Shutter Speed

Of the three attributes of the camera used to obtain a correct exposure, shutter speed is perhaps the one that can really catch you out.  In this respect if you remember the F-Stop and ISO are the other attributes that play a role in getting the right exposure.

The function of setting the shutter speed is to: freeze moving objects, accentuate the movement of an object, give more time for the light to hit the sensor or allow less time for the light to hit the sensor.

I have taken a couple of shots below, which although they do not quite freeze the movement it does give you an idea of what the shutter speed will do.

The image above was taken using the following settings: F4.5, 1/60sec and ISO 800.  I shot this without flash and took a meter reading of the ambient light to obtain the correct exposure.  So what does this mean, well at 1/60sec you can see that the rotor blades are moving as they are blurred.  I bumped up the ISO (sensitivity of the sensor) and opened up the F-stop(hole) to let more light in.  The camera was on a tripod and I used a remote shutter release to take the picture.

 

In this image the settings were: F2.8, 1/160sec and ISO 800.  I compensated the increased shutter speed by opening up the aperture to 2.8, allowing more light in.  Although I have not frozen the movement you can see more clearly the rotor blades.   In order to capture the blades clearly (apart from not spinning them in the first place) I could introduce more light by either using flash or increase the ISO thereby making the sensor more sensitive.  I would then be able to increase the shutter speed to freeze the blades.

Things to think about when doing this: you may not see this clearly but the first image will have a greater depth of field, more of it is in focus because the aperture is smaller.  You will have to trade off between depth of field and shutter speed in this case but you can also trade off between graining or noise (quality of the image) by adjusting ISO settings, higher being less quality.  It all depends upon what it is you are trying to capture.

The last thing to keep in mind is that as you get to 1/60sec and below then you might experience camera shake.  You can overcome this by using a tripod and remote shutter release or resting the camera on something and using the timer feature that most cameras have.  Some lenses have image stabilisers and if you have a steady hand then maybe you can get away with hand holding the camera at slower speeds.  I used to be happy to hold the camera at 1/5sec but that was bracing myself against a wall or some other solid object.