The camera’s Shutter is one of the three components of the Exposure TriangleExposure Triangle. Its role is to regulate the time the media is exposed to the light whether it is Film or Digital photography. Nothing has changed at the shutter level since the arrival of Digital photography, except maybe the burst mode and we talk about that in a future video and post. The exposition time is usually expressed in fraction of a second, in second and some cases in hours ( hundreds of seconds). Most DSLR would offer you the possibility to fire the shutter at a maximum speed of 1/8000 sec which you would agree is quite fast and if in some rare occasion this would not be enough you could always use a Neutral Density filter but will cover this in another video and post. On the opposite side of the scale, most DSLR would offer the possibility to use set a time value of 30 sec. To achieve a longer exposition, you would need to use the Bulb mode which we will cover as well in another video and post.
How the time scale works1sec, 1/2 sec, 1/4 sec, 1/8 sec, 1/15 sec, 1/30 sec, 1/60 sec, 1/125 sec, 1/250 sec, 1/500 sec, 1/1000 sec, 1/2000 sec, 1/4000 sec, 1/8000 sec. Each time you increase the firing speed to its next value, we call it a stop (just like for the ISO as seen in the ISO). Some cameras will let you increment the Time value by a 1/2 stop or even 1/3 stop to give you more flexibility in your exposure. Each time you either reduce or increase the Time value by a full stop you, in fact, double or divide the exposition time by 2. Subsequently, this means you, in fact, double or divide by two the amount of information coming from the light. Here are some sample exposures I shot as small JPEG, and they aren’t post processed:
So you may be asking yourself: then what Time value should I use and when?Well just as with the ISO it all depends on of the condition you are shooting under. As a matter of a fact, if you are under a lot of light then you may need to use a fast Shutter speed to reduce the amount of information and avoid your exposure to be over exposed. Subsequently, if you are in a dark place like a restaurant or even doing Night photography, you may need to slow down the Shutter speed (i.e several second or minutes). The above explanation is not exhaustive and is only intended to help us understand the basics of photography. Indeed, alike with the ISO, there is some occasion when you would use a slow shutter speed in bright day light, but this will be covered in future videos and post when we learn to achieve a Correct Creative Exposure.
Be aware of one drawback when using slow Shutter Speed: The Blur.When slowing down the shutter, you may notice some blur in your exposure. This is normal, and your camera is certainly not to be blamed for it. This statement is based on two assumptions:
- You are either hand holding your camera
- Or you are on a tripod, but you have left the Lens Image Stabilisation turned on.