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

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

  1. RogerMac

    RogerMac Well-Known Member

    Nice camera BTW. I still have mine and used it in the relic challenge, I has one great virtue - a DOF scale - and I just set it to f8 and everything from about infinity to 7 ft was in focus, very relaxing

    Roger
     
  2. Terrywoodenpic

    Terrywoodenpic Well-Known Member

    I have been very happy with a number of focal lengths

    The 50mm on my Agfa Sollinette 2 seemed just right.
    As did the 40mm on my Olympus trip.
    Or the 35mm on my OM1m

    Perhaps the best of all was the 75mm on my first Rolleiflex.

    In most situations any of these are just fine, It is just a question of moving your legs a little. The resulting viewpoint from any of them is very acceptable as "Normal".
     
  3. Benchista

    Benchista Which Tyler

    Absolutely - it's precisely that.
     
  4. P_Stoddart

    P_Stoddart Well-Known Member

    I have had alook at the Olybacker replies I cannot see anything offensive myself. :confused: :)

    I believe viewfinders don't always show the true image from the lens on the camera.

    I remember using my MTL3/5 and finding something at the edge of the image that was not there when I composed the shot.

    You do see in specs it being pointed out that said viewfinder is 100% so WYSWIG in term of shooting for composition. Mainly top end models I believe.

    Best way surely is to try and compare final image from camera to that scene. I think something like that has been done using a print overlayed at the shooting site.
     
  5. thornrider

    thornrider In the Stop Bath

    Replies to Olybacker.

    And to you in the last month or so ?
     
  6. P_Stoddart

    P_Stoddart Well-Known Member

    Yeah, I meant Nick's replies to Olybacker.

    Olybacker asked for a apology, Nick refused. :)
     
  7. Atavar

    Atavar Well-Known Member

    Please correct me if I'm wrong (Please do as I'd like to know why viewfinder magnification matters), but isn't the point of an SLR to get a sensor/films eye view of the image in the viewfinder?

    If that is indeed the case, does the magnification factor of the viewfinder actually mean anything? If the viewfinder gives a good impression of the final image (give or take up to 5% of the edges in some models), and if keeping one eye open to get the perspective comparable to reality, what is the magnification factor of the viewfinder actually for? If a magnified viewfinder composed image is made to resemble a life-perspective, and the sensor captures something within 5% of the viewfinder depending on model, would this not indeed produce an image in comparison to what the open eye was seeing? Is this magnification to counter for design difference? Maybe a smaller mirror box or viewpath in slightly the wrong place or something? It's shirley not to make the viewfinder bigger, as they rarely are... Or are they? And if that were the case, I point to my original point - the viewfinder displays pretty much the intended final image...

    Magnification in a viewfinder just sounds like marketing jargon to me - it, in my ideal little world, displays what the sensor is seeing, otherwise what would've the point of it all?

    So, depending on the focal length you set it to provides a life-perspective reproduction, magnification in the viewfinder should have minimal effect on the actual end image composed for a life-perspective image.

    If that made sense: am I wrong?
     
  8. daft_biker

    daft_biker Action Man!

    Think of it like TV size......you could buy a really big TV and sit really close to simulate a viewfinder with an uncomfortably high magnification. Or sit really far away from a small TV for the opposite effect.

    From what I've seen there's a trade off between what can be viewed comfortably and, for example, how easily and precisely you can place the focus. Too big and you have to strain you eye to see the edges of the frame, too small and it's difficult to focus manually.
     
  9. Atavar

    Atavar Well-Known Member

    Ah, Cheers for this, that makes sense user-friendliness speaking :)

    As far as the focal-length to reflect reality goes, having searched, I found an article on Luminous Landscapes which states:

    "1X is the size that things appear to be when you look at them with your eye (a.k.a. "the naked eye"). Now, obviously, magnification also changes when you use different lens focal lengths — telephotos make things look bigger, wide-angles make things look smaller. So camera magnification is specified with a 50mm lens." http://www.luminous-landscape.com/tutorials/understanding-series/viewfinders.shtml

    So, if I'm getting this right, let's say a view finder is 1x - 50mm would be 'life sized' as far as we are talking about with getting an image to match what a naked eye is seeing.

    So a 0.75x magnification many pro cameras are close to having (Please read the article at the end of that Web-link to find out why, the section under the title 'Life is a Cabaret, Old Chum') would mean a focal length of about... I'm dire at maths, so let's say 62.5mm for a comparable 'life size' image, bearing in mind that a 100% viewfinder does display the full final image that is captured, the size of objects in the final image would match that of a naked eye, but bearing in mind the focal length perhaps not the perspective...

    So if I'm getting the swing of the actual argument here, it's not nessicerrily that the image is not the same size as compaired to the naked eye - it's that the actual perspective of the required focal length to match the viewfinder magnification, may not be correct to match the naked eyes perspective of the world? We can get it the same size but not always the same angle?

    Would I right in saying that? And if so, thank goodness my VF is 0.94! :)
     
    Last edited: Mar 18, 2013
  10. Atavar

    Atavar Well-Known Member

    *note* in my above post, when I say 'angle', I don't mean angle of view, you'd need a 10mm fisheye to get the angle the eye catches, I mean the perspective, the distance and angle of objects in the frame in relation to each other.
     
  11. 0lybacker

    0lybacker In the Stop Bath

    The key (not necessarily the cause) to Benchista's, Nick's, problem is that he is telling Roy that what Roy is seeing through Roy's eyes cannot be, is wrong. That, I have suggested, is wrong. For obvious reasons. :rolleyes:

    I'm not actually too bothered about an apology, more by the overbearing and rather poor behaviour of a Moderator! On which he has form! :eek: Someone posted the other day, on an old/resurrected Thread, how many members are no longer here or, at least, active. My feeling, when battered is 'Why do I bother with this?' followed by, 'This is a great excuse to give up'.

    The chance to escape 'Hotel California'? Become a blast from the past, merely pushing tumbleweed. :confused:

    Aah, now there's a thing! :D
     
  12. 0lybacker

    0lybacker In the Stop Bath

    Agreed. Still use mine from time to time. Have a roll of Pan F in there at the moment. Last roll was XP2 where, strangely, the frames where I used a yellow filter are actually tinted yellow on the developed film. :confused: Film, via dev, has obviously retained some 'colour' properties.

    Wanted, had planned to join in TRC - is there still time? - but just as I got all enthusiastic, pressure of work, other activities plus two exhibition opportunities, one at short notice, left me with a roll of 120 in my late mother's 1938 Voigtlander Bessa part-exposed.

    The Everest of four more frames has yet to be climbed! Despite the snow. If someone could push the latest lot further south, that might be the trigger to get me out into the countryside. ;):D
     
  13. daft_biker

    daft_biker Action Man!

    I have no use for the maths I'm afraid....my viewfinder is 1x and 100% and it works for me :) I think you've got the jist of it though.

    I usually shoot with my left eye shut and right eye to the viewfinder so it doesn't matter to me which focal length on the camera makes things look the same size in both eyes. It's not going to effect my lens choice or what I want out of a shot. What matters to me is how accurately I can frame and focus.
     
  14. RogerMac

    RogerMac Well-Known Member

    TRC seems to have drifted away for its original concept and timeframe and is now a thread where people post images from old cameras and comment on them. As such it is a pleasant place to visit and see some excellent images. Not to mention chatting about old cameras, the only reason I stopped posting was that I ran out of interesting (working) cameras.

    Roger
     
  15. 0lybacker

    0lybacker In the Stop Bath

    We are still missing some input from an expert on human eyesight.

    There must be an opthalmologist or two or an eye surgeon as members of the AP Forum?

    :confused:
     
  16. thornrider

    thornrider In the Stop Bath

    We are still waiting for the expert view.

    But in the meantime there appears to be a difference between perspective and field of view.

    In the case of perspective then this would probably refer to the apparent relative distance between points at different distances in front of you. Thus to be natural in terms of perspective then a lens has to be the same size size as the diagonal of the film you are using (full frame for the digis only). That would be 43mm for 35mm film and 80mm for 2 1/4 square.

    For field of view - which I think some people are confusing - then this could be anything up to 270 degrees because the eyes swivel constantly even when trying desperately to look straight ahead - as was proved to be the case by a team who studied pilots eyes when landing a plane. No lens can match the eyes field of view - unless perhaps for scientific purposes?

    Thus a natural lens can only, in my view, reasonably be related to perspective - and be the nearest commercially available approximation to 43mm for full frame. Since these generally don't exist then the area open to interpretation is whether you prefer as individuals images taken with which lens is a bit more or a bit less than 43mm. This could just as easily be 35mm or 50mm depending on personal preference of the images.
     
  17. beejaybee

    beejaybee Marvin

    Did you ever try to land a plane?

    Controlling direction is only a small part of the issue - you need to judge sideways drift, height and angle of attack simultaneously, as well as watching air speed indicators and maybe other instrumentation. It's not surprising the eyes are all over the place; "trying desperately to look straight ahead" is going to lead to the sort of landing you'll be lucky to walk away from.

    In the era before radar, fighter pilots discovered that they needed an effective full sphere of vision: twisting the neck continuously, rolling and weaving from side to side so as to be able to check the blind spots beneath the wings and behind the tail. For the same reason, it's no coincidence that flying insects and birds tend to have something very close to 360 degree vision; even predators like hawks & owls which have more restricted vision (so as to have better depth perception for striking their target) have an exceptionally large range of neck movement, and use it.
     
  18. thornrider

    thornrider In the Stop Bath


    No - cars and bikes are my limit.


    But after a number of crashes an accident team were concerned that pilots were not looking at the runway - and felt that they should be. Hence the tale.
     
  19. daft_biker

    daft_biker Action Man!

    Surely you only have to shoot from a natural looking place to get natural looking perspective. It's only when you pick a weird viewpoint that that the perspective looks different to what we might expect......or use a fisheye lens.

    The easiest example I can think of is with a moderate wide-angle, lets say 24mm on FF, as it can be used to present a pretty ordinary view of things if you shoot at eye level and a pretty dramatic view of things if you crouch down and jam some foreground up the lens hood.

    Exaggerate perspective = go closer. Compress perspective = go further away. The focal length of the lens just lets us control the field of view.
     
  20. P_Stoddart

    P_Stoddart Well-Known Member

    What about edges though? On a 24mm you are going to get any subject distorted or falling into the frame. That happens less on a longer lens.
     

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