[John Sharaf]

Craig,

I guess this is what makes horse racing!

I started in film, shooting quite a bit of 16mm that was telecined for broadcast on television newsmagazines, so I feel like I have some point of reference, and I feel that HD video shot at 24p does look quite a bit like film when displayed on video screens. The manufacturers have done a good job in imitating the frame rate (exactly) and some include the pulldown (and even variants like “advanced pulldown’), they imitate the gamma curve with various “film looks”, “hyper gamma” and “cine gamma” settings and finally the video “noise” approximates the grain inherent in film, especially in the almost grainless look of the most modern stocks.

I don’t mean to be a contrarian here, but I have to respectfully disagree with your assessment of the success of 24fps HD in looking like film. Technically the only subtle difference is the action of the shutter itself; in the film camera it moves either side to side or top to bottom, whereas in the video camera it captures the frame/field in one fell swoop. I don’t think that this subtle difference is perceptible, especially enough to distinguish the look as not being filmlike.

I think short of a side by side comparison on identical video displays of the same shot on film and HD you could not really state with much authority that they are different, and in fact, were you to do such a test, I think you would find, once and for all, that you were mistaken.

That is not to say that 24p is the be-all and end-all frame rate. You are correct in saying that it is often used because of the ease in which it converts to 25 (for European release) and 30 (for NTSC use). In most cases, the 30fps frame rate is actually a better choice, in that it remains progressive, which all the inherent motion and sharpness benefits over interlaced, and it looks more “filmic” and less “live”. If the bean counters had not had such an influence as the have always had, this might have been the standard frame rate from the beginning of sound film, rather than 24; but financial considerations have and will always have an influence over technical standards.

Finally, if for aesthetic or creative reasons you don’t like the look of video at 24fps, you still have the alternative of shooting on film or shooting video at the 30 frame rate (if you prefer that).

JS

[John Sharaf]

Craig,

The problem is self evident when you view the output of the Cine Alta at 24p on a HD CRT; it flickers like crazy. This is even though the monitor doubles the frequency rate to try and smooth it out. On LCD’s it’s not apparent because it has an even higher refresh rate.

The solution of course is tho add the processing of a 3:2 pull down; this doubles and triples up successive frames and smooths out the motion. This processing is added in the playback deck and takes place when you make downconverts or dubs. In the Panasonic the logic of 24pN is the same as Sony’s to use less storage (in this case precious P2 capacity) and then extrapolate the frames out later in post, or continue to save storage by editing in a 24p timeline. Remember that 24 is only 40% of 60 so that’s the amount of storage you’re saving – that’s a significant amount. In the end of course, if you’re not printing out to a 24p use (like film out or some DVD pressings) at that point you add the “processing” to make it compatible with 59.94 type CRTs.

I hope this helps. Perhaps “flaw” is the wrong word, but I hope you can now see how the processing takes place.

JS

[John Sharaf]

Like I said, if you’re viewing on a monitor without 3:2 pulldown added, then the motion is not accurate and it might studder, jutter or whatever you describe as unpleasant. Only if filmed out and viewed on a motion picture projector at 24fps, where the dual bladed shutter and the effect of persistence of vision in the dark theater would effectively smooth out the motion could you view the proper effect. This is a particular flaw in the method Sony uses in the Cine Alta and the “native” Panasonic formats, such that “processing” must be applied in playback for proper motion display. Of course the alternative of saving storage space has many advantages too.

JS

[John Sharaf]

HD video shot at 24fps and 180 degree shutter with a 3:2 pull down applied should look exactly the same as film shot at the same rate viewed on video after telecine. Are you looking at the HD footage with pull down (from Cine Alta)?

JS

[John Sharaf]

Obviously that’s what Sony hopes, but the reality is that there will never again be a one-camera solution. Remember that Panasonic (and others) are still actively developing new cameras; their 3000 camera for example is a much better solution, and on the market right now, for high end doc and independent feature (non 4K) at a fair price, as long as you’re prepared to buy into P2.

The “ultimate” HD XDCAM, which will offer 24p and AVC-I codec could be 18 months-two years down the line. Sony themselves might improve the F900 by then to protect the high-lowend business, leaving the PRD700 positioned for the cost conscious news folks.

JMHO,

JS

[John Sharaf]

Mark,

This is the $64K question; if it does (and there is still some confusion about this)then it would be an excellent camera choice for someone who works both for CBS (although it looks like only the magazines will be going HD in the near term) and ABC. For those who work only at ABC, the PDW510 is a half price alternative and may prove to be a better choice if ABC ultimately decides to go another non-XDCAM HD solution in 2011.

Another draw back to the PDW700 is that it will not have 24p and will likely be superseded by a version that does and that also will have a more advanced codec like AVC-I in a year or so.

JS

[John Sharaf]

Not really Jim. If you’re talking frame rates, 59.94fps and 29.97fps are two different rates. 59.94fps is used either as a video or live look or as slow mo to be frame-rate-corrected to a 24 or 30fps timeline, yielding either a 2 or 2.5x slowed-down effect. 29.97 is a progressive frame rate that is filmlike without the 3:2 pulldown, and is often used for tape pieces on network news-type shows and for internet or other computer display, where progressive would be better than interlace.

Now in the interlaced world, 59.94 or 60i resembles the video or live look. When an interlace camera (like the Sony F900) shoots at 29.97 it is making its version of progressive, known as PsF (progressive segmented frames) where each of the two fields per frame are identical in space time.

Some editing programs, notably the latest FCP will mix any and all framerates and formats in the timeline.

I think the original question involves digitizing at 60 rather than 30 fps; you can do this in error with Varicam footage because it’s always written at 59.94. The difference is that they’ve created a 59.94 timeline rather than a 29.97 timeline, but if the camera original was shot at 29.97 then it doesn’t really matter as each frame is repeated to make the 60 fields per second and the 30 fps progressive motion is retained.

JS

[John Sharaf]

Panasonic HD tape based cameras (Varicam and HDX) use some of the user bits for flag frames and frame rate metadata. This is required to pull the 24 frames out of the 60 to create a 24fps timeline and the frame rate for use in frame rate correction.

JS

[John Sharaf]

Wayne,

Black Balance daily yes, but auto white balance is a subjective control. Many of us use the presets for more consistent and more colorful pictures and reserve the use of auto white for mixed color source environments and fluorescents.

BTW, a single cycle of ABB will not necessarily erase, or turn off a lit pixel, if it can be done it’s usually after a series of ABB in a row.

JS

[John Sharaf]

Mike,

With many cameras, including Sony’s F900’s, lit pixels can often be removed (masked) by repeated ABB cycles. Try doing this three or four times and the auto masking circuitry should turn off the offending pixel.

JS