After the release of the Nikon D90 with its movie mode, I was checking everyday all the forums to see what is the 'competition' bringing out. Finally the new 5D came with a much anticipated movie mode, but alas at 30fps.
For now I have two points on my wish list:

1. Movies for theatrical release are made in 24fps. TV shows in PAL countries are shot at 25fps.
I know it is possible to convert from 30 to 24 or 25 fps but it is time consuming, not easy and the results are far from perfect. Also, shooting at 30 fps in low available light (fluoro lights, street lighting) in countries with a 50Hz AC current cycle will result in an unpleasant flicker, making the shots totally unusable.
Is it possible in a future firmware upgrade to have options for 24 and 25fps as well? The camera is targeted at a professional level and people like us travel al over the place and have to adapt to the local conditions.

2. A full frame 24x36mm HD video recording is fantastic. Beautiful depth of field or better said, lack of it. But to achieve a HD movie clip where the focus is kept accurately on moving subjects, it is VERY difficult. Every movie production that is shot for theatrical release or TV, the frame size has a diagonal of ~32mm (much smaller than a FF DSLR). A highly trained focus puller is very valuable and impossible to shoot without it (or unheard of).
Would it be possible in a future firmware upgrade to have a one of the 'movie mode' settings cropped at the APS size or even Super 16?

Without these upgrades, RED ONE, SCARLET are still miles in front for digital cinematography, without mentioning RAW image capture as opposed to a heavily compressed codec that will still need a conversion if it will be used for editing.

If Canon is listening, please consider!

Hmm. That's true, but given one or two updates, I'm sure they'll address that in a firmware update.
On the topic of a focal puller... Canon did have contrast AF which is achieved in live view, and in movie mode (correct me if I'm wrong, that's what I think I read)... I dare say that it'll be suitable for most slow moving stuff...

Just to add, it has HDMI, and if it has live view over HDMI, then that will likely make focus and composition a lot easier.

Regarding focusing when using the camera as ENG tool, I find it very difficult to have a smooth rack focus acceptable for broadcast or theatrical release with the in-built autofocus funtions. Even with proper cine manual lenses this is quite difficult at 35mm FF sensor size (I shot a lot of documentaries with ARRI 2C cameras). The higher DOF provided by 2/3" chips of the ENG cameras make them easier to use.

In my photojournalistic work, I am using 1DMk3, and also have a small TX1 camcorder for video aquisition, that is used only at VGA resolution. I'd love to have one that gives a better image quality in low light situations and Panasonic LX3 fits the bill better at this stage.

My hopes for this 5DMk2 model were for the possibility of using it in shooting drama, as I have a film in prep stage and we are still open to consider various digital capture formats for our small budget (including SI1920 or RED).

Nikon D90, due to be released tomorrow here in Oz, with its 24fps capture and if it confirms that the AE exposure can be locked, will be a strong contender. Carefully planning each shot, I think the rolling shutter issue can be kept under control, and the manual focus lenses from Nikon are a better option (although they can be used on Canon EOS bodies with adapters).

The quality of video playback can be problematical. You need the right equipment and software. I believe that most modern TVs/Plasmas/Projectors can handle all sorts of different standards, NTSC, PAL, 50Hz, 24HZ, 30Hz, 60Hz, 100Hz, 3:2 pull down etc.

If the performance of the currently available video samples is anything to go by, there must be a lot of people who are disappointed at the results so far. This seems to be a new ball game.

The 5D2 movie samples I've downloaded so far are in Quicktime format. My Win64 bit computer is set to use Windows Media Player by default. However, the contrast is too great and the shadows too dark on my calibrated monitor. There also seems to be strong jaggies despite the clip being HD. And the file size certainly suggests it's HD at over 282MB.

Opening the file with the Quicktime player installed on the same computer produces better color and much better shadows, and the jaggies are no longer so obvious. However, motion is unacceptably stuttery and jerky.

These sample movies are simply not properly playable on my computer. What the heck's going on?

I tried changing the refresh rate of my monitor from 70Hz to 60Hz (1800x1440) thinking that 60Hz would fit in more easily with 30fps, but it made no difference.

Hey Pix,

I appreciate your wish for a $3000.00 camera to make a theatrical drama!

I don't think a camera designed for still photography will fit the bill though. Auto focus lenses will never work for narrative filmmaking as they don't know who to focus on, even if they can track focus that well. And auto focus lenses don't lend themselves to manual follow focus. And neither do old manual focus SLR lenses as the distance scale is much too compact. So if you want to shoot movies of moving objects with your 5dII, you'll have to stop down a short focal length lens.

Why not try something like a panasonic HVX camera. I've seen movies shot with this camera projected on a very large screen and it looked quite good. It even includes a zoom lens and shoots at your desired frame rate. And there's no problem with a rolling shutter either. And it records in a format that is easy to edit too.

Sounds like codec issues to me. Try playing the movies with another player such as VLC. I generally find that many issues disappear when I play with VLC instead of Quicktime. (On my Mac this is).

http://www.videolan.org/vlc/

Re Focus. Cant you attach an extension handle to existing manual focus lenses and pull focus manually?

I bet a lot of historical cameramen had to do this. Assuming the camera is mounted on a suitable tripod/head, obviously harder to do hand-held.

I've downloaded all the optional software and hardware updates from Microsoft, yet the latest Media Player 11 (or Quicktime) cannot fully handle these sample 5D2 videos on my WinXP 64bit system with Matrox PCI video card and 6GB of RAM.

I've just tried VLC as you recommended, and that's even worse. I get no motion at all. Just a still image.

However, I copied these video samples to a USB memory stick and tried playing them on my Dell laptop with Windows Vista Ultimate. No problem at all. Smooth, natural and HD video at the slightly reduced resolution of my laptop screen.

This is looking encouraging. Last time I went trekking in Nepal, in addition to a 5D and 20D, I took a Sony T30 P&S with me, mainly to shoot footage of Nepalese folk dancing in the villages and traditional dance shows in the restaurants. The results were rather disappointing. Nowhere near professional standard definition quality. Shadows rather noisy, resolution a bit mushy.

A 5D MkII should suit me fine .

Regarding choice of lenses. as mentioned in my previous post, I will never try to use an autofocus lens. Older, non AI Nikon mount lenses would be one of the very few options for such a project if shot with a DSLR. The focus ring turns more than 180 degrees for full scale, as opposed to the modern ones that have a full scale less than 90 degrees.
There are adapter rings for 32 pitch follow focus devices (Red Rock Micro makes pretty good ones). Please note that even RED ONE camera has an option for Nikon F mount.
Unfortunatelly, 30fps, inter-frame compression codec used by the EOS 5DMk2 is a no go for now: a post production nightmare where the conversion to 24 or 25fps looks bad - with very strange motion artifacts, a.s.o.

The HVX is a fine camera but the DOF coming from a 1/3" chip is not what we are after.

Pix, I know you won't believe this , but, from my experience, short depth of focus is not what makes cinematography look good.

The most important factor is what is put in front of the lens to photograph. Good actors, good costumes, good set, good lighting, good composition. After all that, I would consider depth of focus, but don't get fixated on the size of the chip. As you pointed out earlier, it's hard to shoot a movie in focus with moving actors and very short depth of field. Even for the professionals. Really, will your professional focus puller be using an ultrasonic tape measure during shots to help nail the focus? Even with that, sometimes an operator has to try to fix it on the fly if they can see it.

Personally, I don't like movies that are largely "almost focused", but I've seen a few shot with 35mm still camera lenses (or cine lenses) on a Red Rock or other 35mm lens adapter. I think the movie has to be pretty darned good to overcome being out of focus 85% of the time.

I seem to remember a lot of buzz about a cinematographer who managed to shoot an entire motion picture with everything in focus. Magazine articles were written about this great achievement from 1940 which of course was "Citizen Cane".

Pix, just so you know, I'm not really answering your post directly, I'm really reacting to all the people who insist to me that "we can't afford to shoot on 35mm film, so we need to use one of these Red Rock adapters to make the movie look good like film" "Here, we can use this handycam (choose model/brand) with adapter and our $5000.00 feature film will look like we used a Panaflex and spent $20,000,000!"

Really worse than this are those that say "ok, were stuck with a 1//3 in or 2/3in chip depth of field so we'll shoot everything on the longest lens we've got to get that background out of focus. Then it will look like a real movie". No, it just takes the viewer out of the action like they're watching the story on a telescope.

Rant over. Pix, make a great movie!

I'm just hoping for a quick and easy 24P firmware update for the 5D2. It will make the camera more "complete" IMO. Right now, I look at the 5D2 and say, wow, it's such an awesome camera, but why, why, why 30P!?

Supposedly the RED DSMC camera specs will be announced at the end of this year. That means I'm not going to buy a thing from Canon and Nikon until maybe after Christmas, unless the RED is more attractive.

Because 30fps fits nicely into the NTSC 60Hz system which is a consequence of the American 60Hz AC electricity supply system. For judder-free images, an unmodified 24fps is not sufficient. Whilst movies may be shot at 24fps, playback always requires an effective doubling or tripling of that frame rate. I believe a modern movie projector employs a system whereby each of the 24 frames in one second of footage is flashed 3 times before the next frame is dispayed. We have in effect a 72Hz refresh rate which tricks the eye into a sensation of smooth motion.

Playing a movie shot at 24fps on the 60Hz NTSC system requires a complicated process called 3:2 pull down. How do you get 24 to fit into 60?

30fps has its advantages.

no 24p??

Why 24p??

We tend to put all of these cameras into categories designed for past think.

35mm still cameras for action, larger still cameras for static images, video cameras for eng and home movies, cinema film cameras for high end production and theatrical.

All of this is merging and the web is the common denominator and allows for multi media and viewer interaction that traditional broadcast and print can't come close to.

Step back for a moment and think what the role of a visual artist is because regardless of the medium, we're entertainment producers.

Our role should produce work that makes people stop, look and hopefully enjoy, not just keep playing the same old predictable tune.

It's somewhat funny to me that these forums have people comparing images on the sub atomic pixel level, beating each other over the head about what brand, format, lens is the absolute best, without a single mention of why any artist would think of purchasing a new camera. . . which to me is "will this camera let me do what I couldn't do before?".

I think the 5dII does that and in fact I can see so many possibilities with a camera that can shoot a high quality still and any form of motion with the same pov and framing it amazes me. At the price it's almost laughable. Had this camera come out 5 years ago it probably would be $50,000.

Is it perfect . . . no and of course no one is going to shoot their next cinema feature with a 5d, though a lot of artists with talent will take this camera and do something very interesting.

Today since the western economies have tightened up, there is a contraction of creative approval. It's a natural tendency to play it safe. Getting a new or even close to ground breaking concept through the chain of command is very difficult.

Comparatively look east and see what is being shown in China, Japan, Korea. It's more than interesting and gives a look into what is possible and where a camera like the 5d can allow you to produce imagery that would be 4x's more complicated using traditional cameras.

http://www.levi.com.hk/

JR

Hear, hear. I can't wait to try this out and find out where the boundaries are.

As its the first release I imagine a lot of the issues about video output and standards will be refined in future firmware releases and in successor products.

Laforet:

http://tinyurl.com/4oc8je

Looks like the 5D2 could be the best selling full frame DSLR in the history of mankind .

I thought maybe this Christmas might prove to be expensive. However, I expect the pre-orders for this camera will be so huge, I'll stand no chance of getting one for Christmas 2008. Maybe Christmas 2009.

Any decent HDTV capable of 1080P can refresh the screen at either frame rate--the engineering reasons for linking the vertical scan frequency to the power supply frequency have been obsolete for several generations of CRT-based TVs. Note that computer monitors have offered a fairly wide range of vertical refresh rates for quite some time now...

But not necessarily in a high quality manner, Jonathan. Video enthusiast have and do spend thousands of dollars on additional equipment to take care of conversion that is seamless and natural, and if they no longer do this, they are still very aware of these conversion issues when selecting a display or projector. LSI chips have traditionally done a better job than software, but whichever system you have, 30fps progressive represents more data than 24fps progressive and therefore has potentially higher quality.

There seems to be a misconception that 24p is better than other systems because that's the frame rate of traditional, filmic movies. However, as Jame Russell has implied, there's no need to be bound by traditional methods of doing things. We're into a new era. The 5D2 is not designed or intended as a tool for converting 24fps filmic movies into a 50Hz, 60Hz, 100Hz or 120Hz refresh rates. It takes it's own movies at a higher frame rate than a filmic movie camera and is better in that respect.

For anyone who is still confused about the significance of 24p, I'll offer my opinion which can be read by those who have not put me on their 'ignore' list.

For digital videocams and general video recording devices, the significance is in the 'P', not the 24, except in so far as the 24p standard may lend itself to the in-built algorithms of certain displays which incorporate convoluted methods of converting the traditional film movie standard of 24fps into the electronic display standard of 60Hz, in the case of NTSC.

Converting 24fps movies into PAL has always been easier than for NTSC. One simply speeds up the movie almost imperceptibly to 25fps, then one doubles the frame rate to 50Hz, and Viola!

The downside with PAL is that sound can also be speeded up (without software to counteract that) so that those who have a sense of absolute pitch feel a bit uncomfortable. But I guess most people wouldn't notice the slightly higher pitch.

Generally, 30p is better than 24p, just as 50p would be better than 30p and 60p would be even better. P for progressive is generally better than i for interlaced.

The interesting thing about the video from the 5D2 is that each of the 30 frames per second is comprised of 1920x1080 fairly large pixels of 6.4 microns. If one were to construct a sensor that could hold 1920x1080 6.4 micron photosites, it would have to be around 12.3mm x 6.9mm in dimension. That's much larger than most (and probably all) consumer grade videocams. Small P&S digicams with video capability have a sensor size of around 5.4mmx4mm. More professional videocams have a sensor size of around 8.8mmx6.6mm (2/3" format).

The 5D2, seems to be very competitve regarding video quality, especially considering the low noise circuitry built into Canon sensors. P&S digicams and consumer grade videocams do not, I believe, have specialised pre-amplifiers at each photosite. Correct me if I'm wrong.

This camera is going to be difficult to resist for a spiritual person such as myself .

You've completely missed the point. Display designs have long since progressed past the point where their refresh rate is tied to the AC power frequency. When the display can natively offer a variety of vertical refresh rates, there is no frame rate conversion involved. I have a HDTV that can display 1080p at either 24 or 30 frames per second. It does so by altering the vertical scan rate of the LCD. There is no 3:2 telecine or frame doubling or any other frame rate conversion going on, it simply changes the frequency of the clock that drives the LCD refresh circuit so that the frame rate of the display matches that of the source video. As a result, there are no interlacing artifacts, and pans are smooth when viewing both 24p and 30p video.

I don't believe I've missed the point. It has always been possible with modern technology to convert different systems to different refresh rates with greater or lesser success depending on the sophistication of the equipment. Of course, in this modern age, refresh rates are not tied to the AC power frequency, although that was built into the NTSC and PAL TV systems when they were first developed.

The point I'm making is that 24p is unwatchable as 24p. It's stuttery just like very old movies projected on old equipment. It has to be upgraded (converted) to a higher refresh rate, say 60Hz as a minimum. However, high end LCD TV displays now boast refresh rates of 100Hz which is what my 10 year old, standard definition CRT PAL TV also uses.

If it's necessary to convert the frame rate of video footage to a higher frame rate for the sake of smooth motion, then its better to start off with 30p rather than 24p.

If I've got that wrong, please be specific.

24p is not stuttery when played back on a display that actually plays at 24p. It's only stuttery when played back on a display that is refreshing at a rate not evenly divisible by 24 and some frames are displayed for a longer period of time than others. If each frame is not displayed for the same length of time, the video will be stuttery regardless of whether it is 24p or 30p.

Ray, I'm going to have to take issue with your major point here. Even for a spiritual person, it takes more than than to create a Viola, as Stradivari, Amati, et al could tell you.

Or, perhaps you meant "Voila?"

Johnathan,
I've never seen a display with a 24Hz refresh rate. You know enough about monitors to realize that LCDs have a minimum refresh rate of 60 Hz and that a flicker-free CRT, such as the Sony Multiscan G400 that I'm using as I write this, needs a minimum refresh rate of 70Hz otherwise it's a strain on the eyes. What's the matter with you?

Perhaps you misunderstand what 24p means. It refers to a display rate of 24 frames per second in a progressive mode as opposed to an interlaced mode.
When you watch a 24p movie on a display that can handle 24p material, each of the 24 frames is multiplied a few times to fit in with the refresh rate of the display.

A standard movie projector in the cinema will display each frame 3x in order to smooth out the stuttery effect. 30fps is less stuttery than 24fps and 60fps is less stuttery than 48fps.

That's a perfectly logical train of thought, Eric. Frames per second, Hz, sound frequency, hi fi, music, viola.

Announcement of a Vincent Laforet movie shot with the 5dII.

http://www.dpreview.com/news/0809/08092101...eteos5dmkii.asp

Right back at you. A CRT has to have a high refresh rate because the phosphors in the tube emit a very short burst of light as the electron beam strikes them, and then quickly fade back to black. Any given pixel on the screen is lit less much less than 100% of the time. If you use a fast shutter speed to photograph a CRT screen (1/120 or faster) you will see a horizontal black band on the screen that follows in the wake of the beam--at any given instant, a large portion of the screen is completely dark. As a result, a CRT monitor requires a high vertical scan rate (>60 Hz) for our eyes to blend the flashing pixels into a smooth continuous image.

In contrast, one of the engineering challenges of designing LCD displays has been to make a pixel that can react fast enough to meaningfully display higher frame rates. Unlike a CRT, an LCD pixel does not fade to black between scans--it continuously displays a color until the next frame arrives, and then it fades fairly smoothly from the old color value to the new one. How long this process takes is defined by the response time of the LCD. The response time of the LCD also limits the maximum frame rate the LCD can display. A high-speed photograph of an LCD display will not show any black band in the image the way a CRT will. Each pixel is illuminated 100% of the time.

A true 24p HDTV may overscan at some multiple of 24 Hz (probably 120 Hz, since that divides evenly into both 24 and 30 Hz) to reduce the transition time from one frame to the next, but that has nothing to do with the high refresh rate needed by a CRT. While a CRT scanning at 120 Hz is flashing each 24p frame 5 times, a 24p LCD simply displays each frame for approximately 1/24th of a second. The LCD is not "flashing each frame multiple times" even if its internal scan rate is a multiple of 24 Hz. Each displayed frame smoothly fades to the next frame over a time interval determined by the response time of the LCD and its internal scan rate.

Here's an experiment for you to try:
Go to an electronics store that has a variety of plasma, CRT, and LCD displays--monitors, TV's, and HDTVs. Bring a DSLR with a fast lens. With the shutter speed at 1/1000 or faster, max ISO, and the lens wide open, photograph as many different displays as you can. Have the camera in portrait orientation so that the shutter curtains are traveling 90 degrees to refresh of the screen image. Make a note of which displays exhibit banding in the captured images, and see if there is any correlation to the perception of smoothness or flicker in the displayed video. Post your results.

Here are some useful links that may explain some of the problems with the new technnology
http://dvxuser.com/jason/CMOS-CCD/ - rolling shutters - why thery are bad.
Video to demostrate the effects - http://www.ssontech.com/content/skool.mov
A discussion by filmakers, not photographers on 30fps being bad.
http://prolost.blogspot.com/2008/09/so-close-canon.html

It's sort of been mentioned above but Vincent LaFloret's blog about actually using a 5DII to make a video and the discusion after is well worth reading. Bar all the repetitive comments about hosting.
Vincent absolutely loves the camera, but has never shot video before. So it's a very different story to those who know more about filmmaking/videoing, but may be resistant to change or know the problems that Vincent has yet to meet.

Dear me! There does seem to be a lot of confusion about the benefits of 24p.

I quickly skimmed through the comments in your linked thread and I could find no explanation as to why 24p could be better than 30p other than a possible frustration at a lack of equipment to handle 30p.

The point doesn't have to be laboured, if you don't have a display capable of accepting a 30p format, then it has to be converted to another format that the display can accept. If you also don't have the software or hardware to perform such conversion, then obviously you're in trouble.

However, as Jonathan has pointed out, whether it's 24p or 30p, most modern displays will accept both and both will look very similar because neither is displayed at a rate of 24 or 30 fps.

There's nothing magical about 24p, except that it's better than 24i. Filmic movies in the cinema are never displayed at 24 fps, but usually 72 fps. Each frame is displayed 3x.

It is possible, however, that some people will make a virtue out of a fault. 24fps is well below the flicker-free threshold. It lends itself to a slightly stuttery effect, more so than 30p. It's possible that a slight imperfection regarding smoothness of motion will trigger a nostalgia effect. Early movie projectors actually did project frames at 24fps.

Such as

!!??
And what are 'filmic movies'?



Actually it was 18fps as base rate, though it could be varied for effect and 16fps is minimal level for flicker free images [for humans].
Though why lets bothersome facts get in the way.
And if 24p give a certain look, that people like for what ever reason, let them use it.


This from the comments as to what has been feature requested from Canon in the blog I linked.
"1. Offer the option of 29.97 and 25.00 fps instead of just 30.00, because when you import any frame rate that's not exact as expected in an NTSC or PAL timeline, the video editors usually resample (instead of re-timing) and this creates ghosting in the final. Only Vegas has a manual way, and AE through a plugin, to fix this -- other editors don't. So this 30.00 is a dangerous option to have for editing, especially as most people don't know about this.

2. Offer 24.00 (film) and 23.976 (IVTC film) as options too. I specifically told him that these frame rates are very important to indie filmmakers and without them none of them would consider this product.

Jonathan,
That's broadly my understanding of the differences between CRT and LCD also. We both know that LCD monitors that are used for still image processing need not have a fast response time. For moving images they do. This has always, until recently, been a disadvantage of the LCD for moving images with fast action, particularly sports. Early LCD displays used to have a falling response time of 15 or 20 milliseconds. I believe they are now as low as 3 or 4 milliseconds.

But you can't have it both ways. A sluggish response time would certainly counteract and blur a stuttery effect. However, an extremely fast response time will have the opposite effect; will accentuate the jerkyness.

I'm not aware of any display that is operating at a refreh rate of 24 fps. Can you point me to a link that explains how this occurs and what the benefits are? As I've already mentioned, even a movie projector in the cinema projects those frames at a rate of 72 fps. If the LCD display holds each of those frames for close to 1/24th of a second, the eye will detect the abrupt change to the next frame. If the liquid crystals have a persistence that smooths the transition, then that's not good for fast action. You get the trailing effect of a poor response time.

Movies recorded on old-fashioned film. (Hey! Couldn't you work that out ).



It might well have been 18 fps in early technology. Before we had motor cars we used to ride on horses. That's not relevant. But I am surprised at your statement that 16 frames per second is the minimum for a flicker-free image. I've never heard of such a thing. Can you point me to some authoritative source where this is stated?



And I can't play either 24p or 30p satisfactorily on my WinXP 64 bit system using the latest Windows Media Player, but I don't whinge about it. There's clearly something wrong, missing or incompatible in my 64 bit system, but my Vista Ultimate O/S on my laptop handles both formats fine so there's no problem.

"Please Mr Canon give me a frame rate of 29.97 because my video editor can't do a good job." I mean, how ridiculous is that? Talk about the tail wagging the dog!!

A film projector has the same problem as a CRT monitor--the frame must be blacked out while the film is advancing from one frame to the next. This means that the image is not constantly being displayed, but is flashing on and off. The shutter is simply cycled multiple times per frame so that the flash frequency is too high to be perceived as a flicker. With a 24p LCD HDTV, there is no flicker to disguise--each frame is displayed continuously, fading into the next frame without a flicker-causing transition to black between frames. The only effect the internal refresh rate has on the displayed image is to affect how long the display takes to transition from one frame to the next.

Fading into the next frame...?? Sounds like that would be just fine for a slow moving rustic scene and a gentle breeze. However, you can't have any fading from one frame to the next during fast action. Even though those liquid crystals remain illuminated to some degree all the time, that illumination has to be low in a high quality LCD display suitable for movies, otherwise the contrast ratio would be too poor.

It seems to me, whether or not there is a total momentary black-out between each frame, there has to be a sudden transition from one image to the next during even moderate movement.

But let's for a moment suppose you are right. What advantage does 24p have over 30p? This is the only reason I got into this thread because I got the impression that some people think that 24p is a better frame rate. It's certainly not better for PAL countries. Canon HD videocams like the HV20 that do 24p in America, do 25p in Australia and Europe because PAL is a 50Hz system.

Ray (and others who are interested), let me help you a little in understanding why the 24fps from cinema cameras are not a coincidence at all and why it still matters at what frame rate we view movies.

A long time back in filming history it was experimentally determined that movement could be shown smoothly using 19 frames per second. Many silent films are shot using that speed. Played at modern 24fps these all look like "funnies", but at the time they came out they looked "normal". Now one may wonder why a speed of 24fps was chosen later. After all it would only cost more film while actual motion smoothness wasn't helped significantly. It so happened that by doing experiments it was discovered that a light flicker rate of 48Hz had a strong effect on people looking at it. They seemed to be more open to the emotional storyline of the movies they were watching, which made going to the movies a much stronger experience. Why this was the case was not known at the time, but it made the "dream industry" settle for 24fps, each frame projected two times (not three!) so the flicker rate was 48Hz. Only later on it was determined that the human brain has a strong tendency to sync to light impulses. It so happens that 48Hz is the typical rate of alpha waves in the brain: the very same waves that can be measured when we are dreaming... And yes, even looking at a white screen with a 48Hz flicker will open up your deeper feelings. ("Saturday night at the movies, who cares what picture you see?" as the song goes.)

Do I need to go on or can you do the extrapolation of using other flicker rates than 48Hz yourself?

Sounds impressive, EDp, almost convincing, except you seem to have a few statements which don't accord with purported facts that are easily accessible on the net. Can you quote your sources?

A quick Google search produced the following, from
http://www.web-us.com/brainwavesfunction.htm



The frequency of alpha waves are even slower than 24fps, never mind doubling to 48fps. The fastest waves are beta waves, up to 40Hz, characteristic of a person engaged in strong debate, such as taking on the President or Prime Minister in parliament. Is this the state of average movie goers, lounging in their comfortable seats in the theatre?



You are right, however, that a mere doubling of the 24 fps to 48 fps is often used for filmic movies. But 72 fps is sometimes used and I guess could be considered more hi tech.

jjj,
To get back to this issue, could you please check your facts first, otherwise you are in danger of misleading folks.

This is what Wikipedia has to say on the matter.



This not the same as claiming that 16 fps is flicker-free. There is a huge gulf between a perception of motion and a flicker-free perception of motion.

Just in case anyone reading this is interested in getting technical, there's an interesting discussion I came across doing a Google search, which addresses this issue of exactly how 24p footage is handled on a modern LCD display.

http://www.avsforum.com/avs-vb/showthread.php?t=832822

No-one seems to know, but there's lots of speculation. This thread from last year, ends with the question along the lines, 'do we have any TVs that display true 24p (presumably at 24Hz)?'

The latest LCD TV displays mostly have a fixed refresh rate of 100Hz and 120Hz, but precisely how 24p footage is displayed seems to be a secret.

It's a subject which I'm interested in because in the near future I will probably succumb to the lure of an HDTV set. Australia will also soon stop broadcasting standard analog definition. I'm totally undecided whether to get an LCD, Plasma or projector. At the moment, the newly announced Epson TW-5000 (7500 in the US) looks very appealing on paper.

Oh! I almost forgot. I'll also need an HDTV display to get the most out of my 5D2

Ray and Jonathan,

I think you're both right.24fps does flicker---when shown on analog equipment or crt display at 24fps. So does 30fps. That's why interlacing works on CRT displays it essentially turns 25fps into 50fps (by showing 50 1/2 frames per second). I'm used to NTSC which is 60 1/2 frames per second and when I view PAL at 50, I see flicker until I'm used to it.

But the point is that an LCD does not redraw the whole frame by blacking out and showing a whole new frame every 1/24th sec. It just changes pixels that change every 1/24th sec. And the pixels stay lit almost all the time, ie. they are not black 1/2 the time. So there is no flicker at 24fps. There is motion judder though. These new LCD tv's with 120hz refresh rate are interpolating frames and inserting them to eliminate motion judder. Most filmmakers would rather their viewers turn off this feature and watch at 24fps without adding pulldown and additional frames. Actually they don't care as long as the dvd is paid for

I have 24 fps video on my web site. It does not flicker on my LCD display. It shouldn't, I don't think there is a "refresh rate" for LCD displays. On my CRT display it plays at 24fps even though my CRT is set to 80hz and refreshes 80 times per second. It doesn't flicker there either, and it saves bandwidth, allowing a higher quality picture using the same data rate. than 30fps.

Jonathan,
Despite a lot of Google research, I haven't yet come across any displays that actually play at 24fps. Are you sure you know what you are talking about?

There's an interesting article that explains the issues at http://hometheatermag.com/gearworks/707gear/

and another article which lists all (or most) of the LCD displays that support 24p, at http://forums.highdefdigest.com/home-theat...frame-rate.html

Almost all of them are 120Hz models and apply a system called 5:5 pull down, but a very few have a 48Hz refresh rate, which seems oddly specialised.

As far as I understand, all LCDs have a refresh rate. It's usually 60Hz in the case of PC desktop displays, and 100Hz or 120Hz in the case of high-end HD LCD displays.

After some research on the net, I can find no reference to any LCD display with a 24Hz refresh rate. The closest is 48Hz. I can only presume that a refresh rate of 24Hz would be unacceptable with 24p material, whether due to motion blur or judder.

If the 24p source is not an even multiple of the refresh rate, then some fancy processing and conversion has to be applied to prevent obvious artifacts, blur and judder etc.

As I mentioned before, my Sony CRT desktop monitor run by a Win XP64 bit O/S cannot display either 24p or 30p correctly, but my Windows Vista laptop can with no problem.

WTF are you smoking??? Let me break the process down into simple steps, using only small words.

At 24 FPS, each frame's display time is 41.667 milliseconds.

Let's pretend the display has a response time of 5 milliseconds.

For 36.667 milliseconds or so, the frame is displayed continuously on the LCD screen, regardless of the internal overscan rate of the LCD panel. At no time during this time period do the screen pixels fade to black.

For the next 5 milliseconds, the screen fades to the next frame. It does not at any time fade to black. The effect from the viewer's perspective is like the new frame being overlaid over the old frame with gradually increasing opacity until the new frame has completely replaced the old frame at the end of the 5-millisecond response time period.

The new frame is displayed for 36.667 milliseconds...

And the cycle continues.

Depending on the particular display, you may be able to observe some refresh artifacts if you photograph the screen at very high shutter speeds. On my 52" Sanyo HDTV, random square portions of the screen will be somewhat dimmer and have a yellowish tint when I use shutter speeds faster than 1/500 or so. But below 1/500, these refresh artifacts disappear and the image appears seamless and even across the entire screen. Most importantly, at no point in the refresh cycle does any portion of the screen fade to black. So while there is a certain degree of high-frequency fluctuation in each pixel's output level due to the refresh process, the process of displaying each frame and transitioning from one frame to the next is fundamentally as described above.

Let me try to break through some of the mumbo jumbo and apparent confusion in your mind.

24 frames per second doesn't work as 24fps. It's not acceptable quality. If footage is recorded at 24 frames per second, it's never played back at 24 frames per second, as far as I can tell. Correct me if I'm wrong. It's played back at a minimum of 48 frames per second, and on the most modern LCD displays at 120 frames per second.

A similar situation applies to 30p, except that 30 fps is at least to some degree better than 24p, and doubling that 30p frame rate to 60fps is smoother (or has less blur motion) than 48 fps.

My initial post in this thread was an attempt to explain to someone who was asking "Why, why, why 30p?" as though 24p was in some way inherently better.

I can find no reason why 24p should be inherently better than 30p, or in the final analysis even as good.

Also, I can find nothing in your posts on this topic that even alludes to any advantage of 24p.

I'll just add a further note of clarfication because we are not entirely at cross purposes, although it might seem that way. I understand your point that flicker is largely a property of CRTs and Plasma displays, and that, whilst a refresh rate of 24fps on a CRT would be horrendous, on an LCD display it would not necessarily be too bad because the transition to a different frame every 24th of a second does not involve a momentary reversion to black.

The only point I have ever been trying to get across in this discussion, a point which seems to have escaped you, is that 24 fps is not enough for totally smooth and realistic motion. 30fps may also not be enough, but it's better than 24 fps and also lends itself more easily to display on a 60Hz system.

24p is just a paradigm of modern cinema film making.... it's a convergence of acceptable cadence and length of film footage shot per roll.... a basic industry efficiency. That's all. Today... we can shoot DIGITALLY at other FPS and get away with them being wrapped in various wrappers using various codecs.

I own and use a sony xdcam ex1 that will shoot 1080 24p & 30p... also 720 24p, 30p, & 60p.... I only shoot 1080 24p (unless I'm shooting slowmo and use 720 60p... slowed down to 30p in post) because it allows for the most efficient use of the 35mb per second bandwidth. the resulting video is less compressed per frame than 30p, and higher rez than 720p.

When I play the 1080 24p footage on my macpro + 30" acd.... it does not judder or stutter. it looks fantastic. When I convert the footage to appletv spec and play it on my appletv/1080p projector.... it still looks fantastic. If I burn a 1080 24p BR disk and play the footage through a BR player... guess what? it looks fantastic.... just like a theatrical release in 24p!

note; fake 24p from interlaced cameras can appear to be stuttery and juddery.

note B; personally... I'm very bummed that the 5d2 is 1080i. ( per Michael's review ) I'm hoping he has made an error.

I noticed that too. Since Michael was handed the 5D2 just a couple of days before departing for Botswana, I guess we can forgive him for that slight error .



Well, there you are! You've hit the nail on the head . The advantages of 24P. It saves bandwidth.

With proper processing, the inhernet advantages of 30p with its greater data throughput is probably undiscernible by all but the most dedicated viophile.

Ray, I have a BA from one of the best film schools in the world. This was part of our "fysiology and film" lessons. I do not use the internet to find support for what was taught to me. This information was presented to us by a scientist who was specialized in this kind of research. I have no reason to believe he was wrong. But feel free to believe whatever you like.

The only belief system I operate on is that every specialist can be wrong some of the time, or can later proved to be wrong as scientific knowledge progresses.

You could be making a mistake if you think that everything you were taught at school is correct.

I merely asked you for your sources. Give me a link to the views of the scientist who taught you, so I can make up my own mind as to his reliability, if his opinions differ from other authorities.

Edit: this what Wikipedia also has to say on the subject of Alpha waves.

I don't recall you ever believing anything anyone else says, no matter what.

But I do agree with this.