By Gayle Vehar on | No Comments
Yesterday we talked about how shutter speed works. Today, we will focus on the last of the 3 important elements of the exposure triangle: ISO - a very important setting to use properly if you want to take the best possible photos.
ISO measures the sensitivity of the camera sensor to light.
The term ISO has been carried over from the days of film. Film is made up of little crystal grains. At ISO 100 or 200, those crystal grains are very tiny and need more light to expose them. With ISO 1600 or 3200 film, the crystal grains are larger and thus need less light to expose them. The trade off is that the larger crystal grains are more noticeable and photos are less smooth.
Digital cameras have ISO equivalents. However, with digital cameras it isn’t crystal grains that become noticeable as the ISO numbers get larger, it is pixels that become more noticeable as noise or grain.
At higher ISOs, your camera sensor will need less light to create a nicely exposed photo. However, you will also see more grain/noise in the photo. At lower ISOs, your camera sensor will need more light to create a nicely exposed photo and you will see much less grain/noise in the photo.
(This photos was taken at ISO 6400 on a Nikon D610. At 100% grain is noticeable but not distracting. No noise reduction has been applied.)
As a general rule, you want to keep your ISO as low as possible. However, this does NOT mean that you should always shoot with an ISO of 100.
When photographing indoors there is much less available light than there is when shooting outside in the sun. In these low light situations, you should use whatever light you have available and then raise your ISO as necessary to get a good exposure.
Why? Because capturing a nicely exposed photo is more important than worrying about grain or noise.
Digital cameras have really improved their high ISO capabilities in the last several years. Many current cameras have the ability to shoot at high ISOs with relatively little grain and/or noise.
To adjust ISO on your Canon Camera, press the ISO button and rotate the main command dial. The ISO button is found on the top of the camera in one of the locations on the diagram below.
To adjust ISO on your Nikon entry-level camera, press the "Info" button and using the back circular dial select ISO and then set the number you want and press "OK". Some entry-level Nikon camera's have touch screens that allow you to adjust ISO using the touch screen. TIP: Since setting ISO requires a few steps, consider setting the "Fn" button on the front of your camera to adjust your ISO. Consult your manual for the exact steps to do this.
To adjust ISO on your Nikon pro or semi-pro camera, press the ISO button and rotate the main command dial. The ISO button will either be located on the top or back of your camera depending on the model.
Make sure you remember these general rules about ISO before moving on to the next part of our tutorial:
Lower ISO numbers are less sensitive to light and produce little noise or grain, so use a lower ISO when you have lots of light.
Higher ISO numbers are more sensitive to light but produce more grain or noise, so use a higher ISO when you have less light available.
Make sure to read the rest of our series to help you Master Manual Mode. If you’ve missed any of the posts, you can read/review them at any time by clicking these links!
Day 1. 7 Days to Mastering Manual Mode: Why Shoot in Manual Mode
Day 2. How to Use Your Camera's Light Meter
Day 3. Aperture for Beginners
Day 4. Shutter Speed for Beginners
Day 6. Perfect Exposure: Putting it All Together
Day 7. Practicing Your Way to Manual Mode Perfection
Bonus: free downloadable Mastering Manual Cheat Sheet for use on the go!
Hi!! I am Gayle. I am a wife to my handsome husband and mom to 4 beautiful kids. In my spare time, I am a photographer and blogger at Mom and Camera. I have a passion for sharing my love of photography with others. I teach local photography classes and regularly share photography tips and tricks on my blog. I hang out there a lot—I’d love you to stop by and visit!
Comments