In the ” Photographic Novice Training Course ” held every month, we have been teaching students the relationship between “aperture, shutter, and ISO”, and shared the ability to adjust the aperture, shutter, and ISO values in different environments. Different settings of the three basic elements of photography will affect the exposure, but sometimes during the actual shooting, “fast, fierce, accurate” must be done to capture the wonderful moment. At this time, students can use the automatic ISO Mode (Auto ISO) to help shooting!
What is Auto ISO?
Usually in aperture priority, shutter priority, or full manual mode (except automatic mode), you need to adjust the ISO value to a value before shooting. For example, in a bright environment, the ISO value will be lower to maintain the quality of the photo; In many cases, high ISO is used to increase the sensitivity and keep the shutter at a safe shutter (when held). But sometimes when the light changes greatly (such as from indoor to outdoor or different light sources on the scene), in addition to adjusting the aperture and shutter, we must quickly set the ISO value to take high-quality photos. Make the shooting speed slower, and Auto ISO can effectively solve this problem!
Assuming the use of A-mode, the principle of Auto ISO is that the camera will be based on the camera’s built-in metering, the aperture adjusted by the photographer and the “slowest shutter/highest sensitivity” (later (Explanation) to automatically set the ISO, so when you only need to focus on adjusting the aperture and composition, the camera will set the best shutter and ISO for you, saving a lot of time!
Things to watch out for when using Auto ISO
When using Auto ISO, we need to pay attention to the following details:
- You must be careful to set the “Preset Slowest Shutter”
Usually in the “Auto ISO” option in the Menu. You can also find a place for you to set the slowest shutter, indicating that the camera cannot be slower than this value at any time. Important for “safe shutter”! For example, when using a 16mm wide-angle lens in hand, we will set this slowest shutter value to 1/50 second, so that the shutter will always stay within the safety shutter; and when using 200mm telephoto, we will set a maximum of 1/200 second. Slow shutter so you don’t have to worry about camera shake when shooting!
- Set the “highest sensitivity” according to the camera quality.
The “Highest sensitivity” option is the highest sensitivity that the camera will set. Usually, I will set it to the highest level that can be set. For example, the highest ISO allowed by the camera is 6400. I will Set this to ISO3200 so that the photos will not have too much noise.
- In the Final Analysis
Different metering methods will affect the ISO value. The camera will determine the ISO value according to the current metering. Therefore, we must be careful to use the appropriate metering mode. If you are not sure which one to use, select “All-zone metering” (Or similar) now!
When can’t I use Auto ISO?
Although the Auto ISO is very convenient (especially when shooting fast, such as when shooting events), it is sometimes unavailable, such as when shooting night scenes, light, and graffiti, car tracks, or when the shutter value is adjusted by itself (manual mode, when using a tripod). At these times, we need to ensure that the ISO is low to maintain the quality of the photo, and the shutter is slow. Turning on the automatic ISO will cause the camera to set a high ISO by itself, and it will lose its meaning. Please be careful!
Many predecessors of photography do not advocate the use of automatic ISOs, but based on past shooting experience, I recommend that beginners to use new technology that can facilitate their own, so that shooting is easier. And the sense of success in taking good pictures is the driving force for further learning.