Cameras

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Brands

• Point Grey: these come highly recommended by John Stanley.
• Lumenera: had good luck with these in NZ.
• Allied Vision

Sensors

• Resolution - try to balance the need for detail with functionality. High-resolution can capture fine detail, but will impact image transfer speed, data storage requirements, and image processing. E.g. you'll never transfer an image cube of 12MP images through a MiFi connection.

• Type - Camera sensors typically come in two types CCD and CMOS. Traditionally CCD were higher quality (and more expensive) than CMOS, but recent improvements in CMOS technology have made them more comparable (but CMOS is still significantly cheaper).

• Size - The "size" of a camera refers to the image sensor size, usually expressed as a reference size (not physical). For example, a 1/2" sensor is not actually 1/2" wide. In general, the larger the sensor the better, since the individual pixels will be larger and collect more photons, increasing sensitivity. Also, a smaller sensor will require a smaller focal length lens to achieve the same field of view, often resulting in a need for a highly distorted fisheye lens ( fl<6mm ). However, a larger sensor requires a larger diameter lens (to prevent vignetting) which will cost more. The best way to determine the sensor size is to refer to the sensor documentation, which should report the pixel width and height. Multiply those values by the number of pixels to get the true size. In practice, sensors smaller than 1/2" should be avoided.

Camera Interface

When selecting a camera, consider which type of interface will be appropriate for your application. Speed, cable length, and computer hardware may play a role. Some common interfaces for transferring imagery are:

• GigE
• USB 3.0
• FireWire

Also, consider your need for synchronization between multiple cameras. Some cameras are easier to establish a hardware trigger which can synchronize image capture between multiple cameras. Hardware triggers send a voltage signal to the camera(s) directly and tend to have timing accuracy on the order of microseconds rather than milliseconds typically achieved through software triggers. Point Grey offers a technical document on synchronizing their cameras with hardware triggers through built-in GPIO ports that may be helpful when getting started. Other solutions for cameras that don't have dedicated ports for hardware triggers have been found by members of the community, that utilize audio channels and GPS timestamps in post-processing.