Scrambler
Well-known
That seems highly unlikely. How it varies, though, has not been addressed in this thread other than as theorySince the viewing distance of a print varies randomly,
Well, that's just opticsand the magical viewing distance can be recreated for various focal lengths,
If you wish to define a normal lens with reference to viewing distance and print enlargement, be my guest. It's how Roger Hicks defines it (although he uses the word "standard" rather than "normal") and how Wikipedia defines it. I have no personal axe to grind, other than that isn't how it was defined by camera manufacturers in times past.I think these effects should be ignored when determining what focal length lens is 'normal'.
The way I personally look at photos is to get the two diagonals as equal as possible.It makes sense to me that the 43mm is 'normal' for a 24x36 frame, since that's the diagonal and as we've seen the usual way to look at photos is tilted diagonally.
Look, I get that the whole "diagonal" thing gets up your nose.
If it makes you feel any better, camera manufacturers used 1.44 x the average of the height and width of the format to define their "standard" lens.
Ignore the "diagonal" thing. Ignore the word "normal."
Were the manufacturers correct? Who could say? They made the rules.
Now if, on the other hand, you want to define a lens based on the magic distance, angle of view etc, some additional data is required. So far it has been said is that people should look at images at the magic distance. Do they? It has been said the people view images from a distance equal to the image diagonal - but the evidence I can find online says it is more like twice the diagonal. What do real people looking at real images do?
And this mob reference this document to say that images representing the visual impact of adding wind turbines should be taken with a 75mm lens and printed not less than 390mm on the long side and 260mm on the short - and viewed at 300-500mm. What is remarkable is that this, unlike the 43mm or other proposed lengths, is based on science - here is a newspaper report on this. I'm still looking for the original research.
Well if you look at images tilted diagonally, you may as well ignore the whole discussion since it's not going to help your particular situation much.
PS - I know that the 75mm/390mm/500mm thing doesn't work out - the viewing point is well inside the "magic distance." But that's science for you - sometimes the experiment doesn't turn up what your theory predicts.