At the opening of the new Leica Store in Sydney I ran a mini-workshop called Photo Fundamentals in which I ran through some of the basics. This was well received by guests so I thought I’d reiterate some of the things I talked about.
Digital imaging has meant that it’s now quite easy to do things with an image that a few years ago would have seemed almost impossible. Despite all of this newfound creative freedom, the old adage rings true – ‘you only get out what you put in’. Regardless of how clever modern cameras are, having a genuinely solid understanding of the very basics of photography will ultimately help you to produce better quality images.
What is ‘shutter speed’?
In order to record a photograph, the sensor in a camera needs a measured amount of light. This will vary depending on the brightness of the scene and so, to achieve a ‘correct’ overall exposure, the camera needs a way to control the amount of light projected by the lens onto the sensor.
The shutter does this by mechanically controlling the length of time that light will be able to reach the sensor. In its resting position the shutter sits in the path of light entering the camera, right in front of the sensor. When a picture is taken it, the shutter moves out of the way – allowing light to pass through to the sensor before returning once again to it’s resting position. The time that the shutter is out of the way is measured in seconds or fractions of a second and is referred to as the shutter speed. To cover as many lighting situations as possible, modern cameras have a huge shutter speed range that can stretch from 30 seconds to an incredibly brief 1/8000th of a second.
Why is it important to be able to control the shutter speed?
Being able to alter the camera’s shutter speed does a lot more than simply control the amount of light needed for a correct exposure. It can also be used to control the amount of motion blur in the picture. If you have ever taken photos in low light (especially without a flash) then you’ve probably noticed that any movement of you or your subject gives you a blurry image. This is because when it’s dark the shutter has to be open for longer so the imaging sensor can receive enough light. If the subject moves within that ‘open’ time then the movement is recorded as ‘blurred’ in the photo. In bright light this is much less of a problem because the shutter is only open for a fraction of a second, effectively freezing any motion in the frame because the subject has not had time to move far enough to be recorded as a blur.
Normally, when set to fully automatic, the camera will try to set the fastest shutter speed possible given the available light levels. This is so that the chances of camera shake and blurring are kept to a minimum, resulting in clearer, crisper photos. However, knowing that shutter speed controls how motion is captured, it’s possible to use it in creative ways too.
As a general rule of thumb the longer the shutter is open, the more motion blur we can introduce to the picture – if we choose to.
Fast or slow?
Take the classic example of a waterfall or other water scenes. Using a longer (shorter, lower) shutter speed means that anything moving within the frame, in this case the water, becomes blurred because it records as a line rather than a dot or point. The result is the classic image of smooth water like this one from Fiji. I shot this using a tripod to hold the camera steady using a shutter speed of 4 seconds on the Leica SL with the 18mm Elmar-M.
So far we have looked at how slow shutter speeds can be used to great effect by adding motion blur to our pictures. It’s also possible, and often essential, to use fast (short, high) shutter speeds such as 1/1000 sec or higher to freeze the action, capturing a moment in time that would otherwise be impossible to see.
The photo of a cattle muster at the beginning of the article was also captured using a fast shutter speed of over 1/1000 sec. This is more of a classic ‘action’ shot where you need to use a high shutter speed to freeze the movement of the cattle and the riders.
Even when the subject itself is motionless, you might not be. High shutter speeds allow you to take sharp photos when your are moving rapidly yourself – like shooting out of a helicopter with the door off, being buffeted by the prop wash. At times like this a high shutter speed will counter camera shake and let you capture a sharp image.
Controlling motion blur, or eliminating it altogether, is an essential skill when it comes to conveying an impression of movement in our pictures. Having an understanding of shutter speeds and their effects on an image is not only important in terms of achieving correctly exposed photos, it also opens up a whole lot of creative possibilities. It gives you, the photographer, control over time itself; it makes it possible to capture moments that reveal something about the subject that we would otherwise never see.