Until the release of the Nikonos IV-A in 1980, a waterproof light meter was essential for divers wanting accurate exposures.

Nikon produced the ‘Watertight Exposure-Meter Case’ for use with the Sekonic Auto Lumi L-86.

Other companies produced underwater exposure meters and/or housings, many became synonymous with the Calypso and Nikonos cameras. The following are a few of the more collectable models.