Film-Tech Forum ARCHIVE: Why Doesn't Video Look Like Film????

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Posted by Joe Redifer (Member # 3) on 01-11-2002, 03:32 AM:

There is an interesting thread called "Why does a handy cam not look like film?" going on in a DV forum where people are saying that basically it is just the lighting and whatnot that gives a film its "look". Now maybe I am misunderstanding the original question, I dunno, but now this thread has people arguing that aquisition of the image really isn't all that important, but more so the presentation of the finished product (or something like that). I replied a couple times. I'd like to see more logical arguments for our case, of course!

Check it out:

Click here

Feel free to give me some more firepower or join in. Or maybe let me know that I am wasting my time on that site with my arguments

Posted by Brad Miller (Member # 2) on 01-11-2002, 03:39 AM:

Ahhh, vidiots!

Video doesn't look like film because it ISN'T film and it is very much so inferior to film for all of the reasons you mentioned. No offense to the guys over there, but anyone who thinks video does look like film is obviously an amateur videographer. As time passes and they gain more experience, they will understand the difference.

Perhaps the comparison of Home Improvement (video) vs. Malcolm in the Middle (film) was made, they would get it.

Posted by Thomas Hauerslev (Member # 566) on 01-11-2002, 04:02 AM:

I remember seeing a SHOWSCAN short once, where the look of the film was like looking at video. The image and resolution quality was stunning, but I couldn't help noticing the look of video. Maybe because of the hyper reality SHOWSCAN presents. It's a "cinema look" that was so unreal compared to regular film.

Strange world

------------------
Cheers, Thomas
..in70mm - The 70mm Newsletter

www.in70mm.com www.dp70.com www.70mm.dk www.hauerslev.com http://hjem.get2net.dk/in70mm

Posted by Joe Redifer (Member # 3) on 01-11-2002, 04:53 AM:

I agree 100% with Thomas. I think frame rates are the key. Ever notice how horrible soap operas look? They seem to use the 60 field per second frame rate. It loses that "fantasy" look and instead looks more like the local TV news.

Posted by Dick Vaughan (Member # 540) on 01-11-2002, 05:16 AM:

Thomas / Joe

I saw the Showscan "Tour Of The Universe" at the CN Tower a few years ago and totally agrre. It seemed to haver that edge sharpened feel of video . Although not quite as pronounced I noticed a similar effect when watching the IMAX HD (48fps) film " Momentum" at Canadian Museum of Civilization in '95.

Posted by Scott Norwood (Member # 30) on 01-11-2002, 06:09 AM:

A few quick points:

- film has grain, videotape doesn't
- film has a wider exposure latitude and thus is capable of capturing better shadow and highlight detail
- different film stocks have different looks (e.g. compare Kodachrome with Vision 500T), whereas the CCDs (or tubes) in any given type of video camera all pretty much look alike (though different models also look different)
- if they're talking about film as viewed on video, there's the issue of the transfer process, which allows for many types of image manipulation and color/exposure correction, etc.
- stuff shot on film usually has a higher budget than stuff shot on video, which generally translates into stuff like a better DP, better lighting, better post-production work, etc.

But, yeah, it all comes down to the fact that these are two completely different media. Asking "why doesn't film look like video" is a bit like asking "why don't oil paintings look like photographs."

Posted by Matt Close (Member # 996) on 01-11-2002, 06:47 AM:

Joe,
I believe it is just as your post on the DV site states ... film is 24 frame/s, and NTSC video is 60 fields/s. Video has that 'cheesy' look to it because of 'interlacing'. NTSC video is actually shown at 30 frames/s, but each frame is made up of two 'fields'. If you look at the make up of a tv picture in terms of 'lines', you can refer to them as 'odd' and 'even' lines... or 'odd field' and even 'field'. This was developed originally by some clever cookies to eliminate visible flicker on the screen.... and as a result, motion looks far smoother than film could ever produce. I read a thread on here the other day that queried why when panning accross a cinema screen, things seem to look 'jumpy' and 'hard to follow'. It is because of the frame rate of 24fps. [ At least, I think it is, isn't it?

]Now 30 frames a second doesn't seem a lot more, so why doesn't it happen on video? Well, as we have already said, video is not just 30 frames/s, but 60 'fields/s'. Each 'field' really represents a 'frame' made up of even or odd lines. If you were to look at one 'field', it would look like someone had closed venitian blinds over the camera, but of course when you display 60 alternating fields all together in one second, it looks like smooth motion. It is this use of 'interlaced' frames that gives video it's 'look'. Ever wondered why when you pause an older VCR, you get that blurred flicker between two images? ... It's because you are seeing two fields at onces, or two 'venitian blind' frames .... One odd, one even .... A 'film' look, on the other hand, is achieved with 'progressive' frames..... Now, before anybody jumps up and down, film is of course generally superior to video due to lenses, lighting, far higher resolution, better contrast, better colour depth, no colour bleeding ... etc , etc, etc.... but I believe the thing which really sets the 'looks' of the two apart is the progressive/interlaced difference. For those of you who follow the home entertainment scene, you may have noticed the more up-market DVD players these days featuring 'progressive frame output' on their list of specs..... Why? ... to get that 'film look' of course. The NTSC MPEG2 DVD standard supports not only 30 frames/s, but also 24 frames/s. So, in the transfer of a film to DVD, there is no telecine process required, therefore no interlacing at all, and when played on a 'progressive output' DVD, you get about as close as you can get to the way it was 'supposed' to look. It'll never compete with the real thing though!

If you're inclined to play around with computers, get your hands on an 'interlaced' DVD (not a movie), pop it in to your DVD-ROM drive and watch it..... It will look different to the way it does on tv, because your DVD player software will
'de-interlace' it. (Computers can't display interlaced video) The motion doesn't look quite as smooth, and the picture doesn't seem as sharp. That's because you are seeing two 'fields' kinda 'blurred' together every 1/30th of a second. Pause it in a scene of high motion and you will see what I mean.

So, when it comes to 'motion' , video leaves 'standard' film for dead .... But film kicks ass everywhere else. Why do they shoot more up-market tv shows on film? ... hmmmm .. I wonder

I hope this all makes sense to everyone, and if I'm wrong ..... feel free to shoot me down in flames ... or is that 'frames'?

Posted by Ray Derrick (Member # 1001) on 01-11-2002, 08:10 AM:

Re Joe's original post, many TV programs, particularly wildlife docos and the like, are shot on super 35 film. So you may ask why go to the expense and inconvenience of using film in the production of programs destined only for electronic media? The answer is that many producers prefer the "look" of film. Pictures from TV cameras tend to have stark contrast, hard edges and exaggerated colour whereas film tends to have a softer look and more realistic colour rendition. When film material is transferred to video in a telecine it does not lose this film "look".

I suspect that when full digital production becomes common with feature movies, someone will come up with an elaborate digital filter process to recapture the "look" of film. Also ever noticed how an actor's makeup is much more obvious in a video production? Somehow a film camera has this knack of making makeup disappear.

------------------
Ray Derrick
President
Panalogic Corporation Pty Limited
44 Carrington Road
Castle Hill NSW 2154 Australia
Phone: 61 (0)2 9894 6655 Fax: 61 (0)2 9894 6935

Posted by Dave Macaulay (Member # 813) on 01-11-2002, 08:32 AM:

Matt: The frame vs field theory only works for acually moving images, yet video and film look different even when showing a still image.

Motion artifacts can be manipulated in both formats by varying the actual exposure time per frame/field, essentially choosing between a "jerky" progression of very sharp images or a less jerky progression of images with motion blur. The perceptual effect is different but neither can really be called better. I agree normal video has less motion artifacts because of the 60 (or 50) images per second. Our minds somehow combine the 2 half-resolution images into a full resolution composite - much like combining the successive images to perceive motion.
The progressive scan system was not enirely for flicker reasons - presenting 60 (or fewer) full frames a second would do that. Progressive scan saves RF bandwidth in transmission (not sure they cared about it then...) and halves the data rate simplifying everything in the chain. 60 fps was picked because much less and the picture is clearly perceived as flickering. Film gets away with 48 because it's not as bright and usually covers more of the visual field, but if you look at the picture with just the edge of your peripheral vision in a bright scene you will see definite flicker.

Increasing the frame rate of film reduces the motion artifacts but both Showscan and Imax HD failed to prosper because the "problem" is so trivial that a solution has to be very low cost to bother with. People are just not bothered by the motion artifacts. A simulator ride with Showscan is more convincing that with 24fps film - but not overwhelmingly. Most people would be just as entertained without the 60fps "reality".

So why does a still image look so different? With Showscan it looks different from a normal 24fps film - more like a slide than a movie, but still "different" from video. A film image seen at 1fps on a Kineton FP30ES with the shutter running at 24fps still looks like film although it is obviously a (relatively) "still" image rather than a movie of a motionless subject.

Probably one could produce a comparison between HDTV and showscan that is almost indistinguishable:
The biggest difference is in contrast range. Film has much more than video - 100:1 at least, video is around 40:1 (HDTV might be a bit better) - this can be masked for comparison by limiting the contrast on the film.

Next is the color space. NTSC has a more limited color space than film because of the limits of phosphors - there are a limited number of phosphor colors compared to dyes for film. The choice made for NTSC has a smaller color gamut than normal color film.
Again, the color space can be constrained on film along with its contrast range or dyes matching the phosphors could be used.

So... if we make a showscan (60fps) film to show (rear projection I suppose) beside an HDTV monitor with 60fps sequential scan, they can (probably) look indistinguishable with any program ONLY if we cripple the film.

I think this contrast & color difference is one big reason for the "video look", not the field/frame rate. The other big one is the way frames are presented, scanning lines onto phosphors that immediately start to fade out vs evenly illuminated images interrupted by the shutter might be a huge perceptual difference and explain why video-to-film doesn't look like video when projected.

This is today. Video will progress to equal film and probably become better. DLP has a better potential contrast range, a less constrained color space, doesn't necessarily scan like a phosphor tube (I don't know how or at what rate the DMD presents pixels), and right now is effectively equal to film quality for showing animated subjects.

Unless "regular" TV abandons the NTSC standards and gives up backward compatibility it will forever be inferior to film, and can probably never equal it with direct view CRT technology.

Oh... to transfer film to video, regardless of the final format, there is always a telecine process. You can call it a film scanner but the process is the same.

Posted by Paul Mayer (Member # 355) on 01-11-2002, 03:51 PM:

Let's see...

Frame/Field Rate: Already been well discussed here.

Resolution: It'll be quite a while before a practical video imager/display/storage medium can match 35mm (or even 16mm) in this regard.

Dynamic Range: Scott already talked about this. Many film stocks have an exposure latitude of seven stops or so, which allows the photographer all kinds of room for creative lighting setups. Only the best EFP (Electronic Film Production) video cameras can approach that. Consequently, lighting for video is more concerned about limiting the contrast range, which can lead to less dynamic looking pictures.

Over-Exposure: Film fails gracefully, even beautifully here. Video ends up looking harsh here due to the action of white clip circuits. Modern-day cameras do have a "soft" clip feature to try to reduce this effect, but generally they are difficult to align (it's hard enough for most guys to get a camera to track grey-scale from 5-95 IRE as it is, let alone the separate controls for that last 95-100).

Response Curve: Beyond just basic gamma, the curves are very different. Film has D Log e response to light--video does not, although the latest Sony EFP cameras do have the ability to store DSP settings (the knee and toe points on the curve) which allow the camera to mimic the look of several popular motion picture film stocks.

Aperture Effect/Detail Enhancement/Noise Coring: All of these are factors that must be dealt with in a native video image. Film (other than managing grain (noise) issues) does not. Video edges, even the best of them, do not have the "effortless edge" look of film.

Lenses: Not directly a film vs. video thing but go along with me here for a bit Even HD video is still pretty low in resolution compared to film. This means the lenses used for video can get away with things (like higher amounts of chromatic aberation or focus tracking error) that would be unacceptable on film. Prime film lenses are fixed focal-length, and film zoom lenses have relatively short zoom ratios (not many over 10:1), all to produce noticably sharper looking pictures with less lens flare. In video, the differences in the sharpness of fixed primes and good zooms are lost at the imager. So you hardly see fixed lenses used in video at all; instead you see relatively long zoom ratios, e.g. 18:1 for handhelds, 32:1 for studio cameras, up to 85:1 (!) for sports. Zoom lenses, having more elements within them, have more flare problems to contend with, and this shows up in the pictures. Differences in lenses also lead to differences in camera technique--i.e. film prefers fixed lenses so camera moves are used more often than zooms; video prefers zoom lenses so zooms are used more than camera moves. This area too is beginning to change with the latest HD EFP cameras like the Sony/Panavision being used on SWII which uses film lenses and is configured to work like a film camera (i.e. tape measuring the focus and use of a 1st AC/focus puller). BTW at one of the SMPTE Hollywood Section meetings it was mentioned that some wag thought the new camera should be called a PanaSony, a name that didn't go over real well with either Sony or Panasonic...

I imagine that these film vs. video differences will get smaller over time.

Cheers!

Paul

Posted by Ray Derrick (Member # 1001) on 01-11-2002, 06:01 PM:

Matt

Your frame vs field theory is good but if it were correct, then surely a film transferred to video would still have flicker on a pan. Doubling the effective "reproduce" frame rate of a motion picture already "recorded" does not result in the interpolation of new frames between the existing frames. This is not some DSP process where software can work out where the in-between image should be to smooth out the motion. The two video fields still reproduce the same static frame of film, and when the next frame comes along, it jumps to the left or right, just as it would from a projector.

I have only ever noticed pan flicker in movie theatres, never on video. Surely this has more to do with the imperfect nature of film projectors than the frame rate.

Another point to consider in all of this, is that film is shot using mechanical apparatus. The film must be pulled down and held motionless for the duration of the exposure of each frame and likewise during projection. Anything physical has mass and when it moves has momentum, so stopping it absolutely dead and in exactly the same spot every time is almost impossible. So there must always be some degree of vertical and horizontal jitter (due to imperfect cameras, processing and projectors) which will affect the look of the image.

By contrast, video does not rely on anything mechanical and is thus always absolutely rock solid, both vertically and horizontally.

------------------
Ray Derrick
President
Panalogic Corporation Pty Limited
44 Carrington Road
Castle Hill NSW 2154 Australia
Phone: 61 (0)2 9894 6655 Fax: 61 (0)2 9894 6935

Posted by Joe Redifer (Member # 3) on 01-11-2002, 06:19 PM:

I have seen strobey pans on video from film transfers. A good example is nearly any science fiction movie that has stars in the background. Both in the theater and the resulting video it seems like you can see two of each star at the same time while the image pans at slow to medium speed. The panning stops and so the the jerkiness/double images. Maybe I am noticing something else?

Posted by Jerry Chase (Member # 660) on 01-11-2002, 06:35 PM:

"I have seen strobey pans on video from film transfers. A good example is nearly any science fiction movie that has stars in the background. Both in the theater and the resulting video it seems like you can see two of each star at the same time while the image pans at slow to medium speed. The panning stops and so the the jerkiness/double images. Maybe I am noticing something else?"

Hmmm. I watched Barbarella and when the panning stopped I still was aware of double images in her chest area and some jerkiness in the acting...

Posted by Paul Mayer (Member # 355) on 01-11-2002, 07:42 PM:

Regarding Ray's notion about pan flicker and frame rate vs. the imperfect nature of projectors, I think that frame rate may actually be more of a factor. True, there's not much difference between 24 and 30 fps, but it certainly is quite noticable on a big screen. Film at 30 fps (29.97 stuff or ToddAO stuff) definitely has that "Showscan" look to it. Enough so that I think most people wouldn't be able to discern the difference between 30 and 60 fps. But there sure is a noticable difference between 24 and 30 fps...

Also, shutter angle has a lot to do with perceived pan flicker. Before chip imagers, video cameras didn't have shutters and therefore created enough motion blurring on fast moving scenes to largely negate visible pan flicker. On a shutter camera you can create more pan flicker (I think the ASC calls it judder) by switching to faster shutter speed (lower shutter angle). The rule of thumb in the ASC Cinematographer Handbook says anything faster than one-half the reciprocal of the frame rate (e.g. 1/50 sec at 24 fps, 1/60 sec at 30 fps) will increase this effect. This also explains Joe's example of a typical SF movie star field. If motion blurring isn't added on the animation stand (or in the CG these days) the judder is more pronounced. Same thing in stop-motion animation--compare Nightmare Before Christmas to almost anything done before it to see how motion blurring improves the apparent smoothness of the animation.

I suppose a wee bit of image weave is a part of the "film look" too. I've noticed in various DLP screenings that things like title or rating cards look like electronic stills, due to the weave being so tightly controlled both mechanically and electronically during transfer.

Hmmm. Regarding Barbarella, I noticed the same effect in Tomb Raider. Need to go back and stretch those blacks a bit so we can do a more thorough analysis of this phenomenom...

Cheers!

Paul
SMPTE Hollywood Section
Unemployed Mercenary film/video projectionist/engineer
"When the money runs out, so does I."

Posted by Leo Enticknap (Member # 534) on 01-14-2002, 04:31 AM:

Re. Matt's field vs. frame theory: What about PAL video, which only runs at 25fps?

Posted by Brian Hogan (Member # 940) on 01-14-2002, 03:00 PM:

well, if ntsc video is approx 30 frames/sec (60 fields/sec)... then pal video should be 25 frames/sec and 50 fields/sec. ahhhh, this takes me back to melany's post about the differance between ntsc and pal ('whats the difference between....?' located in film-yak). good times.

Posted by Ray Derrick (Member # 1001) on 01-15-2002, 05:58 AM:

Leo

The traditional procedure for transferring 24fps film to PAL video is to run the film through the telecine at 25fps, so the film runs slightly fast and 1 frame of film = 1 frame of video.

By contrast, an NTSC transfer has to fit four frames of film into every five frames of video. This is normally achieved by a 3:2 process as follows:

In each set of 5 video frames -

video frame 1, fields 1 & 2 contain film frame 1
video frame 2, field 1 contains film frame 1
video frame 2, field 2 contains film frame 2
video frame 3, field 1 contains film frame 2
video frame 3, field 2 contains film frame 3
video frame 4, fields 1 & 2 contain film frame 3
video frame 5, fields 1 & 2 contain film frame 4

So frames 2 and 3 in each set of 5, have their two fields split between two adjacent film frames.

Therefore the contents of the 20 fields in a sequence of 10 video frames looks like this:

1 1 1 2 2 3 3 3 4 4 5 5 5 6 6 7 7 7 8 8

So every second film frame occupies 1.5 frames of video.

Isn't technology wonderful?

------------------
Ray Derrick
President/Chief Engineer
Panalogic Corporation Sydney, Australia
Phone: 61 (0)2 9894 6655 Fax: 61 (0)2 9894 6935

Posted by Leo Enticknap (Member # 534) on 01-15-2002, 07:33 AM:

Thanks for the explanation. I dread to think what you'd have to do in order to convert material originated on NTSC video to film...

In theory this should mean that the perception of movement on telecine transfers should look a lot smoother on PAL than on NTSC, though (and admittedly, I haven't seen very much NTSC video transferred from film) I can't recall noticing any difference.

Posted by Bob Maar (Member # 763) on 01-15-2002, 08:12 AM:

This is an extremely interesting topic.

However, I believe that the bottom line will come down to who will pay the price at the box office.

I do not believe that the majority of the audience cares whether the medium is film or video. They want to be entertained, they want to forget about their problems for a few hours by watching a show and being engrossed in another world of problems.....somebody else's.

I think that doing film right is a wonderful service that the public appreciates. If you are showing video, do it "right" also.

Both of these mediums are going to have to co-exist for a long period of time. I believe that e-cinema will eventually win the lions share of the market, I also believe that film as an art form will never disappear.

Posted by David Stambaugh (Member # 1102) on 01-15-2002, 11:00 AM:

On a sort of related topic, reviewers of digital projectors and video monitors (talking home theatre now) pay a lot of attention to the ability of the unit to reproduce a good black level. Presumably this is an issue for DLP theatre units. There are quantifiable standards for black and even blacker-than-black. I've noticed that film does not seem to do perfect black very well. For example, "In The Bedroom" has several scene transitions where the screen goes dark for at least 5 seconds. But it is nowhere close to black. It may be very dark, but it isn't black by a long shot. In other words light is still reaching the screen.

So my question is, if film can't do perfect black (or can it?), why is digital video held to a higher standard?

(Where I used to work, we had a JVC/Hughes D-ILA projector in the company's product demo room, and it looked pretty darned good. Don't count out D-ILA. It was for demo'ing video games, but we frequently showed DVDs on it after-hours and it was pretty impressive [but not film].)

------------------
- dave
Crab juice, or Mountain Dew?

Posted by John Pytlak (Member # 331) on 01-15-2002, 03:31 PM:

David asked: "So my question is, if film can't do perfect black (or can it?), why is digital video held to a higher standard?"

Digital Cinema standards are still being developed by the SMPTE DC28 working groups, so there is no "higher standard" today. For film projection, standard SMPTE 196M specifies that "Screen luminance due to stray light shall be less than 0.16% (600:1 theatre screen contrast ratio) for review rooms and primary theatres."

Kodak VISION Premier color print film can achieve densities well above 4.0, which represents over a 10,000:1 brightness range on the film. However, the negative must be well exposed to achieve shadow densities and "blacks" this rich. Often, prints with "smoky" or "milky" blacks are due to underexposure when shooting the camera negative, which is often a deliberate artistic decision on the part of the cinematographer.

Here are data for Kodak VISION Print films:
http://www.kodak.com/US/en/motion/products/lab/2393.shtml
http://www.kodak.com/US/en/motion/products/lab/2383.shtml

FWIW, after a Digital Cinema screening of "Planet of the Apes", I was able to cast a distinct shadow on the screen with the light from the DLP-Cinema projector that was projecting "black", so there's room for improvement.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by John Pytlak (Member # 331) on 01-15-2002, 03:57 PM:

The "film look" is hotly debated on many forums. The Kodak website has quite a bit of information:
http://www.kodak.com/US/en/motion/story/flash.shtml
http://www.kodak.com/US/en/motion/story/fact.shtml
http://www.kodak.com/country/US/en/motion/newsletters/inCamera/july2001/wallis.shtml
http://www.kodak.com/US/en/motion/digital/system.shtml
http://www.kodak.com/US/en/motion/digital/reality.shtml

Posted by Paul Mayer (Member # 355) on 01-15-2002, 04:10 PM:

On a typical size screen for video (or large enough number of screen heights) the difference between PAL and NTSC frame rates isn't all that noticable. Same thing for the difference in scan lines. But get closer to the screen or increase its size and the difference in frame rate becomes quite apparent, ala the 30 vs. 24 fps affect of ToddAO vs. everybody else. The biggest performance tradeoff with PAL vs. NTSC has always been spatial vs. temporal resolution (well, that and not having to mess with a Tint knob when using PAL

). So, slightly more vertical resolution or slightly less flicker? Take your pick.

Yeah film black can be pretty black (what was that process called that left some silver in the print in order to get the blacks more opaque?) CRTs (projection or direct-view) can achieve good blacks as well. LCD and D-ILA still have a ways to go. Same for DLP though not as much--can't wait to see the new black DLP 1920x1080 chips. Other than "make it look like film" I'm not aware of any quantifiable standards for the level of black in a theater application (I'll defer to other SMPTE folks here). Picture black should just barely be discernable from whatever background light level exists in the room. When I do video I insist on having no lights on in the video engineering area. That way when I set the black level on the match monitor I can achieve true beam cutoff for picture black--it don't get any blacker than that. Since there are lights on in the rest of the production facility, the blacks on the monitors in those areas end up being set a little higher.

Hurray to Bob for anchoring this back to the ultimate purpose of our endeavors--entertaining an audience! Now if only the studio suits would greenlight more stories worth telling...

Cheers!

Paul
Workin' on gettin' back to SoCal or Japan

Posted by John Pytlak (Member # 331) on 01-15-2002, 09:50 PM:

Paul Mayer asked: "Yeah film black can be pretty black (what was that process called that left some silver in the print in order to get the blacks more opaque?) "

Technicolor calls it "ENR". Deluxe Labs calls it "CCE" or "ACE". Others call it "bleach bypass" or "silver retention":
http://www.theasc.com/magazine/nov98/soupdujour/pg2.htm

Leaving some silver in a color print image does make the blacks more dense and increase contrast and graininess, along with desaturating colors. One disadvantage is that the silver absorbs infrared energy, making the print more prone to heat damage or focus flutter with very large or misadjusted lamps.

As I noted, Kodak VISION Premier Color Print is capable of over 10,000:1 contrast range in the NORMAL ECP-2D process --- that's REALLY black!

Posted by Ray Derrick (Member # 1001) on 01-15-2002, 10:07 PM:

Actually David, in television they have a curious term "blacker than black". This refers to signals which are more black than normal "video black". The standard PAL TV test pattern has an area in the centre that has a box of video black adjacent to a area of blacker than black which is there to assist in setting the correct brightness level of a TV or video monitor. I don't know if this idea has been carried over to digital cinema, John?

------------------
Ray Derrick
President/Chief Engineer
Panalogic Corporation Sydney, Australia
Phone: 61 (0)2 9894 6655 Fax: 61 (0)2 9894 6935

Posted by John Pytlak (Member # 331) on 01-16-2002, 07:38 AM:

Derrick: The SMPTE NTSC Color Bars have a PLUGE pattern, which stands for "Picture Line-Up Generating Equipment". This pattern, at the bottom and to the right side of the SMPTE bars is used to set the brightness of the monitor. The monitor is adjusted so that the black and blacker than black areas are indistinquishable from each other and the lighter than black area is slightly lighter (the contrast should be at the normal setting):

http://www.gekco.com/vidprmr.htm#SMPTE%20Bars
http://www.mrli.com/gallery/html/smpte.html
http://www.videotek.com/app27.htm
http://www.leaderusa.com/assets/images/ch8.pdf

Smoky blacks in Digital Cinema displays are most likely due to flare in the optics or stray light, which a "blacker than black" signal will not correct. Ideally, if the signal is "black", you should not be able to cast a shadow on the screen. In reality, there is often noticeable light coming through the lens.

Posted by Aaron Haney (Member # 747) on 01-17-2002, 06:10 AM:

Interesting how today's print film stocks can acheive a 10,000:1 contrast range, yet digital cinema manufacturers brag about 1,000:1 as though it were supposed to be impressive.

Posted by John Pytlak (Member # 331) on 01-17-2002, 07:40 AM:

Although the contrast range on the print film itself can exceed 10,000:1, practical projection systems (whether film or digital) are limited by the flare and stray light in the optical path. In general, the simpler optics of film projection normally allow greater contrast range.

The principles outlined in my article on "Conquering Contrast Killers" apply to both film and digital projection:
http://www.kodak.com/US/en/motion/newsletters/reel/december99/pytlak.shtml

The "bottom line" test is whether you can cast a distinct shadow in the "black" areas of the projected image. The "blackness of outer space" is NOT supposed to be dark gray.

Posted by Steve Guttag (Member # 268) on 01-17-2002, 08:34 AM:

An often misunderstood part of the "Brightness" control is that it really sets the BLACK level. The Standard SMPTE color bar patter can have one set the black level a bit too high since the color bars excite the system a bit as compared to a "typical" picture. I find it to be good though if you have a high ambiant light level.

The SMPTE color bar pattern is chalk full of goodies though (kinda like 35-PA is to film)...with a minimal amount of "tools" (an blue filter) one can set color, tint and brightness. As one gets to know the pattern, even the individual colors can be detected to be off.

Steve

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"Old projectionists never die, they just changeover!"

Posted by Paul Mayer (Member # 355) on 01-17-2002, 04:39 PM:

That happens on displays with poor black level retention, which unfortunately means it happens on a lot of displays (Clamp circuits!? We don't need no steenking clamp circuits!). The SMPTE bar pattern has relatively high APL (Average Picture Level) which on poor sets causes the black level to go down. If you set the black level by looking at SMPTE PLUGE on such sets the blacks will be too high on scenes with lower APL. Test discs like Video Essentials and Avia provide several full field PLUGE patterns with different APLs in an attempt to allow for this.

Many people are dissatisfied with the present SMPTE PLUGE pattern--it's in a corner and it's too small. Several years ago I had heard there was a recommendation going around the SMPTE Working Groups to change the pattern. Haven't heard anything about that lately.

Cheers!

Paul
SMPTE Hollywood Section
Workin' on gettin' myself back to SoCal and Japan

Posted by Frank Angel (Member # 248) on 01-17-2002, 11:51 PM:

There is alot to ponder here, but when all is said and done, you can foget all the technical nuances and go right past the display method and to the human who is watching it -- for whatever reason, we LIKE the look of film better than video. Maybe it's because we are organic and so is film, maybe it's because we grew up expecting more exciting stories and images when we were in a theatre than when we watched live television with its obviously limited production values and stars.
The hard fact is, that today, every one of the top Emmy, Golden Globe, People's Choice, etc., winning dramas are shot on FILM. Rather telling when you consider that they are being produced from beginning to their intended final display, in the video domain. Why wouldn't the producers of NYPD BlUE, THE PRACTICE, THE WEST WING, BOSTON PUBLIC, JUDGING AMY....well, you get the picture -- and it's on FILM -- why would they all be shot in the video domain? You can talk all you want about frame rates and interlace and pixals, etc., but it is *us* -- we just like the look of film. We relate to it, we would rather see it than original video. Yes video has no jitter; yes it's rock steady -- maybe that is precisely why we prefer film instead of it -- because the images our eyes see in real life are rarely rock-steady...rock-steady might even seem to us as unnatural. I am sure somewhere down the line someone will do a really interesting doctoral thesis explaining exactly why we want our movies to look like film, with all its flaws, but until then, the reality is *we do* and none of the improvements in video capture, storage or display that have been made in the last few decades seems to have changed that.

When we begin seeing these top programs being created and displayed in the video domain (and I am not saying it will not happen), film will trounce video every time.

Posted by Heyward Garner (Member # 722) on 01-18-2002, 12:42 AM:

Joe, the guy "stephenvv" needs to get his aspect right. 1 : 1.85, that's a hell of a trick.

Posted by Heyward Garner (Member # 722) on 01-18-2002, 12:53 AM:

Also, in conjunction with your second post on the DV forum... I concur entirely. My eye begins to twitch in random spasms should I see bad film in my theatre. On the extremely unfortunate side, I have to work for a corporation who doesn't give a damn about my equipment or me, for that matter. So sometimes shit happens. I am sure I am at fault for some of it, but who's to say for sure. I know that I take up for any damaged or scratched anything that leaves my theatre...