Have you ever noticed a camera button labeled ISO and been puzzled as to its purpose? Well, it is an integral component of your camera’s exposure settings and must be utilized accordingly.
The higher your ISO setting, the more sensitive your camera sensor is to light. This is especially true when shooting in low-lighting conditions or while capturing fast-moving subjects.
What is ISO in photography and how to use it
If you are new to photography, one of the first settings that you should become familiar with is ISO. This component of the exposure triangle, along with aperture and shutter speed, has a significant influence on your photos.
For bright environments, a lower ISO setting is best when detail and dynamic range are more important than image noise. On the other hand, a high ISO can help boost exposure in darker conditions.
Digital cameras utilize ISO (ISO) values which indicate how sensitive their sensors are to light. Higher values amplify the signal, creating more digital noise.
Due to this, it can be challenging to achieve clean, usable images at higher ISO values. As a general rule, only increase your ISO if you cannot brighten the photo by increasing the shutter speed or aperture value.
Selecting the right ISO
ISO is an integral element of your camera’s exposure triangle, alongside shutter speed and aperture. To get the best results in any given situation, it’s important to use the correct ISO setting.
When selecting a low ISO value for your camera’s sensor, the lowest sensitivity possible allows your sensor to capture the maximum amount of detail possible. This is especially useful for portrait photography or any subjects that require fine details and no noise.
Alternatively, you can select a high ISO value and increase your camera’s sensitivity to more light, which is especially helpful in low-light conditions. Unfortunately, this will also increase sensitivity to noise which could result in grainy images.
When seeking a clean and crisp image free from noise, opt for the lowest ISO possible. This will enable you to capture more dynamic range and depth in your photos without sacrificing image quality.
Photography tips for ISO
If you’re new to photography or often use auto mode, it is essential that you understand ISO in photography. ISO plays an integral role in controlling light and ensuring your photos look their best.
As a general rule, shoot in bright conditions using the lowest ISO value possible. This makes your camera’s sensor least sensitive to light and thus produces less grain or noise in the final image.
However, if you’re photographing in darker environments, it may be beneficial to increase your ISO so that the image is properly exposed. Doing this helps combat the darkness and produces a brighter picture.
Additionally, when trying to freeze motion, it’s essential to increase your ISO so you can use a faster shutter speed in order to keep subjects sharp and distinct. This is especially useful when photographing at night or under low light conditions as well.
Common ISO Values
The ISO is a measurement system used to gauge the sensitivity of digital camera sensors or films to light. You’ll typically see its ISO number displayed on your camera’s LCD display, and you can use it to alter your sensitivity settings accordingly.
Common ISO values you’ll see on a camera include:
ISO 100
ISO 200
ISO 400
ISO 800
ISO 1600
ISO 3200
There are many more ISO values, but the range above will cover most photo shoots.
If you’re familiar with the fundamentals of photography, then you know that each pixel on your camera’s image sensor receives a specific charge when it absorbs light. This charge is then converted to an analog voltage and amplified so an ADC can read it.
The amplification process also produces some digital noise, which most modern cameras do a great job of eliminating. This noise can be caused by saturation/dark current across photodiodes, random thermally-released electrons in sensors or processing electronics (photon noise), and charge carrier movement across depletion regions of sensors (back-end read noise).
What is Base ISO?
The base ISO, or unamplified sensitivity of your camera’s sensor, is the value you should use to optimize image quality and minimize noise in photos. This value should always remain unchanged over time to maintain consistent, clear photos.
Some cameras come with a native ISO of 100 or 200, while others offer an extended range that goes down to ISO 50 or up to 25,600. Unfortunately, these higher values are simulated within the camera and often result in decreased image quality.
Digital sensors differ from film in that they don’t rely on photosensitive crystal density to determine sensitivity. Instead, your digital camera’s sensor sensitivity is determined by a combination of shutter speed, aperture, and ISO setting.
Many photographers mistakenly believe that increasing their ISO setting increases the sensitivity of their camera’s sensor, but this is not entirely accurate. Instead, higher ISO values add amplification to the signal from the sensor which causes it to brighten more significantly. Furthermore, this amplified signal increases noise in images – often visible as random patterns – making them appear grainier.
Low vs High ISO Noise Visibility
The ISO setting on a camera indicates how sensitive its image sensor is to light. This factor plays an important role in producing realistic-looking photographs.
Many people mistakenly assume that higher ISO settings produce grainier photos. This isn’t always the case, and it can be beneficial to experiment with different ISO settings in various lighting conditions.
However, higher ISO settings can introduce digital noise into your pictures, creating a grainy and less pleasing visual appearance.
When shooting with a high ISO, two types of digital noise may appear, being color and luminance noise. Both can be difficult to remove.
Noise can be reduced through digital noise reduction systems in the camera or post-processing filters. However, it’s generally best to avoid high ISO settings for most situations.
When to Use Low ISO
ISO is an integral factor in any photographer’s exposure triangle. Along with aperture and shutter speed, ISO determines the quality of a photograph.
As a general rule, lower ISO values result in better-looking photos. However, you must be selective when setting your camera’s ISO setting.
When photographing in low light conditions, higher ISO settings will amplify the signal and introduce noise. In some cases, this can result in images appearing grainier than if taken at a lower ISO setting.
Though high ISO settings can have their drawbacks, there are times when they can be beneficial. For instance, when photographing an important moment such as Beyonce at a park or a child taking their first steps in the dark.
When to Use High ISO
High ISO settings can have an adverse effect on image quality, especially when shooting color images. Color images may appear darker, lack details and have a grainy appearance; thus why most photographers opt to shoot in JPEG format.
Low ISO settings enable you to capture more details and achieve greater color depth in your images. Furthermore, they permit using a faster shutter speed and smaller aperture for motion blur prevention.
However, there are certain instances when a higher ISO may be beneficial. This is particularly true when taking photos indoors at dark places such as museums, art galleries and aquariums where there is no flash available.
When shooting event or sports photos, it is essential to capture as much detail in both highlights and shadows of a scene as possible. This can be accomplished with lower ISO settings; however, an increased ISO will result in noisier highlights and shadows.
