Evaluation and adaptation of a non-single-lens reflex camera for users with manual impairments
The accessibility of consumer products is an issue for many people with special needs. This study addresses the usability of non-single-lens reflex (NSLR) cameras for people with limited hand grip strength and finger dexterity, namely people with quadriplegia or people with arthritis. It proposes a three-phase methodology to eliminate or mitigate accessibility barriers on a consumer product.
A usability test was conducted with a NSLR camera. Problems were recorded with the Critical Incident technique. Prioritization of the problems reported by the subjects show that the shutter release control and the camera grip are the two major accessibility barriers of the product.
Four new camera models were developed: three with gripping aids (rubber pads, a thumbsleeve, or a handle) and one with a remote wired shutter release control. A fifth model was obtained by combining the remote shutter release control and the handle.
A designed experiment was conducted with the five models and the standard camera. Performance measurements of framing tilt and camera shake were collected, as well as subjective opinions. Results indicate a recurrent difference between performances of quadriplegics and performances of other subjects. The remote shutter release control was shown to eliminate accessibility barriers. The handle also increased ease of grip and camera stability for disabled subjects.