Pocket Light Meter App for iPhone
My light meter of choice for close to two decades has been the Pentax Digital Spot. My first act when setting out into the landscape to photograph with my old 4×5 view camera was invariably to hang the pistol-gripped device around my neck. It went everywhere with me, and determining exposures with it, including filter factors, reciprocity failure of film, and camera bellows extension became second nature.
Though today’s digital cameras make hand-held meters unnecessary for most landscape photography, from time to time I still encounter situations when it would be handy to be able to take a meter reading independent of the camera. Incredibly, the iPhone delivers a solution that is very practical, effective, and free!
Nuwaste Studios has developed a spectacular light meter app for iPhones. It will read down to EV -1.78 and can be used to calculate accurate exposures longer than you would ever need (hundreds of hours). It can be calibrated as well if necessary, though in comparison to both my Pentax meter and my Nikon D700, it is right on the money. The correction factor comes in really handy, however, for film users who need to account for filter factors or reciprocity failure. In addition to shutter speed and aperture, it also reads out in EV, Lux, Foot Candles, and Cine shutter speeds. If this were a stand-alone digital light meter, it would cost $200 or more.
The next time I need to do an exposure longer than 30 seconds, or if I’ve got my camera all locked down on the tripod and don’t want to move it to take an in-camera meter reading, I’ll just grab my iPhone! –Justin Black
