Needless to say, photography has become one of the most popular interests today. While photography is not exactly rocket science, there are fundamental that you should commit to memory in order to capture a high-quality photo. Aside from the Shutter Speed and the Aperture, the ISO is one of the three pillars of photography that all photographers will need to fully understand. Using ISO in photography can give a whole lot of difference in the quality of the image and the story you wish to convey with your photos. Let’s go through the fundamentals of ISO.
ISO: In a Nutshell
When we speak of “ISO”, we generally refer to how sensitive your camera is to the source or available light. As a general rule, lower ISO number means lower sensitivity to light. And the higher the ISO number is, the more sensitive your camera is to light. The sensitivity of the light is dependent on the most important component of your camera called the “image sensor”. What the sensor does is it gathers the light so it can be transformed into an image.
When the sensitivity is increased, your camera can actually capture any image even in environments with very low light and without the need for a flash. However, this is not always a good solution — higher sensitivity actually makes your pictures prone to “grains” or what we also call ” noise” in photography. In other words, using ISO correctly in photography can help you capture images of the best quality.
Each camera, depending on the brand and the type, have a different Base ISO or the lower ISO number which the sensor can use to produce an image without the grain or noise. For example, Canon cameras usually have Base ISO of 100 while other cameras are equipped with a Base ISO of 200.
Using ISO in photography can also be easily remembered through various basic principles. For instance, beginners in photography are usually taught this: “In order capture the image with the highest quality, stick to the Base ISO.” Sounds easy, right? Well, No! In fact, it is not always possible to follow this rule, especially when working in environments of low lights. Learning more about ISO and the ISO speed can help you understand how to better capture images taking into account these two components.
From Base ISO to ISO Speed
If you would look at the ISO setting of cameras you would find that the Base ISO typically begins from 100 or 200 and the value increases by 200%. Therefore, the ISO sequence that cameras have is usually 100, 200, 400, 800, and so on. This means that as the value increases, the sensitivity of the sensor doubles as well. To illustrate an example, ISO 200 is twice more sensitive than ISO100, or ISO 800 is eight times more light sensitive than the ISO 100. So, what does all of this mean? If you take a sensor with ISO 1600, it means that it would need 16 times less light to capture an image than ISO 100 to capture the same image. This is now what we call theISO Speed, an element you need to learn to obtain the best image result in using ISO in photography.
As a rule, the ISO speed for ISO 100 is 1 second. So, when you use ISO 200, it means you only need1/2 of a second to capture an image. ISO 400 would require you only 1/4 of a second to capture an image of the best quality. In short, the higher the ISO value means the less time required to capture an image. Can you tell me how much time you need to take the best image when using ISO 1600?
When Is it Recommended to Use Low and High ISO?
Let”s focus on using low ISO first. Generally, when there is plenty of light in the environment where you intend to capture an image, it is recommended to go for the base ISO as much as possible. This would allow you to retain most of the details of the image and minimize the noise. On the other hand, when there is insufficient light in the environment where you wish to take the photo, you may need to increase the ISO to be able to capture a clear image without any blur.
Note that almost all cameras with “AUTO ISO” capability will automatically determine the level of sensitivity to light needed to capture a useable picture. In low light photos, you will almost always need to use a software of some type to smooth out the grain or “Denoise” the photograph. Just be careful not to overuse these tools. Strike a healthy balance when using them.
In conclusion, using ISO in photography can help even the beginners capture the highest quality image depending on the light available and the time needed. Furthermore, using the right ISO can also help keep the “noise” down.