ISO is the second part of the “manual triangle” that I’d love to share with you today. By now, you should all be familiar with aperture (and if you aren’t, pop on over to last week’s blog here!). ISO, in my opinion, is the hardest part of manual to explain. To put it simply, ISO is the level of sensitivity your camera has to light. The lower the ISO, the less sensitive your camera is to light, and the higher the ISO, the more sensitive it is to light. As you increase the ISO, your camera creates “artificial light” to brighten the image in camera. The reason why more expensive cameras do better in low light situations is because the sensor is larger and they can handle higher ISO’s. I have a Nikon D750, and it is incredibly good in low-light situations, and I’ll explain a little bit more about that here in a minute.

I always recommend your ISO to be as low as it can possibly be while still maintaining proper exposure. This means that when I am shooting outside during daylight, my ISO is at 100. Because there is so much available light, there really is no need to increase the ISO. However, as it gets darker outside or if you are inside and choose not to use a flash, the ISO needs to increase. It’s always best to stick to a low ISO to 1) retain the most detail in the image and 2) have the highest quality image in camera.

Now what do I mean about “quality.” Well, as you increase the ISO on your camera to compensate for lack of available light, your camera creates artificial light to brighten the image. However, with this comes something I like to call “noise.” This is the extra grain that you see in an image. The higher the ISO, the more grain in your image and less details are captured. The sensor in my camera is very high quality, which means that I can jack my ISO extremely high without getting too much noise in the picture. However, with a crop sensor camera, it is much more difficult to do that without sacrificing the quality of the image.There are some occasions where I think that it is completely appropriate to jack the ISO and “embrace the grain” as I like to say. As a photographer, I would rather capture the moment with a little bit of grain than miss it all together.

Now that we know a little bit more about ISO, how do you think I use that to set my ISO in manual? Well, when I start to set my camera on manual, the first thing I manipulate is aperture, like we talked about last week. The second thing that I set is my ISO. Because I typically shoot outside, it is almost always at 100. Pretty easy, right?? That means that easiest way for me to control exposure on manual is through the third part of the triangle: shutter speed. This, my friends, is something that I’ll share about next week. Happy snapping!