One thing I don't understand
 

I read that JVC GY-110/200 is designed and made for 24p and most favored by filmmakers who inverse telecine the footage to 35 mm film. But I know this camera is HDV-1 standard which is 720 vertical pixels, much less resolution than 1080. Why that much reduction in resolution can make this camera be best for filmmaking?

The JVC camera records in progressive scan, similar to the way a film camera records the image to a film frame. This means you see all 720 lines every frame.
The Sony and Canon cameras use interlaced frames, which means at any given moment you a field 540 lines which is very closely followed by the second field of the 540 interlaced lines to make up a frame. This system is used by television for more efficient transmission purposes.
Progressive scan is necessary for a film out transfer so this makes the progressive scan of JVC (Panasonic HVX200) cameras ideal. Progressive scan images are easily converted to interlace for transmission purposes. Converting interlace to progressive is not so simple and in camera options are very much a compromise.
Most modern flat screen monitors (LCD or Plasma), computer monitors and digital video projectors are natively progressive scan, so also suited to the progressive frame system.
It's difficult to see a difference in resolution with your eye when viewing the two different formats. If you intend to shoot mainly for television transmission interlace is probably a better choice, for film out or "film-look" then progressive would be a more suitable choice.

Phil Balsdon
http://www.steadi-onfilms.com.au

Thank you so much Phil. I know Canon H1 and most other handheld cameras are capable of 24p. Do they still retain 1080 resolution when in 24 progressive? Does the res drop to 720 when in 24p mode? Why these cameras are not favored by filmmakers?
Sorry for so many questions in a single post :-)

Well, first, you're on the JVC Pro HD board, so on this board JVC is favored by film makers. If you go the Canon board, you'll get a different story :) But read the Canon specs those cameras are not outputting 24p, they're outputting 24f (fields), regardless of the res. As Phil noted earlier, 24f is interlaced, but there are plenty of film makers using the H1, so there's no magic camera, it's a matter of preference and money. Good luck! I've heard the Canon H1 puts out a pretty sharp picture, but with the JVC you get the optional native PL mount lens adapter and the flip screen option, which you don't get *from Canon* without going to some of the other vendors. With 5K I can't see not buying an HD110. With 10k, I'm not convinced JVC has the market, it's tough competition in that area between Canon, Panasonic HPX500 for a few thousand more..

Thanks Pete, I mixed up 24f with 24p, now I got it.......

There is no need for inverse telecine since you will be editing a 24p timeline just like film.

PS: some may consider this a "filmmakers" place to hang out, but many of us are aggressively anti-low temporal rate video and believe the BEST thing about the HD200/HD250 is finally having the ability to get adequate progressive temporal resolution. We would say shooting at anything less than 50p is like shooting low-rez DV because it reminds of the "good old days."

Just as max. spatial resolution improves the viewing experience, maximum temporal resolution is equally important. Low temporal rate capture distorts reality and the distortion is very visible and has a name -- judder. IMHO 24p should be treated like switching on "old film" or "sepia" with a consumer camcorder. Use when you want people to think "historic."

Today, viewing high quality images are no longer associated with film -- they are associated with 720p60 video they see on ESPN, FOX, and ABC. When NASA wants to see reality -- they don't shoot film. They shoot 720p60. And, in the next few years they will be shooting 1080p60.

The idea that narrative productions must be shot on film is a belief that is challanged every evening in Japan and Korea where drama is shot and viewed using 1080i60. Good drama is the story, sets, costumes, and lighting -- not 19th and 20th Century frame-rates.

In fact, one could argue that putting people in the "reality" of the situation increases emotional involvement. Why is Aliens far more scary on a huge screen than on an iPod? Why was scope and Cinerama created? Why does IMAX use high frame-rates?

PS: That doesn't mean I don't love old film. But, it's grain that works for me, not the judder because the old directors with their gear driven pans and multi-ton dollies/cranes kept it very much under control. I just don't see the point of using video cameras to try to get a film look.

But, if you do want a film look -- I'm certainly not telling you not to. That's the great thing about the JVC series -- one can choose REAL 24p/25p or REAL 50p/60p.

Very interesting post Steve.
So engrossed in discovering my HD100 I haven't paid too much attention to the 200/250 - didn't realise they shot at 50p (I shoot mainly in 25p) and I haven't as yet seen any 50p footage.
I'm still not entirely sure that interlaced is more 'reality' like than progressive. Interlaced has that in the moment/live studio look but sitting typing this in my room it just seems more natural and I don't think interlaced would entirely convey that?? Hard to judge mind. I know I much prefer the footage I've shot in in 25p over 50i on this camera, I just have to be very careful with the pans (elastic band on a decent tripod helps)...it's frustrating sometimes as I'll need a fast tilt/swing and you can't really get away with that in this format - would 720p50 help out on this or should I really be looking at another camera set up i.e. 1080 interlaced (such as the H1)?

I'm always interested as to what camera's and formats they use on the American shows eg NYPD blue, CSI, Law & Order, 24 - the new series brothers & sisters etc. None of these 'appear' interlaced to me but I've couldn't guess what formats they would use?

Interestingly although it's been said that sport is more suited to progressive it appears that over here at least our main broadcasters are favouring 1080i over 1080p (even though the majority of new tv sets sold now are progressive plasma/LCD panels).

Still as the numerous video's posted on these boards will contest for a camera at this price it can produce some fantastic images.

Steve - I'm going to order your handbook this week - I'm going away for a week soon and will take and 'imbibe' your book then - hopefully the UK have a similar binding service as Kinkos.
Cheers.

You are correct -- it's the 720p50/720p60 that captures most accurately. If you want this look, then the HD200 would be a great upgrade for you.

The BIG network shows are shot on film because they expect to have a very long life in world-wide syndication and the need for maximum possible quality.

Prime time in Japan and Korea simply have a much lower probability of syndication.

However, I'm a faithful viewer of AZN and would love if it went HD.

To be honest - I haven't seen any JVC HD200 50p footage (any on here?). Wondering if it still conveyed a filmic look (though not as 'historic' as 25p).
I'd be pushed to afford another camera at the moment - not sure if i read this correctly but I understood that this camera does not come with a lens which you have to purchase on top?)

AZN as in Asian Televsion? (don't think it quite reaches these stores) Shame as I really like Asian cinema - be interesting to check out their television - I honestly thought they were, along with the US, ahead of Europe in terms of HD broadcast?

Surprised about the shows running on film I just assumed they would now run with high quality HD video (and didn't 24 play with the idea of the JVC HD100 series?).
I don't suppose there is a great deal of difference between 24p and 25p either, in quality terms. The way I read it then is for the look of these big shows (and presumably for certain types of corporate video's) 50p would be ideal. For the specific film look then 25p is a good choice (although I've shot small corporate footage and it fits the purpose very well indeed).
I've seen very sharp, modern interlaced HD camcorders...but the image shouts 'live cooking show/live travel' etc. I'm just not keen on it at all.

Thanks Steve.

The TV show 24 uses the HD100 to shoot some of their backing plates. The show is still shot on Film.

Dan Weber

Steve, I agree completely. I've got an HD100 and it's amazing how many people chew me out for not shooting in 24p. Even after I explain that the per-frame quality of 30p is the same and I am simply getting more temporal resolution, they resist. Even after I explain that none of this footage will ever be transferred to film and, at worst, 24p will be poorly transcoded to a 30/60p digital projection system, they resist. 24p is a buzzword I suppose.

Do you think the hd100->hd200 step is worth it for 60p?

Pete, can I say that when I shoot using Canon H1 or A1 in 24f mode, all I get is field, that means 540 vertical pixels each frame? That is why GY HD is superior for its 720 vertical pixels at 24p?

No that's not how frame mode works. It's not 540 vertical pixels each frame.

You need to get your head around this resolution thing. That's not what makes or breaks an HD camcorder.

Incorrect. The output is indeed 24p. After all, Final Cut Pro and other major NLEs capture it as 24p.

The "f" does not stand for "fields." It stands for "frame." Hope this helps,

There is no "reduction in resolution." You have to understand that 1080i and 720p are equal in bandwidth. Frames from both formats contain the same amount of information.

Phil Balsdon said it best earlier in this thread: "It's difficult to see a difference in resolution with your eye when viewing the two different formats." Hope this helps,

Well, I have to admit that I am confused. Pixels are the most fundamental elements in digital imaging, how can I get my head around pixels? I am from graphics background, sorry if I am asking ignorant questions here about video cameras.

I thought that shooting 24p gives better quality per frame since the camera uses repeat flags rather than 2:3 pulldown. Can someone explain this once and for all?

Videography has an awful lot in common with still photography. In both applications, the number of pixels involved has little to do with actual "image quality" than any number of other, far more important factors. For example, if we compare a compact little digicam having a 1/6th-inch image sensor with ten megapixels on it, and a Digital SLR with a nearly 35mm image sensor with eight megapixels on it, which one will take a "better" picture? The one with more pixels, or the one with a larger sensor, larger and better glass and a better processor? Obviously the one with fewer pixels... lower resolution, if you will... takes a much better picture because other overriding factors (sensor size, quality and size of lens, etc.) make more of an impact upon image quality than do the number of pixels on the chip.

The same holds true for HD camcorders. It's not about resolution.

Again: 720p and 1080i HDV camcorders are recording the *same* amount of information to tape. The choice between 720 progressive vs. 1080 interlace has less to do with the number of pixels than it does with the motion signature and other image aesthetics plus the camera's form factor, ergonomics, price range, application, workflow, feature sets and a number of other considerations. Hope this helps,

It's true that 24p has few frames per second than 30p so yes the math says less compression per frame. But, 30p is half the rate of HDTV at 19Mbps so there is a whole lot of extra bandwidth.

60p, of course, doubles the frame rate and the data that needs to be encoded. But, the GOP length doubles from 6 to 12 which compensates. The encoder is also much better in the HD200HD250.

Bottom-line -- it isn't going to make any difference what frame rate you choose in terms of quality. It's a matter of the look you want. This is a matter of taste.

The other thing to think about is the limitations of 1/3" chips and lens optics at this price point. There seems to be a certain limit as to how much detail can be resolved from the current crop of HDV cameras even if they can do progressive scan video. Take the Panasonic HVX200 for example. This is a true 1080p camera but the chips use pixel shift on 960x540 pixels. While pixel shift is a great way to get extra detail it is not perfect and you will never get a solid 1920x1080 pixels of detail.

What number of pixels a format records is different then what the camera itself can resolve. Think of a flatbed scanner for example. You could scan a 4x6 photo at 300dpi or 1200dpi. While the 1200dpi will have more pixels there isn't really any more detail to the image then the 300dpi version.

So while a 1080p lower cost camera may have more pixels the extra pixels might end up being a little overkill and end up resolving the same amount of detail in the image.

All of this is of course in theory and somewhat true depending on the camera. The newer 1080 cameras that have true 1080p do seem to have a tiny edge in detail over 720p. It is not a lot however and you have to ask yourself if the extra processing for 1080p video is worth that very tiny edge in detail. Now if we were talking a Cinealta camera then maybe there would be a lot of extra detail but any 1/3" camera I have seen is only going to have a tiny edge in detail if any at all. If your focus is not dead on then any edge the 1080 camera had is out the window.

Chris, the following is an excerpt from this article ->http://dvinfo.net/canonxlh1/articles/article06.php. The Canon cameras are indeed interlaced. Correct about the frame/field notation tho.

"The Canon XL H1 CCD block is interlace, not progressive, therefore the 30fps and 24fps frame rates cannot be referred to technically as 30P and 24P. However, 30F and 24F from the XL H1 appear almost indistinguishable from 30P and 24P, as they are basically the same results as progressive scan, but produced by different means. When the XL H1 is set to Frame recording, the CCDs are actually clocked at 24 frames per second. The video signal remains at 24fps as it is passed from the CCD block to the baseband LSI, and through the HD Codec LSI. Only when it reaches the recording output stage is it resampled to 60i via a 3:2 pull-up method."

That's right, the container is 720p60, so 24p has 36 repeated frames while 30p has 30. That doesn't exactly add up to a 20% difference in quality as some may initially believe. I remember seeing some real-world tests a while back and there was no difference in quality between JVC HD100 24p and 30p that couldn't be explained by shutter rate. At the same shutter, the picture was the same. Does anyone know where to find that test, or other tests that disagree?

No need to quote that article to me, Pete -- after all, I'm the one who wrote it!

Since the time that I first put that article together, Canon has released more information detailing how Frame mode works. In the very near future, DV Info Net will host a once-and-for-all in depth explanation of Frame mode, but for now, what's important to understand is what I said in my post above:

Canon's 24F Frame mode does indeed provide 24p output. Period.

Those who doubt this are urged to capture 24F video with the latest version of Final Cut. Guess which capture setting is used -- 1080 HDV 24p! Final Cut cannot distinguish any difference between 24F and 24P. As far as it's concerned, and for all intents and purposes, 24F is 24P.

It doesn't matter that the CCD block is native 1080i. The CCDs are actually clocked at 24 frames per second and what comes out of them is the same results as progressive scan.

There is a slight cost of vertical resolution in this process which is negligible and a complete non-issue for all but the most chronic and habitual of measurebators. Hope this helps,

Ha! That's hilarious. I need to check my sources before I try to pull out the ace card ;)

Ok, thanks for the info. Makes more sense now. I read some articles a few months back on the canon frame mode, less in depth, but still walked away thinking interlaced or interlaced+. What's the reason with Canon not just labeling it as progressive then, if the camera outputs progressive...?

Canon didn't disclose how Frame mode works until November 2006, so anything you read that was written prior to that time has only been speculation. If they had actually called it "progressive," it probably would have caused quite a stir since it is first and foremost a 1080i camera. But in the process I think they created more confusion than they've prevented.

Yes they did. But, your comments are also confusing.

"The CCDs are actually clocked at 24 frames per second and what comes out of them is the same results as progressive scan." Plus, "There is a slight cost of vertical resolution."

If they clock the chips at 24fps and all 1080-lines are output, so output is "the SAME results as progressive scan" then how do they/you explain the "slight cost of vertical resolution." What causes this loss?

The explanation for the loss of V. rez. -- which you agree exists -- is that only 540-lines are output at 24fps. One 540-line field is one field -- and is not a frame. And, this is the reason Canon didn't call it 24p.

No matter how often you deny it -- 24F is type of "field-doubled" video and not true 1080p24. There is no need for measurebating. It's been measured and the numbers published for all to read. And, it's measured resolution shows it to not be 1080p24. It's about 540-TVL/ph on "dynamic" video.

NOTE: "field-doubled" -- contrary the negative reactions by Canon owners is not a negative description. It is a factual description. There are many ways it can be done. Some are crude "line-doubling" while others are very sophisticated and can increase apparent V. rez to more than 540-lines. Canon, obviously does it very well. (However, these processes work best on still images, not moving images. And, video is mostly motion.)

Moreover, the fact Apple named THEIR preset "24p" means nothing about the process by which the video was obtained from the CCDs. It also says nothing about the actual resolution of the video from the Canon.

Sorry to bring this back up Steve - these high quality images used on ESPN, FOX et al and shot on 720p60 - are we talking about news, current affairs etc or drama's? On another post 30p has been referred to as 'live' as opposed to the filmic 24 (and 25 - is there actually a great deal of difference between these two formats...I've heard, somewere, 25p is being used over 24p in the US now?).
I'm guessing then that 720p50 would not merely be the 25p film look but with "adequate progressive temporal resolution" but more akin to interlaced footage....which is where I'm missing something.
You obviously know the hd100 inside out and are a fan, but I personally can't see a reason to choose this camera if it were not for the true 24p/25p true formats?
Has there been any 720p50 footage posted on these boards? I'd be very interested in seeing this.

Our soaps over in the UK are all shot interlaced - they altered one to a film look once (it looked like they had de-interlaced the footage) - it just didn't work at all (probably alienated tons of viewers and they soon changed it back). Same if the news were shot 'film style'.
Blair Witch works very well because of the 'live' camcorder format used (David Lynch's Inland Empire works well in this format also) but then something like the Exorcist, shot on film, really gets under my skin...it had to be shot in film.
There are some terrible judders in films/tv shows shot in film (was watching a bit of ER at breakfast the other morning - if you take your eye of the subjects the background is pretty dizzy).
I presume real film has to be 24p but the likes of Varicam, HDCAM and say a viper (Zodiac being the most recent film I can think of) - will they continue to use a 24p rate of more the likes of 60p?

If I ever need to look for a second camera then I'd just have to retain the film look but also have the flexability to shoot for different visual requirements (HD250 and a 1080i would be probably tick those boxes perhaps).

Forgive me if I've got the wrong end of the stick here, but this intrigues me very much.

There's only one published result I'm aware of that puts Frame mode at 540 lines, and that's the camera test that I helped organized last April. As much faith as I have always put in Adam over the years, I think our limited Frame mode testing was a bit rushed, as we were working hard to get a lot accomplished in a relatively short period of time. If you ask him, I think Adam will readily agree that certain parts of what we did are worth doing over, including the Frame mode tests. After all, if it were only 540 lines then the image would be quite noticeably soft, and nobody I'm aware of who uses the XL H1 on a regular basis has ever claimed it to be. The 24fps output is worth looking at again more closely, in a testing environment that wasn't as ambitious and as rushed as ours. So I wouldn't rely so heavily on 540 lines if I were you.

I am not the one in denial here Steve, and I'm not sure why you're still confused about Frame mode. I know that Canon has tried to help you understand it more than once. 24F is definitely NOT a type of "field-doubled" video. It is not combining fields. It is not doubling fields. It is a full frame capture. And you of all people should know better than to push the term "true" in this business, when you know as well as I do that nothing has been more closely associated with marketing hype than that one word. "True" is a sales pitch which seldom has little bearing on actual real-world results. "True" is a desperate fall-back term that is resorted to when separate technologies compete closely for dollars. But you should know that already.

We're striving for technical accuracy here. Frame mode does not work the way that you seem to think it does. It works instead the way it was explained in detail in New York last November. The publication for which you write, Digital Content Producer, was invited to attend that press conference. You most certainly would not still be clinging to the false notion that it's "field-doubled" had you been there.

Obviously they're not explaining it, but apparently it's the cost of the process, the price that's paid for producing a progressive image from 1080i CCDs. The important thing -- what really matters here -- is that for those who are actually using the camera on a day-to-day basis, it's negligible and entirely inconsequential to the camera's capability to produce viable 24p material that sells. That's what matters most.

Incorrect -- it is not at all a factual description, and I think you're well aware of that. While there is truth to the statement that there are different ways to accomplish field doubling, it's entirely irrelevant to this discussion because there is no "field doubling" in Frame mode.

Actually it means everything, because the entire point here is that if the output wasn't progressive, then it couldn't be captured as progressive. And yet that's just exactly what happens -- not only with Final Cut Pro, but also with Canopus / Grass Valley's Edius and every other major NLE (except Avid, which is sadly behind the curve). Video shot in Frame mode is captured as 24p. There's no separate capture setting. There's no separate capture preset. No distinction at all is made between 24F and 24p. The software can't tell the difference because there is no difference. The output is indeed progressive.

If it wasn't, then you couldn't use a 24p capture setting to get Frame mode video into the editor. But that much should be quite obvious.

As the only multi-camera tests, I must rely on it. And, it seems only Canon and Pana owners -- who don't like the results -- suggest there were problems with both tests. (These are also the only two companies that tried their best to hide their capture process.)

Chris, there are interlace CCDs -- see my books -- that can output ALL lines in one pass as long as the output rate is half their maximum (60Hz) interlace rate. Thus, were Canon to use these CCDs -- they could capture 1080-lines at 30p or 24p.

Why then, is resolution lost? As I remember, these CCDs do Row-Pair summation INSIDE the CCDs. Which is perfect when outputting interlace. But, if it can't be turned OFF for "progressive" mode -- then there will be about a loss of 25% V. Rez.

If I remember, that's about the number you have stated. So, I can think of an explanation that fully matches your description. So, I'm not saying you are wrong!

HOWEVER, I can't explain why Canon tried to hide this and why they were willing to create heat by calling it "F" since, if I'm correct, it is "P." Why would they have done this? Waiting on a patent?

Canon has never contacted me about 24p. In fact, when I wrote my review they refused several times to explain the process to me. Everytime I asked, the USA group got told by Japan they could say nothing!

I have not a single email or document from Canon -- other than their several refusals to explain 24F. Nor did they invite me to their NYC meeting. In fact, searching the DCP website, the only comment I can find is from Dave Leitner's H1 review: "Canon has chosen not to divulge how the camcorder captures 24F and 30F." So, perhaps, Canon never invited ANYONE from DCP! Mike has Dave's email and he has mine. If Canon really cared about getting the facts out -- they've had over a year to do so.


Nooo! All types of HDV is encoded as "Frames." It is recorded as Frames. It is transferred via FireWire in Frames. It's stored on disk as Frames. The only point at which it becomes interlace or progressive is AFTER it is decoded. A flag tells the decoder's output what they frames are.

The way the sensors work before encoding has nothing to do with MPEG-2 encoding, recording, NLE capture, disk storage, NLE decoding.

1080i60 or 1080i50 = 540-lines of vertical information every 1/60th second.

720p60 or 720p50 = 1080-lines of vertical information every 1/60th second.

There have been a few people on this forum that have done tests and show 24F to only have a 10% loss of resolution. The loss could just be due to the fact that interlaced video has a forced 1080 resolution since every other line comes from a different moment in time. Regardless how soft the image is there are 1080 unique lines and sometimes depending on what is being shot it can give the illusion of more detail. 24p on the other hand is meant to be smooth across the lines to make a clear picture so there are smoother transitions between each line.

For example take a shot of a rock. On interlaced each field may be soft but line 1,2,3,4,5 each have a clear edge. On progressive the lines kind of blend together to form a smooth edge of the rock and are not forced to have unique details every other line.


The HVX200 is clearly known as a progressive camera even though the vertical pixels equal 540. 540 progressive pixels pixel shifted and 540 pixels doing whatever F mode does is not going to be all that different. In fact I have always said that 24F was more like pixel shifting the 540 lines so you get a lot more then just frame doubled. Cameras such as the SONY Z1 with Cineframe frame double their footage and 24F has a ton more detail then Cineframe does.

Pros who have shot 24F next to a Cinealta F900 and said they were very close are not fools and know what they are talking about.

I'm sorry but I will take the word of a Cinematographer over a engineer anyday. After all we are shooting video and not building cameras.

Thanks for your input on this Steve. I really appreciate it. And also to Chris for his viewpoint on this. All of this is very helpful to me as I attempt to sort through this very "murky" area and come to a clear understanding of all this. And it's important, because with the wonderful array of new sub-$10k HD cameras (whether HDV or DVCPRO HD or whatever) which are constantly being released, I now find myself asking, "What is REALLY going on?" whenever such a new camera is claimed to have "1080p" capabilities (or even "720p"). And this can affect my future purchases.

Originally, it seemed easy.

You had the Sony F900 which had 1080 horizontal rows (or lines) of pixels (I've never used one, but I've always believed it to have 1080 lines.) The image is captured during the one instant in time and is therefore called "progressive" (as opposed, of course to interlaced, which captures the image in two separate instances in time). It was called 1080p.

Then you had the Panasonic Varicam which has 720 horizontal lines of pixels all captured at the same instant in time. It was called 720p.

When I bought my JVC GY-HD101E two years ago it had 720 horizontal lines of pixels all captured in the same instant in time and was also called 720p.

At that stage, my precision definition for 1080p was "1080 horizontal lines of pixels all captured in the same instant of time".

No longer.

My first departure from this definition was with the announcement on a Panasonic webpage (prior to the camera's release) that the HVX200 recorded "1080p". I became very curious as to how this could be so when I later found out that the HVX200 sensor only had 540 horizontal lines of pixels. This has since been expanded on (thanks to very helpful posts by Jan Crittenden and Barry Green over in the HVX forum) that a 1080i signal is scanned with 1080p imbedded within it and that the 1080p signal can be extracted.

And with the discussion earlier in this thread about the Canon and 1080p, it helped me realize just how much the definition had changed. (Or perhaps it hasn't changed and I've just had an incorrect definition all along.) And thanks to the excellent debate between Steve and Chris I have come to a new realization about this definition.

The definition of "Progressive Scan" has shifted its emphasis away from "Progressive" (WHAT is being captured, how many lines on the sensor) and more towards "Scan" (HOW it is being captured [scanned] and processed afterwards).

Perhaps it is just a natural evolution. Originally you had 1080 lines of pixels that were scanned and processed and delivered to the NLE in a final form of 1080 horizontal lines. So it didn't really matter. WHAT was captured was exactly the same as HOW it was captured and processed and delivered in a final form (in terms of horizontal lines). But once a variation was introduced - smaller sensors than 1080 lines or 720 lines which were coupled with an effort to make a final product delivered to the NLE of 1080 or 720 lines - the emphasis of the definition had to fall on one side or the other.

Perhaps there should be two terms introduced to delineate between the WHAT and the HOW.

There are many, many other criteria for selecting a camera as far as I am concerned (lenses, form factor, image manipulation and control through the menu structure, compression, storage, how the image "looks", sound input connections, etc., etc.).

But I still think it helps to seek more precision with these definitions.

And I reserve the right to totally change my opinion on this tomorrow if more information comes to light!

*** Interlace Scan Dual-line CCDs in Progressive Mode ***

Interlace Scan Dual-line CCDs can be operated in progressive mode—as long as the full frame read-out occurs at no more than half the field rate. In this case, a 1080 camera CCD block can output 50Hz or 60Hz using interlace scanning as well as 25Hz or 30Hz using progressive scanning. You will note that 24fps rate is lower than either of the latter values. So, if a 1080i camera uses Interlace Scan Dual-line CCDs, it can also be switched to capture progressive video at 24fps/25fps/30fps.

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The Canon reads-out 540-lines at 50fps/60fps AFTER it has been passed through a low-pass Row-Pair Summation filter IN each CCD, so output resolution is about 400-lines per FIELD. With a Kell factor of 0.87, the field resolution is about 350 TVL-ph. Total frame resolution is thus about 700 YVL-ph. Measured vertical resolution for the Canon is, in fact, 700 TVL-ph.

Assuming the Canon reads-out 1080-lines at 30fps or 24fps AFTER it has been passed through a low-pass Row-Pair Summation filter IN each CCD, output resolution is about 810-lines per frame.

With a Kell factor of 0.95, the frame resolution would be about 770 TVL-ph. This number is greater than the Canon's Interlace number and, therefore, cannot be the way the Canon works!

That leaves two options: Field-doubling and ADAPTIVE deinterlacing. Chris claims field-doubling is NOT used. By that he means that all 1080-lines from the CCDs are used -- not 540-lines.

Were an adaptive deinterlacer used on the 810-line Frame output by the CCDs -- assuming the deinterlacer preserves on average about 80% of the Frame's resolution -- the Canon's Vertical resolution will be about 564 TVL-ph. (And, 80% is just about right.)

Now, if you compare H1's interlace V. rez. (700) and it's F-mode V. rez. (564) you'll find the loss of resolution to be about 20% -- which is what's been claimed.

So all is well -- no field-doubling and only a 20% loss in V. rez. between modes.

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Because the deinterlacer is adaptive -- were the resolution test to be performed with the camcorder being move slightly to simulate motion -- then such a test would yield 540 TVL-ph. Those who read the tests know Adam did, in fact, "purturb" the cameras during his resolution tests -- as he does ALL cameras.

He does this -- and I fully agree -- because it realistically checks a camera's ability to capture motion rather than simply score well in a static resolution test.

It penalizes those who use any kind of pixel-shift technology -- and read this carefully -- to increase resolution from sensors that physically have fewer pixels than the recording format.

Thus, it does not penalize the Canon in Interlace mode. And, it doesn't seem to affect Sony's V1 interpolation system. And, of course, it doesn't penalize the JVC 720p camcorders.

It also penalizes those who use any kind of "processing" to get frames without interlace artifacts -- rather than use progressive sampling sensors. Because Canon does use such a "process," Canon cannot call it's video "24p."

You can call this unfair, but I doubt Adam will cease. And, neither will I because it allows my math model to estimate "dynamic measured resolution" from "sensor resolution" with an average error of less than one pixel on eight HD cameras.

Moreover, it does not penalize those who use green-shift to "super sample" an image. It simply ignores the super-sampling which is fine because by definition -- "super" means more pixels than needed for the format.

While I agree with you that I prefer 720p at 60fps for many subjects.. however... all of my money earning gigs are distributed on DVD's for the final production, not broadcast 720p at 60fps. So set top DVD players viewed on a Plasma or LCD or DLP simply can't play well a 30p or 60p, only 60i or 24p in a 60i transmission. (If everyone had a Blu-Ray player this wouldn't even be a factor) So I shoot everything in 24p. I have the JVC HD110 so I don't even have the option for the 720p 60fps. How does the 60fps turn out in your 60i DVD's? Maybe I'll break down and get Premier for my mac, that is if Premier even handles the SD 480p 60fps??? could be another real option.

Yes 50, 60p helps a lot, but you are a bit mistaken, Slow and fast pans work well, it's the mid range of pan speeds that we've become used to that produce judder at slower rates. I like 50p, 60p and simply adjust my shooting methods for 25p and avoid the judder. Use prime lenses with the JVC adaptor and inverted image (200/ 250 series) and you can throw the background, which cuts the judder. If the DOF is shallow and you follow your subject then judder/ stutter all but go, adjust your pan rate and it has gone.

So, I'd like to pose some thoughts/questions about this thread, and try to tie it back to the original question.

1) Are cameras that shoot 24p better for film transfers? I mean specifically in terms of cameras within a prosumer price range, which I think was part of the original intent of the post. The discussion here seems to have diverged from that point and was broken apart into separate discussion about a) 1080i vs. 720p and b) the idea that people who ask videographers for 24p just read it in a magazine and have no idea what they're actually asking for.

2) The discussion of "film look" seems to be defined a little bit differently in this thread than I have seen in other places on dvinfo. Specifically I'm seeing references to the stutter caused by a quick moving (panning) camera, whereas other places discuss things like image softness and DoF. I just don't think that anyone clamoring for a "film look" is clamoring for stuttering.

You're all more experienced than I am, so please set me straight on these questions/comments.

The transfer process of video to film requires the image be converted to progressive scan. This is not a perfect or simple procedure for interlaced footage, therefore video images shot originally as true progressive have an advantage and are preferred for the filmout process.

Phil Balsdon
Sydney, Australia

The whole issue of "film-look" and video-to-film is complicated and not a yes and no issue.

24p is ideal for a video-to-film transfer for obvious reasons as there is a one to one transfer without interpolation issues from differing film rates. However 24p shot as video can make film look like video in certain situations.

Film has a long history with all the technical and artistic achievements that comes with a long history. The nature of chemical image recording creates a different image than electronic image recording. Almost all of our great recorded visual entertainment is on film, that's what people are used to. Video is playing catch up with film and everyone wants video to look as close to film as possible for a "quality" look.

Stutter has always been a problem in shooting 24 frames and most cinematographers have developed techniques to avoid it. 60i does not have a stutter problem and most videographers need to learn how to adjust their camera movements to compensate when they start shooting 24p and even 30p.

Film has a softness, partly from the grain which is chaotic and changes from frame to frame, that lends a fantasy element to the image. Video records with a regular pattern that image has to fit into. Also the nature of electronic image pick-up has historically been poor with high contrast images creating unnatural edges on images. This has been improving steadily over the years.

Shallow DOF is something associated with a film-look. It is more of a purposeful decision by scores of film makers over the years. You can have film just as sharp as video and guess what? It starts to look like video. You have have shallow DOF in video and people feel like they are watching film (especially if you are shooting 30p).

The fact is that you have to make a decision based on the production, it's present needs and it's future needs. I just completed a concert DVD. It was shot in HD in 30p for a film-like look that the producer wanted. Why not 24p? This production is never going to film, ever and I didn't want my cameramen worrying about stutter and I didn't want to think about 24 to 60i issues. 30p fits into 60i perfectly. And if the unlikely decision to project it is ever made, it'll look great on Blu-Ray in 30p and the audience will be happy.

The original question was if 720p has enough resolution. For broadcast, DVD and Blu-Ray, yes. For a film transfer, yes but it looks more like Super 16mm then 35. 1080p is sharper but the sharpness does not always translate into a more film-like image.