Flying Turtle
Flashaholic
Sorry to be starting yet another oldest LED thread, but I couldn't resist. I can't recall when LEDs started showing up in commercial products. Certainly flashlight use is relatively recent, but instrument use goes farther back. It dawned on me the other day that I've been sitting on an LED application that dates to 1972. I haven't used it in a few years, so it slipped my mind.
In 1974 I purchased my first, and only, SLR camera. After much research I had narrowed my search down to the Olympus OM-1 and the Fujica ST-801. I decided on the Fujica for a few reasons. It was a bit cheaper, had screw mount lenses (bad advice from a teacher), and had a somewhat revolutionary metering system. Instead of the CdS meters of other cameras, the Fujica employed a silicon photodiode which was much faster. And instead of the match needle meter in the viewfinder it used seven tiny red LEDs to indicate the correct exposure. Just adjust aperture and shutter speed to get the center LED to light. This system worked quite well, giving fast readings that were easily visible. Fuji followed this camera, which was first sold in 1972, with an auto model (ST-901) that also used LEDs to indicate the chosen shutter speed. This is the first example of LED use that I was familiar with. Can't believe I didn't think of it before.
Geoff
In 1974 I purchased my first, and only, SLR camera. After much research I had narrowed my search down to the Olympus OM-1 and the Fujica ST-801. I decided on the Fujica for a few reasons. It was a bit cheaper, had screw mount lenses (bad advice from a teacher), and had a somewhat revolutionary metering system. Instead of the CdS meters of other cameras, the Fujica employed a silicon photodiode which was much faster. And instead of the match needle meter in the viewfinder it used seven tiny red LEDs to indicate the correct exposure. Just adjust aperture and shutter speed to get the center LED to light. This system worked quite well, giving fast readings that were easily visible. Fuji followed this camera, which was first sold in 1972, with an auto model (ST-901) that also used LEDs to indicate the chosen shutter speed. This is the first example of LED use that I was familiar with. Can't believe I didn't think of it before.
Geoff