Shutter Speed is one of three determining factors used to control exposure.
In photography, Shutter Speed is the time between the shutter closing, opening and closing again. In other words, the amount of time the sensor is exposed to light.
Unlike aperture, the exposure stops for shutter times are easy to remember with the stop being proportional to the exposure time.
1/500th of a second is one stop faster than 1/250th of a second and lets in half as much light.
Understanding shutter speeds is essential to taking full creative control of the camera. If the shutter is left open for too long you risk over exposing your image. Too short and you risk leaving the image dark and lacking in detail.
I will speak about creative effects later.
Shutter speeds can range from milliseconds, to minutes depending on the shot you want.
In addition to standard shutter speeds you can use functions such as ‘Bulb’ or ‘Time’ to hold the shutter open for extended lengths of time.
On a normal scale, you’ll see the most commonly used shutter speeds ranging from one second to 1/500th of a second. However, most cameras will have a range of at least 30 seconds to 1/8000th second.
As with Aperture, it is usually possible to select ⅓ or ½ of a stop on most modern cameras.
A general rule of thumb when shooting hand-held, is that any less than 1/60 will require some sort of support, like a tripod, unless motion blur is something you’re looking for in your shot.
Focal length is also a big consideration when assessing which shutter speed to use – something we will cover later.
As both camera (IBIS) and lens stabilisers (sometimes known as OIS, OS, VR or ILIS) improve, shooting at lower speeds becomes easier so please keep this in mind and do not take my suggestions as divine rule.
Part 3 – Shutter Speed and Exposure
So what is the correct shutter speed? This will depend on how much light is in the scene and what you want to capture.
For general shooting, outdoors on a sunny day you might need 1/500 whereas you’ll need to slow it down if indoors, maybe 1/125 or lower.
Below you’ll see a set of images taken changing only the shutter speed to show exactly how much each stop affects the exposure of an image.
Focal Plane Shutter:
This basically means a curtain (or set of curtains), move across the sensor either vertically or horizontally for exposure.
Be careful when using a flash at high speeds as not all are compatible (Super FP).
It is important for any photographer to know and understand their limits when it comes to shutter speed.
With Image Stabilisers and Monopods, gimbals and exoskeletal stabilisers there are no drop dead rules for how slow a shutter speed you can use, it is something you really need to test yourself.
To test your limits, you need to take some test shots.
Take the shutter speed down to around 1/60sec and take a shot. Zoom in 100% and check the details, lights or contrasting edges. If they are still sharp, reduce the shutter speed and take another shot, inspecting it again.
Continue this until you see some camera shake or movement in the image; this is now your lowest shutter speed for hand held photography ‘at that focal length’.
Focal length is very important as the longer the focal length the more the movement is visible.
Some slight shake 200 meters in front of you will be greatly magnified 2km from you and shows a lot sooner than you may think.
Luckily there is a rule for this.
Basically put, you use 1/100th of a second for every mm of focal length (in 35mm terms).
So if you use a lens at 300mm on a Micro Four-Thirds camera, that’s a focal length of 600mm equivalent.
600 x 100 = 600 = a 1/600th second minimum exposure speed
The 500 Rule:
The 500 rule is used in case of shooting the night sky.
When we look up, the stars and moon look quite still. This however is incorrect and they do move at a steady pace.
To avoid any movement in the stars simply divide 500 by the focal length in 35mm terms.
So if you use a lens at 7mm on a Micro Four-Thirds camera, that’s a focal length of 14mm equivalent.
500 ÷ 14 = 35.7 = a 35 second maximum exposure speed
The rolling shutter is actually quite difficult to explain in writing, so I would ask you please to take a few minutes to watch the below YouTube video which is very good at describing this.
Basically put the rolling shutter is the distortion and movement of the image due to the way the shutter curtain closes or the way the electronic shutter deactivates the sensor.