ISO

What is ISO and how does it affect my photography?

Lets dive in!

ISO, short for International Organization for Standardization, is a measurement of a camera's sensitivity to light. Woah, acronyms are everywhere. It is a fundamental to photography and something to master on your journy.

The lower the ISO number, the less sensitive the camera is to light, and the less noise (or grain) will appear in the final image. The higher the ISO number, the more sensitive the camera is to light, but the more noise will appear in the final image.

ISO can increase the light by one stop every time it is doubled. For example, changing your ISO settings from 100 to ISO 200 doubles the light. Increasing exposure by one stop. ISO 200 to ISO 400 doubles the light increasing exposure by one stop. ISO 400 to ISO 800 to ISO 1600 and so on. goind down ISO 800 to ISO 400 half the light and moves your exposure down a stop.

Example of a ISO sequence 100, 200, 400, 800, 1600, 3200, 6400, 12800, 25600, 51200.

Using that knowledge can help you property expose your image.

When a camera's sensor is exposed to light, it collects photons and converts them into electrical signals, which are then processed by the camera's image processor to create a digital image. ISO refers to the sensitivity of the camera's sensor to these photons, and it can be adjusted to capture more or less light in a given scene.

In traditional film photography, ISO was determined by the film stock used, and photographers had to physically change the film in order to change the ISO. With digital cameras, however, the ISO can be easily adjusted in-camera, which allows for greater flexibility and creativity in capturing a scene.

ISO can be creatively used in several ways to achieve a certain look or effect in your image. For example:

• High ISO can be used to create a grainy, vintage look, reminiscent of film photography. This can be especially useful for black and white photography.

• Using high ISO in low light conditions, such as at night, can allow you to capture an image without the need for a flash or a tripod. keep shutter speeds fast, and handheld the camera.

• Using a low ISO in bright light conditions, such as in the middle of a sunny day, can help to maintain image quality and reduce the risk of overexposure. A low ISO, such as ISO 100 or 200, will allow you to use a smaller aperture and slower shutter speed while still maintaining a proper exposure. This can be useful for landscape photography where a large depth of field is desired and motion blur is not a concern.

• By controlling ISO in combination with aperture and shutter speed, you can create a motion blur effect, where a moving subject is captured in sharp focus against a blurred background. This can be useful for creating a sense of movement and dynamism in a photo, for example, a car driving at night or a dancing person in a party.

• Lowering the ISO can also be useful when working in studio conditions or any controlled environment, allowing you to use flash or continuous lighting, so you can use smaller apertures and slower shutter speeds, helping to keep the background blurrier and highlighting the main subject.

The native ISO and maximum ISO of a camera are determined by several factors, including the technology and design of the camera's image sensor, image processing capabilities and camera firmware.

A camera's image sensor is the device that captures light and converts it into electrical signals. It's made up of millions of light-sensitive photodiodes, also known as photosites. These photodiodes are grouped together in a grid-like structure called a pixel array. The number and size of these photodiodes determine the camera's native ISO and maximum ISO. A sensor with a higher number of larger photodiodes will have a higher native ISO and maximum ISO than a sensor with a lower number of smaller photodiodes. I know it sounds technical but I wanted to be accurate in the How it works.

Additionally, the image processing capabilities of a camera also play a role in determining the native and maximum ISO. Image processors are responsible for converting the raw data from the image sensor into a final image. They can use algorithms to improve the image quality, reduce noise and increase the camera's ISO capabilities. Cameras with better image processors will be able to handle higher ISOs with less noise and greater image quality.

The firmware of the camera also plays a role, as it can be programmed to limit or extend the ISO range of the camera for various reasons, such as to increase image quality or to extend battery life. The firmware can also be updated by the manufacturer to enhance the camera's capabilities, such as increasing the maximum ISO or improving the noise reduction.

Every camera model may very the native ISO, or lowest ISO setting and the highest ISO number before grain and noise are seen. Your milage may very, check your manual to find out your native and max ISO.

ISO is an important aspect of photography and one of the three elements of the exposure triangle, and by mastering its use, it can help you to become more creative with your photography and achieve different looks and effects in your images. The key is to experiment with different ISO settings and understand how they interact with other camera settings with your gear.

ISO Task

Lets use this info in the real world and get to know our gear.

• Set your camera up on a tripod in Manuel mode, if you don't have a tripod hold the camera as steady as possible.

• Set ISO to your cameras native setting, check your manual to find out what your cameras native ISO. My camera has a native ISO 100

• Aperture on the widest and shutter speed to the correct speed to get the correct exposure.

• We will take a picture of a fixed object about 5 ft away.

• take the second photo at the next ISO sequence and adjust your shutter speed to the correct exposure

• repeat and look at your images for grain, your camera will begin to show grain at different ISO compared to my Camera.

Use this task in different lighting conditions and learn how your gear reacts to different ISO levels.

Looking at the images above you can see grain begin very lightly in the shadows at ISO 800 when we get to ISO 40,000 grain in the image is defined.

Thank you for taking the time to read! I hope this information on ISO helps you improve your photography. Remember to experiment and have fun and see what works best for you and your style. Let me know if you have any questions.

Get out there are take some pictures!

-Thomas Martinez