How to Shoot Manual: ISO
Along with shutter speed and aperture, ISO is one of the three pillars of photography. It is an essential tool to know how to use when it comes to shooting manual on your DSLR. Although many people are hesitant when it comes to adjusting their ISO manually, it can produce great results when it is used correctly. ISO is measured on your camera most commonly as 100, 200, 400, 800, 1600, 3200, 6400, etc. Depending on your camera, ISO can go up much higher, but the most common setting ends at 12800.
To define it simply, ISO measures the sensitivity of the camera`s sensor to light. When the camera is set on the lowest ISO number, 100, the sensor is the least sensitive to light. When it is set on the highest ISO, 12800, it is the most sensitive to light. ISO is used in dark conditions, where you do not have a tripod or cannot use a flash. In these circumstances, such as theatre performances, concerts or parties, you would need to put up your ISO in order for the camera to detect more light. Remember that by pushing up your ISO, your camera`s sensitivity to light will increase, and you will therefore create a photograph that has better lighting for that situation.
The reason may people are weary of using their ISO is because putting it up too high causes what is known as ‘noise’. Noise in a photograph refers to the fuzziness that can sometimes appear in an image. It is also known as ‘grain’, and tends to be very distracting when it is particularly strong in an image. Some camera models- unfortunately, it happens to be the more expensive ones- can deal with noise better than others. You just need to experiment with your camera and see what your absolute limit is.
Having said that, the lack of available lighting in certain situations requires you to push up your ISO. When you find yourself taking photographs in one of these situations, it is often better not to compromise your other settings. For example, when taking photographs in a theatre where flash is not allowed, you will have to use your ISO to compensate for the lack of light. You can attempt to lower your aperture to let in more light, but it cannot be so low that your depth of field is too small to capture everyone one stage, and your shutter speed will have to be relatively high to capture sharp images as the actors move around. You cannot compromise these two settings, and as a result, will have to push up your ISO. This is a solution that many photographers use, and the results tend to be really good. It is just important to know what the limit on your camera is, and know how to work around that. For something like this, practice is really the most important tool as you get to know your camera.
However, many people enjoy the mood that grain creates. Graininess is often done on purpose in photography to add a vintage feel to images, similar to that of black and white photographs. Like anything in photography, these are just guidelines to follow- the creative aspect of your photographs is up to you!