George Knight was working as an ironmonger and philosophical instrument maker from 1822 until 1861 at Foster Lane, London, and as George Knight & Sons from 1839 to 1877 at various addresses in Foster Lane and from 1877 at St Bride Street, London. From 1862 the business was continued by James How.

The firm was one of the earliest to deal in photographic equipment and chemicals from the early 1840s.