Dance Photography

(... and indoor action photography in general)

Compact snapshot	Crop from same picture

What's wrong with this picture? On the plus side, it captures a lot of smiles and has a sense of motion. On the minus side are some technical and artistic problems:

• Subject Motion Blur: the shutter speed for this picture was 1/60 sec.; during this time the dancers moved enough that their features are blurred.
• Camera Shake: also during the 1/60 sec. that the shutter was open, the photographer moved the camera very slightly. You can see this in the hinges on the door: they aren't moving, but they aren't sharp.
• Noise (Grain): In the cropped photo you can see the background is not smooth; there is what people used to call "graininess" in the days of film and now call "noise".
• Exposure: The photo is rather dark. Darkness can be used to set a mood, but this photo seems to have a happy mood, which suggests a lighter image.
• Color Balance: The color is off; there is a beige-yellow color cast.
• Dynamic Range: The black leotards all blend together; we can't see any detail.
• Composition: The photo is confusing: is the subject the foreground dancer in red? If so, why is her head missing? Or is the subject the photographer's daughter in the background? If so, why is she partially hidden? The trophies in the background are also distracting.

		(Note: you can click on any image on this page to see a larger version. (You might want to open in a new tab.) You then have the option of the "info" or "sizes" buttons in the lower right.)
Edited for brightness (exposure), color, noise	Crop from same picture

Better, but unfortunately, most of the flaws remain.

3: Basic Equipment

• Sensor area: "Photography" means "drawing with light", and ultimately what matters is the quality and quantity of light you can capture. A digital camera uses an image sensor to convert light into a digital signal. The bigger the sensor, the more light that can be gathered, and the better the image (other things being equal, and in situations, like a darkish indoor theatre, where the amount of light matters). The diagram at left below compares sensor areas of various cameras (magnified to about 4 times actual size):

  Sensor areas	Compact vs. DSLR

  The big pink rectangle represents the relative size of 35mm film (and a few high-end DSLRs called "full-frame" cameras). Most DSLRs have a sensor the size of the blue rectangle (called "APS-C," or you could call it "half-frame") while most compact cameras have sensors the size of the small purple rectangle (about 1/20 of full-frame). There are a few other common sizes in between, and cell phones have the smallest sensors of all (the teal rectagle). Note: another measure of sensor "size" is the number of megapixels. Ignore this number; all current cameras have plenty of pixels. You won't be able to tell the difference between a 20 MP and a 24 MP camera with the same sensor area. You will be able to tell that half-frame is better than 1/20 frame. Here is the same information in table form:

  Type	Example Cameras	W x H (mm)	Area (mm)	Percent	Ratio
  Full-frame	Canon 5D; Nikon D800	36 x 24	864	100%	1/1
  APS-C	Canon T4i; Nikon D7000	23.6 x 15.7	370	43%	1/2
  4/3	OMD-EM5; Panasonic GH4	17.3 x 13	225	26%	1/4
  1 inch	Sony RX100; Canon G7 X	13.2 x 8.8	116	13%	1/8
  1/1.7 inch	Canon S110; Panasonic LF1	7.6 x 5.7	43	5%	1/20
  Cell phone	IPhone 5S	4.8 x 3.5	17	2%	1/50

• Interchangable lenses: in buying a DSLR you don't just buy the camera, you buy into a whole system. You can add lenses that are designed for specific purposes (such as portraits of moving subjects in low light). For dance I recommend a lens with a maximum aperture of f/2.8 (or even better f/2 or f/1.8). A wider aperture gathers more light, enabling you to shoot at a faster shutter speed, and thus is called a "fast" lens. They tend to be more expensive, but needn't break the bank; a 50mm f/1.8 lens is about $100.
• Viewfinder, focus, and shutter lag: By definition, "SLR" means that the light comes through the lens, hits a mirror, and is reflected to your eye. That means you see what is actually happening, without the delay that can occur with an electronic LCD display. In addition the autofocus mechanism of an SLR is faster than for compacts, and there is almost no lag from the time you press the shutter to when the picture is actually taken. This makes DSLRs better for photographing action.
• Controls: DSLRs are bigger than compact cameras, so there is more room to put physical controls (dials or joysticks) that allow you to instantly adjust your camera's focus point and exposure, rather than having to go through a complex menu system.

If you've bought a DSLR in the past few years, congratulations--no matter what model you have it is certainly capable of taking great pictures. If you are currently agonizing over what model to buy, don't worry, you can't go wrong; all the DSLR cameras offered today are good compared to just a few years ago. When in doubt buy the same model that your friends have, so you can share experiences.

4: Types of Blur

After I said "Oh crap--my pictures are all fuzzy/blurry," my next step was to diagnosis the cause of the blur--you can't correct a problem if you don't know what the problem is. Here are the five most common types, and how to tell them apart:

• Subject motion blur: if a motionless part of the picture (the background, or some part of a dancer's body like a foot planted on the ground) is sharp but other parts are not sharp, you've got subject motion blur. In the "King at 1/6" photo below, the King is standing in the wings. It is very dark, necessitating a shutter speed of 1/6 second. It looks like the King is standing perfectly still, so does that mean the problem is camera shake? No--we can tell it is subject motion because the edge of the purple wall beside the King is very sharp. The wall stayed still; therefore the camera stayed still and the King moved.

  King at 1/6: Subject motion	Pan at 1/40: camera motion

• Camera shake/motion: if everything is blurred (and the closer things more so than the distant ones), that suggests the camera moved during the exposure. In the "Pan at 1/40" picture above, we can tell the camera is moving because the background is not sharp, nor is the boy standing at attention. The camera does a pretty good job of panning with the running dancer at left, but that means the two dancers in the background, who are running in the opposite direction, are doubly blurred (subject motion plus camera motion).

• Misplaced plane of focus: In the photo labeled "Misfocus" below, the camera's autofocus system locked on the dancer in the second row, leaving the dancer in the foreground out of focus.

  Misfocus	Crop of Misfocus

• Noise: Sometimes there is no motion blur, focus is spot-on, but digital noise steals away all the detail. The image labeled "Noise at ISO 1600" is an example of this. (At a shutter speed of 1/40, subject motion is also a contributing factor.) This image was taken with an older generation of camera (2003). Nowadays, most cameras do much better with noise, so this will be less of a problem for you.

  Noise at ISO 1600	Crop of Noise at ISO 1600

• Concept: Ansel Adams said "There is nothing worse than a brilliant image of a fuzzy concept." And indeed, if you don't have a good idea of what you are trying to show, and know how to compose the shot, the concept will be fuzzy even if the details are sharp. The first picture on this page suffers from fuzzy concept (along with all the other flaws).

On the next page we take a detailed look at the types of blur, and at the basics of exposure.