Many prosumer cameras let you set shutter speed and gain. These are options for special effects and extreme lighting conditions, but be prepared for the consequence: If you crank up the gain, your footage can end up looking grainy or lack color and contrast. Slowing down your shutter speed can make motion look jerky.
If you're stuck without lights, shooting in a very dark situation, infrared settings can help. The footage will come out greenish, but you can change it to black-and-white or sepia tones during post-production (and you'll actually be able to see what's happening).
Image stabilization can make video look fuzzy or out of focus. It also requires more keyframes during encoding, increasing file size of the resulting video. Make sure that you can turn it off when you're shooting from a tripod. Optical image stabilization, built into more advanced cameras, is superior to digital image stabilization.
Inputs and Connectors
Study spec sheets for the inputs and outputs you need. Typically prosumer cameras will include mini microphone inputs and headphone outputs, FireWire, USB, and a LANC input for a zoom controller. Additional connectors you may need include A/V composite video connectors and mini-HDMI outputs.
HD or SD
If you're buying a new camera, it will shoot in some flavor of HD. Popular formats for hard-drive cameras include MPEG-2 and MPEG-4. Most prosumer tape cameras use mini-DV tapes. Editing in HD can slow output to the Web, so most high-definition cameras let you output DV when you need it, and archive HD-quality footage.
State-of-the-art flash memory camcorders trump earlier versions with costly memory cards. Look for combination cameras for flexibility. Some models include mini-DV tape and flash memory, or opt for hard drive plus flash memory, or two flash memory slots. Flash memory comes rated for speed. Faster is better.
Bigger is better. One of the biggest indicators of image quality is the size of the sensor that records your video. Current prosumer cameras typically sport 1/4-inch to 1/3-inch CMOS sensors. Some older cameras and some professional cameras use CCD sensors.