How can Sigma make sure the FFF is the best success it can be? Locked

Scottelly wrote:

D Cox wrote:

Scottelly wrote:

D Cox wrote:

Iain G Foulds wrote:

… Thinking that it is important to remember that “full frame” is a false label. It is not an objective measure of completeness- as if anything smaller is incomplete.

… It is simply an arbitrary dimension and ratio left-over from film days.

It made sense when half frame film cameras were popular. Now that half frame is for some reason called APS-C it makes less sense.

If you don't like it, why not type "24x36mm" ?

And as for 4/3 --- 4/3 of what ?

Don

After posting more than 32,000 times I would think you'd have learned that micro-4/3 stands for a 2x crop factor sensor with a 4x3 format, rather than 3x2, like APS-C and full-frame cameras have. Of course, full-frame refers to a frame of 35mm film, but the sensors are actually approximately 36mm.

Or does it stand for 4/3 of a 1 and 1/3 inch vidicon tube ?

The names of sensor sizes are designed to be as confusing as possible.

Don

No. They're not. They're typically named to make sense. Micro-four-thirds is descriptive. The sensor is small, and it's basically the same as the sensor in the four-thirds cameras, which were small 4:3 format cameras that had a common image circle with old high-end video cameras (C mount). Interestingly, old 16mm movie camera lenses and C mount lenses apparently work well with m4/3 format. It seems m4/3 is one of the best "large sensor" digital formats.

No they are not named to make sense. The common sensor sizes that are measured in inches are named after obsolete Vidicon tube sizes. For example, 2/3", 1", 4/3".

None of the cmos sensors currently in use have any dimensions remotely connected to these measurements. For example 4/3" = 1 1/3 inches or c. 33mm. A 4/3" sensor is 17x13mm. The same naming madness applies to the other Vidicon standards.

The m4/3 standard name tells you it's a 4:3 aspect ratio. The "micro" bit doesn't mean it is small, it means it has a reduced flange distance compared to the original 4/3 standard. m4/3 also abandoned the telecentric requirement of the original 4/3 standard but that is not discernible from the name. So the name is really a marketing term, not a descriptive term.

Now let's look at the other other ILC common sensor sizes:

Advanced photo system (Advantix)

1. APS-C. The frame size was 25.1 × 16.7mm.

Digital half frame: Nikon's DX format is 24mm x 16, Canon's 22 x 15. Neither really matches the APS_C size, although they are similar.

2. APS-H. This was c. 30 x 17mm, a 6:9 aspect ratio. Canon's APS-H format is c. 28 x 19mm (3:2), Sigma's APS-H is 26.7 x 17.9mm, smaller again.

These sensor size names are marketing terms that don't provide much descriptive power.

So called "Full frame" sensors are the same size as the 135/35mm film format (36x24) so why not call it by its proper names rather than invent a meaningless new name that tells you nothing other than making you feel good that you have the whole frame rather than a small part of it?

Medium format film is all based around the dimensions of 120 roll film.  645 film is around 52x42mm (different camera vendors vary this slightly). Phase One's sensor is 53x40 so not a precise match for 645.   Fuji/hassie/pentax medium format is 44x33 which has nothing to do with 645, the smallest film medium format.  I would say that the Pentax 645 system which uses bodies and lenses designed for true 645 could be called a "crop" sensor system because the sensor is smaller than the body/lenses were designed for.  But Pentax did start developing a couple of lenses that had 44x33 coverage only, smaller than the legacy film lenses, so it is not a crop sensor when used with these lenses.  Fuji and Hassie build lens systems designed for the sensor size so their systems can't be called cropped sensor IMO.

Main lesson from all of this is that the nomenclature around digital sensor is a pig's breakfast and desperately needs rationalising to make sense. Which will not happen of course, as language takes on a life of its own and can't easily be controlled.