Your 'favourite' FOV

AlbertInFrance wrote:

primeone wrote:

The 80mm "normal" lens on a 6x6 is slightly "wide" (6x6 diagonal is about 85mm, so an 85mm lens would be "normal") This would be roughly translate to a 6% move in the wide direction.

Sorry to put a spanner in the works, but you are missing a couple of factors here.

6x6 is nominal. The frame is actually 56mm square, giving an 80mm diagonal to the nearest mm.

More significant is the fact that hardly anybody actually printed square, but rectangular. This is why '645' became popular once pentaprisms became economically available for medium format.

That results in a 70mm useful diagonal, so an 80mm is actually pretty similar in that respect to 50mm on a 24x36mm frame.

50mm lens on FF is slightly "long" (24x36 diagonal is about 43mm, so 43mm would be "normal").

Funny enough, the fixed prime on my first 35mm camera was a 45mm rather than a 50. I still find 27mm on APS-C (OK, a touch wider) more comfortable as a family shooting lens than a 35mm.

A 50mm FF is roughly 15% "longer" than normal, in some cases even more, as many 50mm lenses are actually longer in true Focal Length.

See above.

Albert:

Not really a "spanner" (or wrench, as "yanks" might say), but at most a "nit".

The brief history of 6x4.5 is interesting, but not really relevant as the post I replied to was referencing "normal" 6x6 as a point of reference and comparison and point of departure for "equivalence".

I'll accept 80mm diagonal as a correction, which is almost exactly the MFT 20mm FOV.  The poster I replied to was still comparing two different "equivalent" Focal Lengths, and trying to use an incorrect extrapolation of DOF as a result.  80mm 6x6 FOV is still not 50mm 24x36 FOV, if is wider!

Back in the glory days of  "35mm" it was almost always cropped as well, as 24x36 did not fill an 8x10 sheet of paper, which resulted in the left and right ends of the negative being lost, resulting in a "longer" feeling FOV.

I hate to generalize, but I will: almost everything we view is cropped, with the exception of cell phone quickies, Large Format, and "do these corners look sharp to you" postings in forums.

I have always loved the 35mm on FF FOV, and adapted to the somewhat narrower 40mm FOV, which is slightly more versatile.  I have used the fine Lumix 20mm on MFT and equally fine 27mm Fuji on APS-C as well as the outstanding 40mm Summicron on Leica CL.

I have also owned and used several fixed lens 35mm cameras with lenses from 35mm to 42mm.  None of these lenses, however, would be touted as "nifty fifties".

As to fifties being 50mm, I know that many Summicron 50s can be examined internally, to expose bench engravings/scratching allowing them to be matched with focussing mounts to a lens cell based on FL.  51.5mm to 52mm is what is typically found!  That is closer to 20% longer than "true normal" 43mm!