Ever since the 35mm small frame gained popularity in the mid-1900s it's well known (and perhaps lamented) the particular crop factor became a de-facto standard by late 1900s when people discussed their fields of view, a useful thing when talking about compositions, compression and other related things.

Nowadays one can say he's got a "35mm lens" when he means he bought a micro-4/3 lens with a focal length of 17mm. Perhaps not technically correct but as a "standard" the 35mm equivalency gets the point home. You know what kind of a field of view a 35mm lens sports.

How were these coffee machine conversations back then, before 35mm took over the world?

Was it just like "well I have this here lens says 200 mm on the side and it makes a mighty good portrait" and that be the end of that? :)

  • I guess (being the operative word) that in the days before 35mm film, cameras were precision tools owned and used by "real" enthusiasts and/or quite technical people. Maybe by mentioning a focal length and a format, the approximate angle of view could easily be deduced, without any need for a layman's conversion system.
    – osullic
    Jan 9, 2019 at 9:15
  • 1
    "Coffee machine conversation"...don't you mean, watching progo grind the coffee while Hueco get's the fire started so we can all sit around and wait for the coffee to percolate? :-D
    – OnBreak.
    Jan 9, 2019 at 16:54

3 Answers 3


We did not worry about making comparisons between formats, as there was no dominant format size. We spoke about angle of view by citing the published degrees. As an example, a Rollieflex 120 film size with an 80mm focal length delivered a 60° angle of view. We were satisfied by that, however, in the jargon of photography, then and now, this quoted value is the diagonal (corner-to-corner) measure. I think this is odd, like selling TV’s by their diagonal measure. Actually, the above lash-up delivers a 41° angle of view both horizontal and vertical, because the format is a square 60mm by 60mm.


Back then folks, for the most part, were not so obsessed with exactness and precision. Most of the time "wide angle", "normal", or "telephoto" was descriptive enough for most purposes.

Before the 135 format rose to dominance, there was no real expectation of expressing angles of view in terms of millimeters of focal length.

  • Sometimes I think folks back then were more obsessed about technology and advancing it than we are today...
    – mike3996
    Jan 9, 2019 at 13:36
  • They were certainly obsessed with "advancing technology" at times. I'm not so sure they were as obsessed with being more verbally precise about the minutiae of the numerical aspects of a new technology when discussing it.
    – Michael C
    Jan 9, 2019 at 14:22
  • Perhaps so. Certainly photography became a nasty numbers game (for many) after digitalization...
    – mike3996
    Jan 9, 2019 at 14:38
  • 1
    @progo wide angle lenses were especially difficult in the beginning. Try explaining this one using just mm's...earlyphotography.co.uk/site/entry_L129.html
    – OnBreak.
    Jan 9, 2019 at 17:00

(How) were FoVs discussed before the 35mm became de-facto standard?

It was discussed similarly to how it is today. Focal length is in some distance metric, like mm. Field of view is in degrees. Some old lenses have the field of view marked on them, in addition to the focal length.

Nowadays one can say he's got a "35mm lens" when he means he bought a micro-4/3 lens with a focal length of 17mm.

A 35mm lens is a 35mm lens no matter what the format is. If someone says that he has the equivalent of a 35mm lens, it might refer to a 17mm lens for MFT because it's assumed that "equivalent" refers to the ubiquitous 35mm film format. It could also refer to a 24mm lens for APS-C. But saying "35mm lens", without the use of the word "equivalent", refers to an actual 35mm lens. Another example is the standard MFT kit lens, which is 14-42mm. No one calls it a 28-84mm lens because it isn't.

When we discuss lens focal lengths, it is with respect to a particular format or sensor size. We do not assume it refers to a 35mm film frame. That is why you'll often see a comment asking about the camera model or sensor size when someone asks for a good focal length to use for some task.

Once you know the film format or sensor size, you can calculate the length of the diagonal to use as a reference, the "normal" focal length. For full frame, it's about 43mm (50mm is close enough). For APS-C, it's about 29mm (35mm is close enough).

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