Adding to your already super-cool manual mode powers, we’re giving you a monkey wrench today: ISO settings. In my last manual mode lesson, I told you about using shutters (how fast your camera takes a photo) and apertures (how much light is allowed in when you take a photo) to control exposure (how bright your photo is), but there is one more tool you can use to master your camera.
ISO is essentially the sensitivity of your digital camera’s sensor to light. Think of it like skin – if you’re a fair lady from the North Pole, you will burn easily in the sun, but if you’re bronzalicious and hail from the equator, you will likely take longer to burn on a sunny day. That’s pretty much how it all works.
ISO affects both shutter speed and aperture, which is why you need to understand both of those elements first (to learn more, click here). For example, a higher ISO with a long shutter speed is like being fair skinned and sitting in the sun for an hour without sunblock – you will definitely have an uneven, unbalanced color after that! With fair skin, you may only need 10 minutes to get a tan, so turn down your shutter when you turn up the ISO in order to maintain a normal exposure. Likewise, if you’re dark skinned, an hour in the sun might be just right for you, so turn up the shutter when you turn down the ISO to keep things balanced.
Keeping your camera on ISO 100 is suitable for most photos and is likely what your camera will stay at if you only use it in Auto Mode, but turning up the ISO can help you in other ways. One way in particular is in dark places where you need a short exposure to minimize blur but lots of light to expose your photo. By turning up the ISO and choosing a fast shutter speed, you can minimize blur and increase your camera’s sensitivity to light, hopefully producing an evenly exposed photo.
However, there are drawbacks. Whenever you increase the ISO, you are also increasing the grain or noise (that speckle effect that happens sometimes in photos). Sometimes you may actually want this effect in your photos but if you don’t, you’ll have to turn down the ISO to get rid of it.
Here are some examples of my early experiments with ISO settings:
The top left was basically on auto mode. There was no noise and the blur was fine, but I wanted it to be brighter. My second photo, the top right, was me going to the extreme (I turned up the ISO all the way and kept my camera on shutter priority with a fast speed). The result was slightly darker than the first one because even though I increased the ISO, I also increased the shutter speed (not what I wanted).
The bottom left photo was my third attempt; I turned down the shutter and turned up the aperture. Finally I got the right color, but it was still so grainy. How could I have fixed this? I should have turned down the ISO to 800, turned down the aperture a bit (maybe to f/11) so more light could get in, and left the shutter speed. Instead, I just slowed down the shutter speed even more (bottom right photo) because I didn’t really know what I was doing. The result: definitely overexposed. So I gave up and packed up for the night.
I didn’t get the photo I set out to take but I came close. Looking back now, I can see how really valuable this little experiment with ISO settings really was. If you really want to learn how to use your camera and how to master all of its tools, you have to practice. Go out with your camera and try all of the settings, and take a moment to review your photos and fix them. The practice won’t be wasted! Alternatively, try using this camera simulator as a testing place for ISO, Shutter and Aperture settings.
Your challenge this week – go out again and try using your camera in one of its manual modes: Shutter Priority, Aperture Priority, or full Manual Mode. Don’t forget to play with the ISO setting and see what kinds of results you can get. When you’ve finished, come back and show us your best shot!
