Taken at ISO 800 (shutter speed of 30 seconds and aperture at f/8.0)
ISO has long been called the third corner of the exposure triangle, but was it really? In the film days you couldn’t even change your ISO, except by changing your film. In the early days of digital, you could change your ISO after each shot, which was a definite improvement. But, if you dared to increase the ISO, your picture would probably end up with a lot of digital noise in it. The reality is that most of us were confined to a very narrow range of ISO values when making our exposures.
Times have changed though. Newer cameras offer a lot more flexibility when it comes to ISO. First of all, they are capable of taking pictures at higher ISOs. Cameras now will routinely shoot at ISO 25,600 (and higher), which was almost unheard of just five or six years ago. Secondly, when newer cameras do shoot at higher ISOs, they produce less digital noise. Check out this chart from DxO Mark showing the ability of cameras to shoot at higher ISOs without being ruined by noise:
The chart shows the maximum useable ISO for given cameras introduced over the last 12 years. Notice how the dots are higher on the chart the further you go to the right. The newer cameras are to the right of the graph and the tests show that they can shoot at higher ISO values with less digital noise.
In addition, seemingly mindful of the desire of photographers to change their ISO more frequently, camera manufacturers have made it easier to change ISO on the fly. Some, like Fujifilm, have even put ISO on par with shutter speed and aperture by giving ISO its own dial. As a result, it is easier to change the ISO and it truly has status as an equal partner in the exposure triangle.
Even beyond cameras, however, we now have a much greater ability to remove digital noise from our pictures. Much of this improvement is thanks to Lightroom. With a quick slider adjustment, we can eliminate much digital noise from our pictures, without making them blurry. Further, if you have a severe noise problem, there are dedicated plug-ins like Noiseware and Photo Ninja, designed to reduce noise in your pictures, which have continued to improve.
As a result of all of this, you have a lot more flexibility when it comes to ISO. But how does this really impact your photography? And where should you set your ISO in different situations?
If you are just getting started, you might be bewildered by the numbers, or perhaps don’t even know where to start. If you have been shooting for a long time, you may be locked into some habits that were engrained before all these changes in technology. Either way, here are some tips to help you put ISO to work, to improve your photography.
Tip 1: Start with ISO 200
If you have been shooting for a long time, you might be in the habit of keeping your ISO at 100 to keep noise out of your pictures. As mentioned above, given the state of camera technology, this was a prudent practice. Now, however, there is almost no discernible difference between a shot taken at ISO 200 and ISO 100 in most cameras. You may as well use ISO 200 as a default to give yourself an extra stop of light. It will result in better pictures. How so? In one of two ways:
- It will allow you to use a faster shutter speed, which will make your photos sharper if you are hand holdingAND/OR
- It will allow you to use a smaller aperture to increase your depth of field
By using ISO 200 instead of 100, you will enjoy a little extra flexibility in your exposure settings, without an increase in digital noise. It is pretty much a case of something for nothing.