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January 11th, 2007, 07:26 AM | #31 |
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A little bit off-topic, the motion film image aesthetic we have become accustomed to is not so much related to the frame rate of 24FPS so much as the shutter speed which became associated with it, 1/50th sec or thereabouts.
This creates the motion blur which most nearly approximates the human persistence of vision. 24 frames per second can be counted by humans. It is easy. Any half good musician can do it. Some, probably many musicians can tell you when a piece of music has been played against a click track. A soldier can learn to count bullets fired out of an automatic weapon. When I was a kid, we used to cheat the payphones by tapping out numbers on the buttons inside the hang-up hook. You learned to do it by counting groups. Threes are easy. Phone 0 = 3 x 3s + 1 etc.. ( _--,_--,_--,_ ) This is where my off-topic comes in. My own half-baked theory on why 24P or 25P has come to be preferred along with it having been there from way back is that the detectable frame rate establishes a timing or pace we can subconsciously relate to. When there is a story jump or a flashback, we can acclimatise to the new environment because that 24P is chattering away at our subconciousness. Back to bokeh. If there are no very overexposed pinpoint highlights in an out-of-focus background, there is less apparent difference between the film image and the groundglass relay to video image. The selection of a lens to soften background is as much about the director or DP seeking to draw our concentration upon a person or object, to manipulate our perception, sometimes to hide apparence of something in the frame from our immediate view. Sometimes it is to set off a threat/apprehension reflex by having something out of focus move subtly in the peripheral vision area even in otherwise good lighting. That is where you have a problem with the depth of field of small format video. Such a contrivance is not quite as easy to achieve but one way it can be done is by burying much of the scene in darkness, to cheat out the obvious perspective inconsistencies caused by sitting off your subject with a long lens. Just a few red herrings from a non-expert into the mix to carry you away. |
January 11th, 2007, 12:44 PM | #32 |
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James,
I disagree with idea that we should be trying to emulate what our eyes see. If this were true, DP's would always use normal lenses and never switch to wide angle or telephoto, because our eyes dont "see" that way. I read a book about James Wong Howe, and in it there is a section on Realism. It says that art of motion picture is to show an enhanced reality, because reality alone (or a perfect duplication of the real world) would not engage the audience. So if Realism, and not reality, is the goal of a photographer, it seems that to tell others on this forum to shoot so it looks real, like our eye's see, may be poor advise. The bottom line for me is that 35mm adapters help small format video look more like 35mm film. This forum exists because the devices can improve visual storytelling, the footage looks more pleasing (to most I guess?) |
January 11th, 2007, 01:18 PM | #33 |
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I'm mainly just talking about about the feel of the motion and blur. Of course we like to see life in different perspectives, but we want it to look sureal not fake. As Bob said 1/50th sec shutter speeds are closest to the human eye, which is why we use it. I may be wrong, but isn't that why we shoot at 24fps or 25fps because if we shot at 50fps with 360 degree shutter it would look wrong. Ive always been taught to usaully shoot at about twice that of your your framerate in most situations.
Like I said before the adapters are nice and all, but they do look fake and are a bit of a distraction. It does look a hell of a lot better than having an infinite DOF, but I would say most can agree that in this case we are trying to emulate the human eye and the 35mm apatpers are way off. |
January 11th, 2007, 01:34 PM | #34 |
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I do not agree that the shutter speed is more of what creates the film look (or similarity to our vision, etc) than the frame rate. 24p toggled between a 1/50th shutter and a 360 degree shutter (i.e. none) looks only subtly different--there is certainly more blur as expected but it still retains a filmic look.
However the visual difference between 24 and 60 fps is extremely noticeable, even by a "civilian". On most of the high end HD jobs I've done the shutter is occasionally switched off to gain the extra stop, with the reasoning that it is a worthwhile gain against the slight difference in look. However switching the frame rate is something that would jump right off the screen and cue the audience that something is up. It's typically used for the effect of cutting to a TV broadcast or view through a video camera--the difference in look is meant to be jarring.
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January 23rd, 2007, 03:17 PM | #35 | |
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Doubtless there are some people who can't bring themselves to admire the look of the various 35mm adapters, & perhaps it is also true that more than a very small fraction of viewers will notice a difference between adapter & film bokeh in the context of a put-together cinematic work. But it is equally true that the adapter bokeh pleases a great many people in its own right, & then again, it is implausible to me that the majority of viewers are so discriminating in this respect as you suppose. The last said is, of course, an empirical question, not something that can be known by any quantity of hearsay & anecdote. For every person of your acquaintance who rejects adapter footage because of its bokeh, I or others could produce a counterpart who has no such qualms, often in the form of working professionals who use adapters on the job. Who buys & rents all those Mini35s? The upshot is that your calling the look of these adapters 'amateur'--aside from being by definition nothing of the sort in light of their professional use--is a subjective, & rather dogmatic, aesthetic judgement on your part for which you give no real aesthetic arguments. I don't condemn your opinion, but I think you're coming at it rather confusedly & on shaky argumentative grounds. Returning, for instance, to your assertion that the whole endeavor of filmmaking has been concerned since its inception strictly with attempting to ape human perception. That is plainly insupportable. Avant garde cinema has never been so shackled, people who continue to shoot black & white aren't merely pandering to an audience of the colorblind: what were film noir or German Expressionism all about? Obeisance to the human eye, & a misconstrued model of the eye at that, shouldn't be the limit of cinematic possibility, any more than it ought to be for painting. Leaving to one side, of course, the dubious proposition that 24fps/35mm bokeh is the utmost in verisimilitude. The 35mm DoF adapter is a tool I'd rather not discard owing to its aesthetic difference from the older technology. It does a lot more than throw a little blur about the screen of this or that nature. It handily solves, for one thing, the problems of composition thrown up by the endless depth of field of small-chip video. R. Mutt |
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January 23rd, 2007, 04:10 PM | #36 |
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The human eye makes poor bokeh. Just stare at a streetlight at night... more of a pointy-edged blurry glob than a clean, graduated disc. Maybe I can upgrade my retinas to film.
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January 23rd, 2007, 04:27 PM | #37 | |
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24 fps as a standard is an accident of history, not the end product of a concerted effort to reproduce human visual perception to a nicety, if such a thing were even possible. It came about for the most part as a compromise between the competing interests of overcoming strobing (at which 24fps is only partially sucessful, as we know) & economizing on film stock. But beyond this, & more fundamentally, you appear not to understand much about the human perceptual faculties upon which you are grounding your opinions. Perhaps it's down to the fact that film theorists amateur & professional tend to exist in their own realm removed from the wider field of scientific understanding. Ever since the seminal Gestalt experiments of the early part of the 20th century, it's been known that the human perception of continuous motion built up of a series of sensations of discontinuous images has nothing to do with the theory of persistance of vision. See, for instance, http://www.uca.edu/org/ccsmi/ccsmi/c...0Revisited.htm . Persistance of vision is a myth. Most film theoriests, however, are content to bandy about the terminology of outmoded 19th -century science. In a nutshell, the eye is not a camera, & the camera cannot aspire to be an eye. Human perception has as much to do with what goes on behind the retina as in front of it, to paraphrase Max Wertheimer. Sensations received at the retina are filtered through a complex system of mental processes, influenced by beliefs, ideas, moods, & even more elusive subjective states, to issue in a perception. There is no monolithic human visual (or any other) perception, & unless you can build a camera that functions just as our visual perceptual apparatus does (not to exclude the brain), it's nonsense to talk of a direct correspondence between the optical characteristics of a camera device & what people see. As for your belief that the current practices of film production ought to exist in the way they do because of some relationship to the nature of the world, any introductory philosophy course would serve to show you that you can't get an ought from an is. If you don't like adapter bokeh & want to clothe your taste in persuasive argument, you would do better to look elsewhere than perceptual psychology for your premisses. H. |
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January 23rd, 2007, 04:56 PM | #38 |
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I had always been under the impression that 24fps was a cost-cutting measure anyways. It was to extract the least amount of film for the buck and 24 was the most they could cut without the consumer noticing - at least that is what I had heard.
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January 23rd, 2007, 10:11 PM | #39 |
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24 fps
True and true. Historical accident and cost-cutting measure. In early cinema approximately 50 fps was judged as generally acceptable for creating the illusion of persistence of vision, though in fact the human eye is cabable of percieving frames even faster than 1/250th of a second. But 50ish was judged "good enough."
50 or 48 fps is still not very economical, however. So, cost-cutting industrialists that early filmmakers were, they discovered that they could flash each frame twice on the screen, and viewers wouldn't really notice. So they could cut the exposed frames in half (and also double the exposure time--a key point). That's why to this day, in a professional projector, each frame is "flashed" twice, producing 48 frames per second. That's how you can shoot at 24 and still have motion seem more-or-less seamless. As to why 24fps transferred (or interpolated) to 29.97 looks better than straight 29.97, that's a whole different question, related to a convention of rythmical cadence and motion blurring. But it has nothing to do with how the human eye "naturally" perceives the world. If that were the case, we'd always prefer images shot with a squishy lens whose very shallow focal point flits around the frame sporadically, even spasmically (in x, y,and z-planes to boot), to create a whole image: very "naturalistic" (that's how the human eye "really" sees), but IMO impossible, even painful to watch on a screen. Henry, correct me where I'm wrong here. Last edited by Jack Davidson; January 24th, 2007 at 08:15 AM. |
January 23rd, 2007, 11:01 PM | #40 |
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Back on subject for a bit... I have been pretty unhappy with the low-end 35mm adapters for this reason. The LetusXL works pretty good as it attaches to the camera direct, not in front of a lens. It has a 2X crop factor though. I personally never liked the M2, too hard to set up and only looks good in optimal light conditions. Most of these adapters end up looking like bootlegs of 35mm shots. I recently tested out a Brevis on the HVX200 and it looks better than anything I have tried and is EASY to set up. The options for multiple diffusers really sells the deal, I just ordered a big kit from them.
On a slightly unrelated note but concerning bokeh, I have a Canon 20D and a CHEAP EOS to FD adapter so I can use old FD lenses. The cheap adapter creates some GREAT bokeh, great in that, it looks mesmerizingly fake in certain conditions. Really unique effect, I will try to post a pic. ash =o) |
January 24th, 2007, 12:59 AM | #41 |
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I seem to recall reading somewhere that the 24FPS, was a rate in an acceptable ballpark but may have been determined by conveniently available mass-produced reduction gear sets suited to single phase AC 60Hz induction electric motor speeds.
This was apparently also the case when the 78rpm record standard was created. I could be wrong. |
January 24th, 2007, 08:31 AM | #42 | ||
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January 24th, 2007, 08:39 AM | #43 | |
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I recalled the 24fps thing being related to sound.... after a quick interwebs search:
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January 24th, 2007, 06:16 PM | #44 |
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16 & 18 fps
It's true. 16 and 18 fps were very common in the pre-sound days. And 24 fps mag (or optical) did offer better sound quality. But even though 24 fps would (and did) offer better sound fidelity, 24 was still, after all, a(n) historically agreed upon convention. For what it's worth, 60 fps (in either mag or optical) has tremendously more fidelity than 24. So if that's the argument, why not 60?
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January 24th, 2007, 07:04 PM | #45 |
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35mm adapters are fake ;)
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