Back to Basics: ISO, Shutter Speed & Aperture
- Understanding Exposure, 3rd Edition: How to Shoot Great Photographs with Any Camera
- DSLR Photography for Beginners: Take 10 Times Better Pictures in 48 Hours or Less! Best Way to Learn Digital Photography, Master Your DSLR Camera & Improve Your Digital SLR Photography Skills
- Tony Northrup's DSLR Book: How to Create Stunning Digital Photography
One thing I love about photography is that unlike other fields of work that rely on technology a lot, the principles are still the same no matter how advanced the cameras get. You still have the same settings no matter what name is written on your camera and they have pretty much the same impact. When learning the technical side of photography, it all comes down to the three most important elements: ISO, shutter speed and aperture. Think of them as a universal language that will allow you to “talk” to any camera and make it work exactly the way you want to. There’s no going forward without knowing these three exposure parameters, so make sure you pay close attention.
Knowing how to balance these three settings is key to getting a correct exposure in any lighting condition. Let’s start with the ISO which is the only setting that varies from one camera to another depending on category, age and price range. The ISO is the camera sensor’s sensitivity to light. The higher you turn it up the more sensitive it becomes to light. That means it will allow your camera to “see” more in less than ideal situations. Most of today’s cameras are pretty solid performers when it comes to high ISO values and some are quite jaw dropping like the Sony A7S II and A7R II. Smaller sensors are usually less capable of producing clean, noise free images at high values, but there have been significant improvements, especially in the Micro 4/3 format.
The shutter speed of your camera works pretty much like an eye lid. It opens and closes just enough to let the light enter the camera. The longer you keep it open the more light will enter and expose the sensor. When shooting handheld, it’s usually not advised to use shutter speeds slower than 1/30s, although with an optical stabilization system in the lens or the camera, it’s possible to shoot slow as 1/4s handheld.
The aperture is pretty much like the iris in your eye, although apart from the amount of light that enters the lens it also controls depth of field. The wider the aperture, the more light will enter the lens and the more blurred the background will be presuming you have a centered subject.
Fine tuning these three elements and learning the connection between them is crucial. It might seem a little hard for some of you, but after a while it’s a simple matter or practice before you instinctively choose the best values for a correct exposure.
Here is a good education video that studies these three elements from Tek Syndicate.