Relying on a Shutter speed slower than one that would freeze the moving subject in timeWe saw in the episode The Shutter that if one wants to capture a still situation without any camera shake, there is a rule of Thumb: The Shutter speed= 1/Focal length (35mm sensor equivalent). Meaning: If you are using a Focal lens length of 18mm on an APS-C ( Advanced Photo System type-C) cropped sensor camera (Here a Canon 1.6x ration): (1.6×18) = 28.8 so your shutter speed should not be faster 1/28.8 sec. While this rule is for still situations, it is a good indicator for Panning photography as well. Note you could (depending on your distance to the subject) freeze a moving formula1 car with a Shutter speed of 1/800, but when you do Panning photography, you could still use a Shutter speed 3x slower like 1/200. The next point will explain why.
Focus and take the Exposure while following the moving subjectThis chapter is the key factor to obtain a Correct Creative Exposure (to not be mistaken for a Correct Exposure). While the Shutter is slower than normal, you need to compensate the lack of speed by accompanying the moving subject in its trajectory. This is crucial to enable you to keep your subject in sharp focus. The Creativity is a consequence of this. Since you are moving while taking the shot, the background and foreground, anything that is not on the same line of focus as your subject is bound to be blurred out. While this sounds easy when you read the above, in practice it can be tricky depending on whether your camera offers you some interesting features:
Continuous FocusMost DSLR if not all would have a Continuous Focusing Mode whether it is called AIServo on Canon or Continuous on Nikon and others. This Mode enables you to keep focusing (as you press half way the Shutter button)while your subject is moving, the lens adjusts itself as the distance between it and the subject changes. Note if your camera does not offer this Mode, you can then decide where in the scene you will be taking the exposure and focus then lock it until your subject enters the scene and reach that chosen position.
Spot FocusingMost DSLR if not all enable you to choose a specific focus point in your viewfinder. This is a good feature as otherwise, the camera would decide for you what should be in focus and we know by know how much your camera lacks a brain and therefore creativity. I prefer the middle spot since it is easier to frame the situation. You can always recompense in post-production anyway by cropping (with moderation).
Continuous DriveThis is a nice feature to use, as it enables you to capture exposure at a very high-speed pace. My Canon 60D offers 5.3 frame per second which is not the highest one can get from a DSLR (i.e professionals) but more than enough in most situations. Shooting a moving subject by definition is meant to be fast and trying to capture it in 1 single exposure is surely a challenge I can spare myself.
Step by Step
- Choose the Exposure mode you want to use; it needs to be either The Shutter Priority mode or the Manual one. Set you Shutter speed to a starting base such as 1/30. You can always change it afterwards if it is either too slow or too fast. Note that if you are shooting Formula1 or plane, then you can jump to 1/200 as a starting value.
- Assess the situation and more specifically its brightness. Take a sample exposure and adjust adequately (see Correct Exposure if needed):
The distance of the subject from you impacts the notion of speed. Farther the subject slower it appears to move and in the shot below you can see that 1/50 is too fast for the distance more than one horse is in focus, and the background/foreground is not that blurred out.
But keeping the same Shutter speed as the horses get closer to me, the leading horse is in focus, the others are blurred out, and so are the background and foreground.As the racers get even closer to me, the blur increases where needed and the leading horse appears to go fast. This last exposure is a good illustration of what the Creative Shutter offers to imply motion. As a side note, although I have not used any tripod for these shots one can use a monopod to add vertical stability in the panning movement. I did however use the Image Stabiliser of my lens not that I can prove it had any benefits but I like to think it has since it is meant to reduce the vertical shake as well.