camera on Aperture Priority (AV) - remembering everything from my first tutorial and play around with your ISO outside.


I hope this tutorial has been helpful! Up next is Shutter Speed, this is the last tutorial on the three principles to photography.

“Photography is a way of feeling, of touching, of loving. What you have caught on film is captured forever… It remembers little things, long after you have forgotten everything.”
Aaron Siskind

The Wondering Dreamer x