The triangle of light, overview.
In the days of film, there was only tree things that a photographer had to worry about once the film was inserted. These were how many shots do I have left, getting the exposure and aperture right and getting a beautiful photograph goes without saying but this is a technical post and we will forgo the actual photograph framing, beauty and quality for a while.
In the digital age, not much has changed except that we are no longer limited by film but there is a new factor, ISO. In the analogue days this was a constant once the film was in the body. This brings me to the triangle of light exposure, aperture and sensitivity.
Each of these factors have now become vital from the time you pickup your camera. Each have their own pros and cons, our jobs as photographers is to mitigate these to achieve the best possible photograph.
Let’s talk about each factor individually before we address them in unison.
- Exposure, the time taken to capture the image, measured in seconds or parts thereof.
Pro Cons Higher Speeds (1/1000s) Freezing motion No low light capability Lower Speeds (2s) Low light capability Motion blur - Aperture, the amount of light allowed to traverse to the sensor at any time, measured in f-stops or parts thereof.
Pro Cons Higher Apertures (f/1.4) Low light capability Low depth of field Lower Apertures (f/22) High Depth of Field No low light capability - Sensitivity, the light sensitivity of the sensor, measured in ISO
Pro Cons Lower ISO (100) Sharper image, no noise No low light capability Lower ISO (1600) Low light capability More noise, less sharpness
I will go deeper on each subject in further posts.
So what does it all mean? Generally, it means that, as photographers, we often have to compromise on something. The aim is to get the middle of the triangle all the time, but it is seldom possible.
The good news is that there are very good tools for one of those factors, noise…
