Originally posted by Class A It is not worthless because "full frame" mainly means that the sensor is not artificially smaller than what the mount was designed for.
The K-mount was designed for a 36mm x 24mm frame but due to cost reasons, APS-C DSLRs only use 24mm x 16mm of this frame. They crop, i.e., they don't use the full frame.
The fact that "full frame" is typically associated with the 135 format (36mm x 24mm) is less useful, although defensible because this format size has been vastly more popular than any of the larger ones.
You cannot make such statements that the 135 format was vastly more popular than any other format. It just isn't true and its indefensible. It was very popular for a short period that's all.
Lets put it into some perspective with some history.
Until Kodak came along the only camera formats were huge compared to the humble 135, The entire world was equipped with large format daguerreotype calotype tintype wetplate dry plate etc etc.
Millions upon millions of cameras were sold in those sizes.
Later Kodak marketed the brownie 6x6cm roll film, this took over as the most popular format size. Kodak equipped the world with roll film cameras, were talking millions upon millions of cameras possibly running into hundreds of millions, One single model of brownie alone sold over 10 million units, and there were many other models of brownie sold.
All in all an unspeakable number of 6x6 roll film cameras were sold world wide, far outstripping the puny sales of 35mm cameras by comparison. Every household in the world it seemed had a brownie, in my own family we had 3 box brownies, and 3 other 6x6 roll film cameras as well. My first camera was a roll film 6x6 cm camera. I have owned more roll film cameras than I have 35mm cameras, in 645, 6x6, 6x7, and 6x9 formats. Box cameras folding cameras and TLRs.
Sure 35mm cameras sold in huge numbers, but only between 1965 and 1995. Before 1965, roll film cameras held their own in volume sales, and after 1995 digital cameras ate into the 35mm market share.
Can we stop trying to justify calling the tiny 35mm camera "Full Frame" there really isn't any justification. 35mm was always a miniature camera format, and in my view it still is.
I am not suggesting that this miniature format cannot produce excellent images, I just cannot accept that a format that is a mere 5% of the size of a studio camera format can be in any way described as "Full Frame"
Only in photography is this somehow acceptable, would you call a 308mm cartridge, a 300, a 7.62mm a 5.56 mm or a .50 cartridge "standard" and a 0.22 "Full Size".
Would you accept that a 350 cu inch v8 and a 455 cu inch v8 are "standard" engines and a 200 cu inch is a "Full Size" engine.
Would 20,000 dollars 40,000 dollars and 80,000 dollars be "standard pay" and 5,000 dollars "Full Pay"
Its time to call a horse a horse and abandon this misleading name.