Pixel Power: picking the correct shutter speed

Hello Readers! Welcome back to Pixel Power. Last column we talked about ISO settings and how they effect your photographs. In this month’s column we’ll be discussing shutter speed and how shutter speed choice impacts your photography. You will need to set your camera’s shooting mode to shutter priority or manual, to set your own shutter speed.

Your camera’s shutter is like a curtain housed in front of your camera’s sensor that stays closed until you take a photograph. When the camera fires, the shutter opens and fully exposes the camera sensor to the light that passes through your lens. Your camera’s sensor collects light for that brief time period when your shutter opens.

Shutter speed is thus the length of time your camera’s shutter is open to exposed light onto your camera’s sensor. Shutter speeds are typically measured in fractions of a second, when they are under a second. For example, when you turn your camera’s shutter speed dial to “60” that means your shutter will stay open 1/60th of a second when you take your photograph. If you turn your shutter up to “250” , or 1/250th of a second, that’s four milliseconds your shutter is open!

So what does this mean? The higher you set your camera’s shutter speed, the more you will freeze any movement you’re photographing because your shutter is not open very long. If the shutter speed is slow, or set to a lower number, under 1/60th of a second, moving objects start to appear blurred.

Your reaction may be, Great! I’ll just push my shutter speed up high and all my photographs will be tack sharp! That’s true to some extent, but here’s where the ying and yang of photography occurs. If you want your shutter to stay open just a short time, you need a lot of light because your sensor does not have a lot of time to collect light to expose your photograph if your camera’s sensor is only open 1/250th of a second! Thus you will have to raise your ISO setting and/or open up your lens aperture setting when you raise your shutter speed setting, so you get enough light to your camera’s sensor.

A good rule of thumb for shutter speed settings, if you’re hand holding your camera (no tripod), is that your shutter speed should not go below 1x the longest focal length of your lens. If your lens is an 18-135 lens, try not to let your shutter speed fall below 1/125th of a second.

This month’s homework: set your camera to shutter priority and your camera’s ISO to at least 800. Go outside and move your shutter speed up, one click at a time, starting at 1/125th of a second, and take photographs of hose water spraying in the air. Do the same thing with your kids running by, or cars driving by. Notice how shutter speed choice effects the clarity of your images. We’ll talk more about lens apertures next month.

Happy Practicing! – EB Taylor

Leave a Reply

Your email address will not be published. Required fields are marked *