1.3x, 1.5x, 1.6x, where did it start?

[luckyrwe]

I was thinking about the EF-S lens thread here and I wondered about all the different times factors. Then I got to thinking...did the camera world not go through this back when the 35mm came out? I am sure going from 4x5 or 2 1/4 square to 35mm made many people balk. Remember 35mm was considered miniature at the time, today only Minox is miniature.

[Mitch]

I was thinking about the EF-S lens thread here and I wondered about all the different times factors. Then I got to thinking...did the camera world not go through this back when the 35mm came out? I am sure going from 4x5 or 2 1/4 square to 35mm made many people balk. Remember 35mm was considered miniature at the time, today only Minox is miniature.
Don't forget 1/2 frame 35mm.

[NHBubba]

Word has it that the 35mm format came from exposing a 24mm movie film sideways and 2 frames at a time.

I got this from this article (http://www.kenrockwell.com/tech/dx.htm) on www.kenrockwell.com:
Digital SLRs take advantage of using sensors about 16 x 24 mm, close to the original standard 35mm (movie) film standard of 18 x 24mm introduced over 100 years ago and still in daily use in Hollywood movies and TV. When minature still cameras were designed to use 35mm movie film in the 1920s they were called "double frame" and shot a double wide frame of 36 x 24 mm. This remains the size of today's 35mm film (still) cameras which are fast becoming obsolete.

Try to read through the 'DX is great, full frame blows' rhetoric and you might find some decent background there..