The picture above is a sample of a long shutter exposure. It was taken with 1/8th of a second with F7.1. Super Steady Shot ON, handheld. A man with his satay. A long exposure picture is a good example on to show the pathway of the fire, and also the movement of the man.
What is a long shutter exposure? Well, what is shutter anyway? ;-)
A shutter is just like a window blinds. If it is open, it’ll let the lights come in. If it is closed, it won’t let any light go through. The window glass is your lens. Behind the shutter is the sensor (this is only applicable for digital cameras). The sensor is very sensitive to light. When the sensor is exposed to light, it’ll draw pictures. Basically, that is how a digital camera works.
Light go through lens, through an opened shutter, exposed the sensor and produced pictures.
If your shutter opens too long, you’ll risk an over exposed picture. What is an over exposed picture? A picture which looks too bright, lost details on most of the subject, and worst case, it went white. If your shutter opens too short, you’ll risk under exposed picture. A totally opposite of the overexposed, still not that much details captured, and worst case, it went black.
But, how can I create a nice long shutter exposure by not risking my picture to get overexposed?
Not that hard. Remember the basic principal of window & blinds? Yes? Good. Actually there are one more thing to that basic. It is the aperture. It is basically the opening diameter of the lens blades. Means, in other words, between your blinds and your window glass, there are another blinds that are adjustable on the amount of light allowed to come in.
In simpler noob calculation, if a perfect picture (P) is 100% consist of 50% (S) shutter opening and 50% (F) diameter of aperture
100% P = 50% S + 50% F
If you still want a perfect P but with higher (& longer) S, you’ll have to minus the F:
100% P = 70% S + 30% F
And vice versa.
BUT in photography, a smaller F means that a bigger in F numbering format. For example, F2.8 aperture is bigger than F16 aperture. I think you’ll get confused with it. Ok, example below:
100% P = 1/125 S + F2.8
OR
100% P = 1/4 S + F16
In example 1, a higher S is needed to get a perfect picture, but your Aperture has to opened big enough to let the light come in through. In example 2, a slower S is needed to let more lights come in because the Aperture is small (not that many lights allowed to go through the lens as the aperture opening is small).
Slower S means that your camera has to be that steady and should not move at all to let the picture evenly formed. If else, you’ll result in ‘shaking’ picture. And if you purposely want a shaking picture, just don’t put your camera on tripod~ ;-) Take long shutter picture while jumping, then you’ll get it. Happy shooting Long Shutter Exposure pics!
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