Perspective (was Re: Has ultrawide angle become an overused cliche?)
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From: Neil Harrington on 9 Aug 2010 14:42 "David J Taylor" <david-taylor(a)blueyonder.co.uk.invalid> wrote in message news:i3peu3$19m$1(a)news.eternal-september.org... > "Savageduck" <savageduck1@{REMOVESPAM}me.com> wrote in message > news:2010080909524211272-savageduck1(a)REMOVESPAMmecom... > [] >> What you are calling a "wide angle perspective" is actually a "wide angle >> view". If you had obtained the same change of "view" with a 50mm prime, >> by moving the camera away from the subject, there should have been a >> change in perspective along with the change in view. >> >> -- >> Regards, >> >> Savageduck > > That's an excellent term, thank you. The problem with "wide angle view" is that it doesn't really convey the same information at all. Consider some shot of a distant horizon. If there's nothing else in the picture to serve as a clue, it's likely to be impossible to tell whether it was taken with a wide lens or a long one. So it may be a wide angle view, or it may not, and one might look at the picture for years and never be able to tell. Such a picture has for all practical purposes *no* perspective. With the short-lens shot of Duck's car, though, one instantly sees that it's taken with a very wide-angle lens, and what announces this is the unusual perspective.
From: Truman on 9 Aug 2010 15:18 On Mon, 9 Aug 2010 12:06:07 -0400, "Neil Harrington" <nobody(a)homehere.net> wrote: > >"Bruce" <docnews2011(a)gmail.com> wrote in message >news:klfu561gfbchtjar4d7l6pehdq8dcv0kll(a)4ax.com... >> On Sun, 8 Aug 2010 16:43:55 -0400, "Neil Harrington" >> <nobody(a)homehere.net> wrote: >>>"Bruce" <docnews2011(a)gmail.com> wrote in message >>>news:ugar46dfhpou4nimibd86jm53iqo459f99(a)4ax.com... >>>> On Mon, 26 Jul 2010 09:54:10 -0400, Shiva Das <shiv(a)nataraja.invalid> >>>> wrote: >>>>>In article <5k2r46pe2t2t7tsjn802pa3o5v7lla946f(a)4ax.com>, >>>>> Bruce <docnews2011(a)gmail.com> wrote: >>>>>> It also doesn't help when people associate perspective with the lens's >>>>>> focal length. Perspective is purely a function of viewpoint and its >>>>>> relationship with the subject. The focal length of the lens is >>>>>> irrelevant. >>>>> >>>>>In "Photographic Lenses: Photographer's Guide to Characteristics, >>>>>Quality, Use and Design" Ernst Wildi has two sets of photographs using >>>>>progressively longer lenses from 38mm to 500mm Hasselblad lenses (20mm >>>>>to 255mm equivalentin 35mm film format). >>>>> >>>>>The first sequence, one shot per lens, is taken standing in the same >>>>>spot looking at the same scene. The second sequence is of a lovely lady >>>>>on the beach and he moved the camera to keep her the same size in each >>>>>image. >>>>> >>>>>It does a great job of showing how focal length and distance affect >>>>>perspective. >>>> >>>> >>>> Yes, that is the classic method of demonstrating that perspective is >>>> independent of focal length. >>>> >>>> It is to be found in many books on photography, yet people still keep >>>> making the same mistake over and over again, thinking that perspective >>>> is dependent on focal length. >>> >>>But perspective *is* largely dependent on focal length. >>> >>>The the other poster mentioned ". . . how focal length and distance affect >>>perspective." >>> >>>Focal length is not "irrelevant." Both are important: focal length *and* >>>camera position. A shot taken with a wide-angle lens has wide-angle >>>perspective, which (assuming there are enough objects arranged in the >>>scene >>>to establish perspective at all) is easily recognized by anyone looking at >>>the resulting photo. To say that focal length is irrelevant is to deny >>>what >>>anyone can see with his own eyes. >>> >>>(Sorry for being more than a week late in replying to this, but I only saw >>>the thread just now. The misunderstanding is important enough to correct. >>>The "many books" that support the idea are mistaken, as are the several >>>people who have repeated it over the years.) >> >> >> The "misunderstanding" is entirely yours, Neil. It is a very common >> misunderstanding. However, it doesn't matter how many people repeat >> it, nor how many times, it is still wrong. There is no such thing as >> "wide angle perspective". > >Are you really telling me that you can look at a photo of, say, an interior, >taken with a 20mm (equiv.) lens, and NOT be able to tell BY THE PERSPECTIVE >that it was taken with a wide angle lens? > >Again, to deny this is simply to deny the evidence of your own eyes. > >> >> Perspective is purely a function of viewpoint and its relationship >> with the subject. The focal length of the lens is irrelevant. > >Simply not true. Yes, I have seen all the alleged "proofs" of this fallacy >and it remains a fallacy. > I hate to break it to all of you (no I don't), but all of you are right, and all of you are wrong. perspective noun [MF, prob. modif. of OIt prospettiva, fr. prospetto view, prospect, fr. L prospectus � more at prospect] (1563) 1 a : the technique or process of representing on a plane or curved surface the spatial relation of objects as they might appear to the eye; specif : representation in a drawing or painting of parallel lines as converging in order to give the illusion of depth and distance b : a picture in perspective 2 a : the interrelation in which a subject or its parts are mentally viewed <places the issues in proper perspective>; also : point of view b : the capacity to view things in their true relations or relative importance <urge you to maintain your perspective and to view your own task in a larger framework � W. J. Cohen> 3 a : a visible scene; esp : one giving a distinctive impression of distance : vista b : a mental view or prospect <to gain a broader perspective on the international scene � Current Biog.> 4 : the appearance to the eye of objects in respect to their relative distance and positions per�spec�tiv�al \per-"spek-ti-vel, 'per-(')spek-"ti-vel\ adjective (C)1996 Zane Publishing, Inc. and Merriam-Webster, Incorporated. All rights reserved. Just think, how many photo opportunities you've all missed while arguing about it. More than you've missed by changing lenses.
From: Neil Harrington on 9 Aug 2010 15:41 "Savageduck" <savageduck1@{REMOVESPAM}me.com> wrote in message news:2010080910544650878-savageduck1(a)REMOVESPAMmecom... > On 2010-08-09 10:04:14 -0700, "Neil Harrington" <nobody(a)homehere.net> > said: > >> >> "Savageduck" <savageduck1@{REMOVESPAM}me.com> wrote in message >> news:2010080908280775249-savageduck1(a)REMOVESPAMmecom... >>> On 2010-08-09 06:22:13 -0700, bugbear >>> <bugbear(a)trim_papermule.co.uk_trim> >>> said: >>> >>>> Savageduck wrote: >>>>>> >>>>>> I just performed a simple resize of the second image and laid it on >>>>>> top of the first: >>>>>> >>>>>> http://www.mike-warren.net/play/savageduck.jpg >>>>>> >>>>>> Perspective is unchanged. >>>>> >>>>> Damn! I should have thought of doing that. >>>>> >>>>> So it seems the eye is easily fooled by focal length changes. Thanks >>>>> for >>>>> the proof you provided, It kind of takes the wind out of my sails, but >>>>> there it is. >>>> >>>> Here's all of the above, all mixed up >>>> >>>> http://en.wikipedia.org/wiki/Dolly_zoom >>>> >>>> BugBear >>> >>> >>> That really does mess with perspective due to the changing >>> camera/subject >>> distance. >>> Now that would really have been a problem for me since my idea was to >>> keep >>> the camera/subject distance constant to see if there is a perspective >>> change due to focal length change. >> >> And there was. >> >>> ...and my own shots have proved to me that there is no perspective >>> change >>> due to focal length change. >> >> No, what was proved to you was "that there is no perspective change" OF >> THAT >> SMALL PART OF THE PICTURE. How could there be? >> >> Look at it this way: Suppose you just used one zoom lens and changed from >> its shortest focal length to its longest, changing nothing else. At the >> shortest f.l. (assuming a wide-to-tele zoom) the picture would have the >> familiar wide-angle perspective. As you zoomed in, you would just be >> progressively magnifying the central part of the picture -- so the >> perspective OF THAT PART could not possibly change. >> >> That is essentially the same thing Mike's resizing part of your second >> photo >> has done. >> >> Again: perspective is something that involves the entire picture. That is >> why the various "proofs" that perspective depends solely on camera >> position >> are fallacious -- all such "proofs" that I have seen involve using >> smaller >> parts of the picture which have their own, different perspective. > > I think the problem is we each have our own interpretation, or > misinterpretation of "perspective" and/or view. > I have always thought of change of perspective to be relative to position > of view point or camera. It is. But my point is that isn't the *only* thing that bears on perspective. > For example using the classic vanishing point lines of convergence an > artist might use, the perspective remains constant at all points between > those converging lines. That is effectively what happens with a zoom lens > changing FL. Move the camera, or view point laterally and there is a > change in perspective. Taking shot down a set of parallel railroad tracks > will show a converging vanishing point. Change the FL of that shot, and > the vanishing point remains the same, but the view has changed. Now move > the camera laterally and the perspective can be changed until all that is > seen is the side of a single rail. Yes. But the perspective can be changed even without moving the camera. Suppose for one example a similar situation, a shot down a long straight hallway with a flat wall at the end, and a sign painted on the wall (which is of course perpendicular to the lens axis). With no other features in the scene but the straight parallel lines between floor, walls and ceiling, zooming down the hallway indeed would not change the perspective in any visible way. This is assuming there are absolutely NO other features in the hallway. The only elements that can provide perspective are those four parallel lines all converging on a vanishing point. But if zoomed in to the point that only the flat wall and sign were visible, all perspective would disappear, since a flat perpendicular surface can provide no perspective. Now suppose the same situation but with pictures painted on the walls all the way down. In this case the perspective *would* change as the lens was zoomed in. At the short f.l. end, the pictures on the walls would show more foreshortening with distance, i.e. the same wide-angle "distortion" that makes people's heads egg-shaped at the edges of the picture would be apparent, and this would be eliminated as f.l. was lengthened. And that sort of wide-lens foreshortening could *not* be duplicated with a long lens from the same viewpoint. If you take a very wide-angle shot of almost anything, it is only the *central* portion of the picture that keeps the same perspective as you go to a longer f.l., because you're just magnifying that same part. (In one way or another this is the "proof" always given by the viewpoint-alone-determines-perspective believers.) But with that longer f.l. you could never get the same perspective that you did at the *corners* of the w.a. shot. Even though shooting from the same viewpoint, you'd have to redirect the camera which would change the perspective, and in most cases the change would be very apparent. An example of this effect is here: http://www.kenrockwell.com/tech/digital-wide-zooms/comparison-sharpness-12.htm Look at the corners pix. Even though Rockwell didn't use long lenses for comparison, his enlargements of the wide angle photos' corners make the point. Long lenses obviously would not have produced the perspective shown in these w.a. corners. > > All very interesting, and thought provoking. Like you, I also find it > difficult to deny the thought that a change of FL such as the one I made > does not result in a change in perspective. Indeed.
From: Bruce on 9 Aug 2010 16:13 On Mon, 9 Aug 2010 12:23:08 -0400, "David Ruether" <d_ruether(a)thotmail.com> wrote: > >Ah, the above reminds me of my teaching days.......! ;-) I found it >easy using a blackboard and chalk, drawing a "lens", a "stick figure", >and a "film plane" to show the effects of keeping FL constant, changing >FL, keeping the film plane constant in size relative to the FL or changing >that, and the effect of changing the lens opening size on an out of focus >image on the film plane using drawn sections of "cones" of light... >Fun! It is fun, especially if you have a receptive audience. But it takes only one Neil Harrington to spoil the party. ;-) >(But the most fun was getting people to "see" that they don't see >straight lines off the center of their vision that are strait in the subjects >they look at - in other words, we don't see in rectangular perspective...;-) It's fascinating how the eye and brain work together. The eye "sees" like a fisheye lens, but the brain corrects it to rectilinear. It is rather like the Nikon 10.5mm fisheye, with software "correcting" the results to rectilinear ... ;-)
From: Neil Harrington on 9 Aug 2010 16:37
"Bruce" <docnews2011(a)gmail.com> wrote in message news:74o06692o0kh4bf29glsnj8lvno7guev9l(a)4ax.com... > On Mon, 9 Aug 2010 12:23:08 -0400, "David Ruether" > <d_ruether(a)thotmail.com> wrote: >> >>Ah, the above reminds me of my teaching days.......! ;-) I found it >>easy using a blackboard and chalk, drawing a "lens", a "stick figure", >>and a "film plane" to show the effects of keeping FL constant, changing >>FL, keeping the film plane constant in size relative to the FL or changing >>that, and the effect of changing the lens opening size on an out of focus >>image on the film plane using drawn sections of "cones" of light... >>Fun! > > > It is fun, especially if you have a receptive audience. But it takes > only one Neil Harrington to spoil the party. ;-) Sorry if my correcting your error "spoils the party," but -- c'est la vie, as they say in Uzbekistan. :-) |