Telephoto Lenses and Human Vision

Discussion in 'Adapted Lenses' started by dabbler, Jun 4, 2011.

  1. dabbler

    dabbler Mu-43 Regular

    131
    Feb 5, 2011
    I wonder if you could help with my investigations about telephoto lenses? I've often read that 12mm focal length (on m43 sensors) is the low limit for vaguely normal-looking pictures, lower than which human vision and the lens optics diverge substantially. I presume there is a similar point on the telephoto side, beyond which the perspective looks unnatural. If so, is there a commonly-agreed focal length for this limit?

    My purposes for asking are firstly that I'd like a prime lens that can juxtapose foreground and background objects without the ordinary viewer having a distracting sensation that something strange is going on with the optics; and secondly that I'd like a lens that can 'pump up' flat but interesting land between myself and the horizon, (e.g. a flower-filled meadow) so as to make the flat land more prominent in the photo. Hopefully those uses are compatible?

    I know that online there are vast numbers of telephoto pics tagged with their focal lengths, but particularly for the second purpose it's difficult to judge accurately the degree of 'lift' without knowing how flat the land was in the first place! I hope to experiment with a range of inexpensive, compact adapted lenses, and having an idea about an 'upper limit' for natural telephoto pictures would greatly help me find a focal length that I'm happy with for these needs. I hope you can help!
     
  2. Pan Korop

    Pan Korop Mu-43 Veteran

    479
    Mar 31, 2011
    Phare Ouest
    Why don't you try first with one of the excellent, but unexpensive, stock Pan or Oly zooms? For instance, a 45-200 Pan would certainly let you try all usual telephoto angles.

    As for "natural" perspectives, you could hardly go wrong with a standard zoom, i.e. like the Pan 14-45mm. Little distortion at one end, no big compression at the other.

    Except, of course, if you take the wide-angle shots in ant-eye's view and the telephoto side in bird's eye: "Natural" perspective is not as much a question of focal length, as the way normal people normally look at usual scenes... As for portraits, the "naturalistic" approach hardly ever pleases the portrayed person--better get a model relaease before publishing :biggrin:
     
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  3. dabbler

    dabbler Mu-43 Regular

    131
    Feb 5, 2011
    Thanks for your response Pan Korop! I was thinking about staying with primes as I fear I might start using zooms for framing, but I'll definitely check out the 45-200 Panasonic for my GF1.

    I hear only good things about the 14-45. I'm just wondering if I could 'get away' with using a longer focal length than 45mm, if that's not quite long enough for portraits- I guess our eyes are more sensitive to small changes in the human face than to pretty much anything else, and if the results of a longer focal length can be accepted as being faithful representations of a human face...

    Well, I'll experiment, and the 45-200mm might be a good way to do that. Cheers!
     
  4. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    Yes, when you go to longer focal lengths in portraits, it only makes a more flattering view by compressing the perspective. My favorite portrait lens is my Zuiko 50-200mm SWD, when I have room to use it. 200mm is excellent for headshots when given enough space. 85mm f/1.8 primes are also great portrait tools.
     
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  5. Don't get too hung up on avoiding zoom lenses, as though someone else might think they are a less "pure" form of photography. From that point of view, all of our modern cameras are tainted by technological advances of some form or another. I find zooms to be convenient as much as I find auto exposure to be convenient.
     
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  6. dabbler

    dabbler Mu-43 Regular

    131
    Feb 5, 2011
    Ned, so you can get accepted-as-faithful portraits at 200mm? Interesting, maybe we're less sensitive to perspective compression than I imagined.. It still surprises me that the 'classic portrait focal lengths' are rather longer than 'normal focal lengths'- I'd have thought our facial features would have evolved to look at their best to the human eye's optics, or vice versa. Ah well, nothing that can't be solved by beer.. 'Beergoggles: See life as Nature intended (but hasn't quite yet accomplished)':wink:

    Thanks for the advice, Luckypenguin! I hope I don't/won't fall into that trap, though to be honest I'm not quite sure what 'pure photography' could really mean! I also have the greatest difficulty distinguishing between prime lens images and zoom lens images at the identical focal length. And I'm sure I'll get at least one zoom before too long.

    At the moment, though, I think that my framing and pre-visualisation might be *best* improved by sticking to prime lenses that have ideal focal lengths for expected situations, and learning those focal lengths inside out. Hence my interest in primes! Using a zoom lens in order to find preferred primes, or indeed just using a zoom lens, are also approaches worth exploring, though (in my novice opinion!)
     
  7. ~tc~

    ~tc~ Mu-43 Hall of Famer

    Oct 22, 2010
    Houston, TX
    I may be misunderstanding what you are trying to do here, because it seems to me that an extreme wide angle, or even a fisheye would be the desired tool here. Aiming/composition will be critical to ensure whatever distortion the lens creates accentuates the mood you're after, not detracts from it.
     
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  8. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    The only time I worry much about perspective distortion is at wider angles. I generally use telephoto lengths to avoid that. ;)
     
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  9. dabbler

    dabbler Mu-43 Regular

    131
    Feb 5, 2011
    ~tc~, I think 'pump up' may have been too vague, so I'll let Michael Freeman explain it as he's more articulate than I am!

    "A specific practical use [of a telephoto] is to give some height to an oblique view of level ground... [A] telephoto lens from a distance gives the impression of tilting the surface upwards..." (Photographer's Eye, p. 102.)

    As I understand it, a wide angle gives the foreground width; a telephoto gives it height. It's the vertical distortion and the ability to juxtapose that particularly interest me.

    I've no idea about fish-eyes- haven't investigated as they just look a bit too freaky for me!

    Regarding perspective, perhaps I should learn from Ned - worry less, shoot more!:cool: