Beseler Topcon Super D
A very significant development for the evolution of 35mm SLRs, Tokyo Kogaku (Topcon) introduced true through-the-lens (TTL) exposure metering in its model the Topcon RE Super. For distribution in the USA, importer Charles Beseler (the enlarger company) changed this model's branding to Topcon Super D.
Confusingly, when Tokyo Kogaku updated this model in 1971, they gave the new model the designation Super D worldwide.
The TTL method was ingenious, with a pattern of fine lines on the reflex mirror without silvering which allowed light to pass through to metering cells behind. While this robbed a tiny amount of light from the finder image, the lines themselves were out of focus and undetectable. This approach was favored by Topcon as they wished to preserve one of their key selling points, the interchangeability of viewfinders.
Beseler Topcon Super D
A very significant development for the evolution of 35mm SLRs, Tokyo Kogaku (Topcon) introduced true through-the-lens (TTL) exposure metering in its model the Topcon RE Super. For distribution in the USA, importer Charles Beseler (the enlarger company) changed this model's branding to Topcon Super D.
Confusingly, when Tokyo Kogaku updated this model in 1971, they gave the new model the designation Super D worldwide.
The TTL method was ingenious, with a pattern of fine lines on the reflex mirror without silvering which allowed light to pass through to metering cells behind. While this robbed a tiny amount of light from the finder image, the lines themselves were out of focus and undetectable. This approach was favored by Topcon as they wished to preserve one of their key selling points, the interchangeability of viewfinders.