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Poll - Which focal length, on a full-frame camera,

Discussion in 'Weekly Poll' started by Damien_Demolder, Mar 12, 2013.

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  1. Damien_Demolder

    Damien_Demolder Well-Known Member

    would you use to create a sense of reality?

    Pentax took us by surprise in 1997 when it introduced a 43mm lens for its 35mm film SLRs. While it was (and is still) quite an expensive optic it proved to be a very good one. That it was good didn’t take us by surprise, of course, but that it had a peculiar focal length. When questioned, the Japanese optical designers explained that the angle of view of a 43mm lens matched that which the human eye can see. This, then, was the perfect tool for real-world photography. I suspect though that if we all peered through a 43mm on a full-frame camera we would disagree – we can, as a matter of fact, see an angle much wider than the 53° this focal length allows.

    But the point is of making pictures look like the reality of being in that place, with a perspective that fits what our mind would expect to see. The eye might see 180° but when you show this angle in a panorama the viewer has to scan from side to side to take it all in. What we can concentrate on, and therefore what our mind sees, is a much smaller segment of the world. So I wonder, then, what the perfect focal length is for presenting a sense of reality.

    Take part in this week's poll - Which focal length, on a full-frame camera, would you use if you wanted to create a sense of reality? by visiting the AP home page.


  2. Roger_Provins

    Roger_Provins Well-Known Member

    I always found 35mm about right and better than the ubiquitous 50mm "standard" length of film camera days.
  3. Zou

    Zou Well-Known Member

    None of those. 35mm too wide and 50mm too narrow on a 36x24mm frame, I prefer 40mm. In terms of natural looking perspective either is ok. My eyes' fov is pretty close to what my Zero 45 (25mm on 5x4") gets, but the perspective is hugely different.
  4. Zou

    Zou Well-Known Member

    Do you have a source/reference for that?
  5. beejaybee

    beejaybee Marvin

    Reality, in terms of matching perspective, around 40mm. In terms of matching field of view, a "fish eye" is necessary. In terms of matching detail in the centre of the field of view, somewhere between 135mm and 200mm - with Kodachrome 25 - a slightly shorter focal length would probably be just as effective with modern high resolution digital sensors & really good quality glass.

    IMHO the 35mm full frame compacts which came with a fixed focus lens of around 40mm focal length had the thing about right, in the days before zoom lenses were a practical proposition. 35mm "wide angle" was just a shade too wide ... though the ideal focal length / field of view was (and remains) dependent on your style and the subject matter as well as the fine detail of the technology in use.
  6. Roy5051

    Roy5051 Well-Known Member

    In the early days, around 1980, I had a Praktica MTL3 with a 50mm f/2.8 Tessar lens, which, if I looked through the viewfinder with one eye, and at the scene in front of me with the other eye, both views seemed to coincide for size.

    That would seem to indicate that 50mm is correct. However, I suppose it does depend on the magnification ratio of the viewfinder, which I do not know.

    I always thought that the 58mm lens supplied with the Zenits was too long.

    Using my Nikon D3100 with 18-55mm lens, the lens has to be set on 55mm to get coinciding views.

    Comments, anyone?
  7. thornrider

    thornrider In the Stop Bath

    I know we are supposed to vote for the 50mm. But it was always too boring in film days - and since I bought a new 50 f1.4 I have only used it on a APS-C camera because it becomes a 75mm. Never used it on the full frame D700 nor on my F100 film camera.

    I voted 35mm - which I do use - it's almost as close to 43mm - but puts things into context in the same way as our eyes dart around a scene rather than staying riveted to one spot.
  8. Benchista

    Benchista Which Tyler

    That's just a matter of effective viewfinder magnification - it's got absolutely nothing whatsoever to do with the image.
  9. Benchista

    Benchista Which Tyler

    I wouldn't, generally. I don't believe photography creates a sense of reality - or if it does, it's a very misleading one, and I prefer to show my viewpoint (in more ways than one) than any definition of reality. As you say, it is (in every sense) a matter of managing perspective. For the most part, that 21mm is closer than most other options for me.
  10. Learning

    Learning Ethelred the Ill-Named

    35mm but then crop from 3:2 to 4:3.
    Often I don't want to create a sense of reality. A longer focal length adds impact.
    Last edited: Mar 12, 2013
  11. Roy5051

    Roy5051 Well-Known Member

    Sorry, I don't see your point. The image consists of what I see through the viewfinder, give or take 5%. If what I see with the naked eye and what I see through the viewfinder corresponds, that is the image.
  12. RogerMac

    RogerMac Well-Known Member

    I voted 50mm as I thought it best answered the question about reality, however I have just done a quick check on a series of images I took on a recent historical walk and by far the most common focal length that I used was 24mm. So if the question had been "If you were restricted to one focal length......" the answer would have to be 24mm

  13. nspur

    nspur Well-Known Member

    I reckon that it should be 55mm for magnification but 35mm for field of view. Given that you can't easily do this in camera I'll go for 42mm.
  14. Learning

    Learning Ethelred the Ill-Named

    Roger that was not the question.
    Before some challenges my own answer let me say that I admit that I also qualified my own answer to answer another question..
  15. Benchista

    Benchista Which Tyler

    Because that's simply not true - you're confusing the viewfinder magnification with what's in your image. You've actually made the point yourself without knowing it - there's a massive difference in angle of view between your old Praktica and 50mm lens and your APS-C with 55mm lens - you're getting similar magnification of the subject in the viewfinder, but you would have a very different result in same-sized prints.
  16. 0lybacker

    0lybacker In the Stop Bath

    It would depend on what I would be photographing.

    If I was making a tight head (or possibly head & shoulders) portrait, 28mm would be more 'unreal' while 75mm or 100mm would be most 'real', depending on aperture used. A half length portrait may well convey 'reality' best by being done on a 50mm lens, especially when at mid-height to the subject.

    In a landscape, both 28mm and 75mm lenses could convey 'reality'. A lot would depend on viewpoint and the specific subject matter.

    In the same way, how we are used to seeing things influences the 'reality' conveyed by a lens.

    Take cricket, as an example. A test match photographed from grass level with a long tele. Batsman edges a ball from a fast bowler to the slip cordon. Patrick Eager, behind an 800mm lens trips the shutter at exactly the right moment with the ball a third of a metre from the hands of second slip. 'Reality' for the newspaper reader the next day? Absolutely. Reality for the paying spectator two or three rows back from the photographer? Absolutely again. 'Reality' for mid-off? Yes, pretty much. 'Reality' for the bowler, by now a third of the way down the wicket ... much less so.

    Make it a local club match and the 'reality' weakens a little. Why? Because we are used to this being more intimate, a smaller ground, closer to the action.

    Change the Test situation from quick to slow bowler, with a lot more fielders circled around the bat and the 'reality' situation changes again, this time also depending on depth of field, the f stop used. Same thing in the club setting - 'reality' becomes different.

    Damien, this has got to be a great candidate for your worst titled, badly written, Poll ever!*

    If I can make time I will try and re-write it for you, but I now need a very strong coffee and TWO chocolate biscuits to recover!

    Aaaauggghhh! :mad::eek:

    * You do make up for it in your explanation, somewhat, so I will let you off lightly. I sentence you to reading every word in every issue of SLR Camera magazine from 1970 to 1979 as punishment! :D Hopefully, you have these in AP's library.
    Last edited: Mar 13, 2013
  17. 0lybacker

    0lybacker In the Stop Bath

    You are wrong and Roy is right.

    Assuming, that is, that in your post you meant to include 'equivalent' but forgot it.

    Welcome back, btw, from your hols(?); I have some more info on the LCE saga for you and will try & post it in the appropriate Thread.
  18. Benchista

    Benchista Which Tyler

    Absolute and utter balderdash. Re-read what he said and what I said - it's precisely because the word "equivalent" ISN'T there that I'm right - had it been, Roy would've been correct. An actual 55mm lens on APS-C clearly doesn't produce the same field of view as a 50mm lens on 35mm/full frame (whereas an equivalent one pretty much would), but can produce the same effective viewfinder magnification if the intrinsic viewfinder magnification of the digital camera is less. So what Roy sees through left and right eyes is all pretty much life-size, but the field of view is radically different both between eye and viewfinder, and in the images taken in each case. It's really not that difficult a concept.
  19. 0lybacker

    0lybacker In the Stop Bath

    1. The Press Release or statements at the time of launch - I seem to remember that. Having said that, it was 'talked up' by our photo press, perhaps due to the influence of ...
    2. Various debates in the photo press over the years. SLR Camera is the one I read, re-read & dimly remember, and still have buried deep in my 'filing system' thanks to acquiring a run of the mag from issue 1! This debate tended to rage in the late '60's and 1970's due to the marketplace switch to SLR cameras which although being sold as 'interchangeable lens' cameras were nearly always 'bundled' by dealers with a 50mm 'standard' lens.

    In one of the periodical debates in SLR Camera (I think in 1972, 1973 or 1974) some opticians, opthalmologists and, possibly even opthalmic surgeons joined in with all sorts of interesting insights into human vision and 'eyesight'.

    I can only dimly remember it but obviously we have the measure 20/20 (or lesser variants thereof) for vision that an optician can provide for each of us but there are other things that are something like:
    conscious directed vision (human eye zooming),
    conscious normal
    conscious but peripheral,
    wide peripheral vision,
    experiential vision or conditioned vision (ref my 'cricket post' re 'reality') and which really corresponds to the thing that happens to a photographer.

    This occurs when a photographer (or a viewer of visual images) that has 'grown up' on fixed focal length lenses, has gained experience of certain angles of view and starts to do what Ansel Adams (& I believe Steiglitz and others before Adams) refered to as 'previsualisation' - although that also refered to not just the optical capture of the 3-D image but the expressive print in 2-D form.

    I have been struggling to remember whether Adams did any research into vision in this specific area. I know he was knowledgeable about colour vision.

    It is potentially fascinating stuff in that there has been a photographic culture change occurring about twenty to twenty-five years ago with some photographers developing all their experience using only zoom lenses.

    It can also be quite important in some other areas of life, like road safety, for example, and with reference to sport might vary according to sport, may even dictate which sports we are good or hopeless at, enjoy or not.

    Hopefully, we may have an optician or two as Forum members and they can put me right on the above or list it with the correct technical terms and in some good order!;):)
  20. Zou

    Zou Well-Known Member


    The reason I ask is that I have never met anyone with such a narrow field of vision. I have never heard any real evidence that a format's 'normal' lens represents the field of view of the human eye; rather a 'normal' lens represents perspective close to normal vision. Quite a difference between those two ideas.
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