I'm just about to go to Africa to shoot a documentary on a chemist that's spearheading a manufacturing facility to make generic drugs that would help fight AIDS. Most of my shots will be stationary interviews but I'm sure there'll be plenty of shots with the merlin steadicam too. I will be bringing 3 HV20's and using my SD722 for sound.

I've used both formats. I like cineform's 24P look (especially with the Letus I plan on bringing) but I like the 60i form factor more. 24p does better in low light yet not so good with movement. At least in my hands.

My audience is a bit of a three ring circus. I'm hoping to submit the film to some festivals, show it on the local public access channel (yeah, I know) and also provide the kilimanjaro school of pharmacy some footage for their website. I know it's a matter of personal preferance and there's no right or wrong per se but I was curious what others would do in my situation. All thoughts, suggestions, questions, appreciated.

My position is: if you're going to do TV, do interlaced, at least over 24P. I shoot 60P at 1280 x 720 but that's a bit different.

Also, 24P is still an effect when talking about TV. Audience is the web or festivals? Have at 'er!

[QUOTE=Shaun Roemich;964265]My position is: if you're going to do TV, do interlaced, at least over 24P. I shoot 60P at 1280 x 720 but that's a bit different.

I would rephrase it like this:
If the intended end-user equipment can benefit from interlaced material, shoot interlaced.
Otherwise, shoot progressive.

And, in Europe it seems that > 95% of all new household TV sets (CRT:s are a quickly dying breed here) are "flatscreens" (LCD/Plasma).
And these flatscreens have to do de-interlace on all incoming material before displaying it.
Agreed, they de-interlace quite well, but nothing is gained quality-wise compared to true progressive...

/Johan S

Shooting progressive at 60P would be great but shooting at 24p or 30P means that fast motion is forever lost. At least a lot of modern flat panel displays do a good job of deinterlacing and retain most of that motion especially the higher refresh rates like 120HZ here in North America. For a documentary I would shoot interlace that way you would cover most of the possible viewing options and occasional fast camera movements won't make your audience sick from judder!!!

Ron Evans

I have a similar gig but a different country. I seem to recall that 24p locks you into needing a Canon HDV playback capability and is not as future proof as 60i. Not sure about 60p.

I think the other thing that people seem to be getting confused about is thinking that 60i is 30fps . I have recently read several article where the writer states that NTSC is 30fps with each frame split into an odd and an even field. Implying that the camera shoots at 30fps and each frame is split for recording or transmission. The real fact is that the cameras shoot at 60fps and the recording/transmission only records/sends half the vertical information in each of the 60 fields. So the motion recorded is at 60 fps giving the smooth motion the 60i on a CRT gives. Our eyes/brain and the CRT phosphors fill in the missing lines from the fields. For lots of flat panel displays this fluid motion is destroyed by the deinterlacer simplistically changing this interlace frame rate to 30fps progressive displayed twice to get the necessary 60hz refresh rate leading to backround judder etc. I would still shoot interlace and then manipulate in post for the intended audience. Shoot 16x9 HDV 1080i can always be cropped to 4x3 if you are aware of that when you shoot.

Ron Evans

60i is 30 Frames per second.

The difference is in the difference between interlace and progressive footage. With Interlace footage, say 1080i, 30fps refers to 30 Frames per second or 60 Fields per second. You can not have 1080i 60 FRAMES per second. It is 60 fields per second

With progressive footage the number 30fps represents only frames, because their are no fields in progressive scanning. So with 720p60 refers to 60 frames per second. The same with 1080p60.

Except, when you have Progressive Segmented Frames (PsF). In this mode you don't have 60 frames per second.

The frame rate you can have in PsF is :
23.98
24
25
29.97
30 frames per second

60i is 30 Frames per second.

The difference is in the difference between interlace and progressive footage. With Interlace footage, say 1080i, 30fps refers to 30 Frames per second or 60 Fields per second. You can not have 1080i 60 FRAMES per second. It is 60 fields per second

With progressive footage the number 30fps represents only frames, because their are no fields in progressive scanning. So with 720p60 refers to 60 frames per second. The same with 1080p60.


60i is 60 fields per second. Calling it 30 frames per second is incorrect.

30 frames per second = 30 PROGRESSIVE frames per second.

1080P60? If I could shoot that, I would. Right now we're "stuck" with 1080P30.

I think what Ron was describing is even though you are shooting 60i the two fields are placed into one frame BUT each of those fields are 1/60th a second apart in time. This renders motion very well and even on flat panel displays the electronics do a great job of deinterlacing the video.

With my V1U it can capture 30p but it still encodes it into a 60i stream. In this case both fields are from the same timeslice and not 1/60th a second apart as they would be in a true 60i capture. Judder isn't bad but it is there. You have to watch your panning speed with 30p. Either do a slow to moderate pan or a very fast one. You'll have to do some experiments and judge for yourself. Also if you are shooting with a long lens with some camera shake 30p can start to look awful. Especially if you have to crank up the shutter speed some.

60i will render motion more pleasingly than 30p. I only shoot 30p when its going to be a web distribution or if that extra stop of sensitivity I gain makes a difference.

I would recommend 60i for the documentary and avoid 24p if at all possible. You can try 30p and see if you like the look.

Thank you Chris that is exactly what I wanted to say. The cameras are taking pictures at a rate of 60 a second but only recording half the information!!! So has twice the motion information of 30fps.
I too have an old retired VX3, a retired TRV740, retired TRV50 retired PC10 and now use FX1( now getting old too as I got it when they first came out), SR11 and occasionally my HC96.

Ron Evans

60i is 60 fields per second. Calling it 30 frames per second is incorrect.

30 frames per second = 30 PROGRESSIVE frames per second.

1080P60? If I could shoot that, I would. Right now we're "stuck" with 1080P30.
It's no more incorrect than calling NTSC video 30 frames per second. 59.94 fields per second is the same thing as 29.97 frames per second interlaced.


-A

It's no more incorrect than calling NTSC video 30 frames per second. 59.94 fields per second is the same thing as 29.97 frames per second interlaced.


-A

This is exactly the confusion I was addressing in my post. I understand that 29.97 interlace is just a name convention. It does not imply that the camera is shooting at 29.97 frames a second( 30fps drop frame) and interlaced into a 60i transport stream. The camera in fact is shooting at 60 frames a second but only recording fields each time( half the vertical information). You cannot just add these fields together to make a frame and get 29.97 fps progressive. I understand the confusion. Two fields make a frame, so 60i divided by two and using drop frame timecode would be 29.97. The only problem is the odd and even fields are not from the same frame!!!! The fields are displaced by 1/60 of a second each time. They are fields extracted from a 60P image capture in camera processing, especially from some of the newer cameras ( like the Panasonic HMc150) that have the option of multiple output formats. I just feel that 29.97i is an unfortunate convention.

Ron Evans

even on flat panel displays the electronics do a great job of deinterlacing the video.

I'll happily disagree with that with the notable exception of newer consumer displays. Point of sale displays, LCD projectors, computer LCD screens and other such displays do a TERRIBLE job of displaying interlaced footage.

60i is 60 fields per second. Calling it 30 frames per second is incorrect.

30 frames per second = 30 PROGRESSIVE frames per second.

1080P60? If I could shoot that, I would. Right now we're "stuck" with 1080P30.

I don't believe so Shaun.

"The field rate of 1080i is typically 60Hz for NTSC countries (such as United States, Canada and Japan) or 50Hz for PAL/SECAM countries (such as in Europe, Australia, much of Asia, Africa). Because of this the two most common frame rates are 30 frames per second or 25 frames per second. Both variants can be transmitted by both major digital television formats, ATSC and DVB. The frame rate can be either implied by the context or specified after the letter i, such as "1080i30". The European Broadcasting Union (EBU), prefers to use the resolution and frame rate separated by a slash, as in 1080i/30 and 1080i/25, likewise 480i/30 and 576i/25."

I'll happily disagree with that with the notable exception of newer consumer displays. Point of sale displays, LCD projectors, computer LCD screens and other such displays do a TERRIBLE job of displaying interlaced footage.

Computer screens and computer projectors were never designed for video. They don't even work in the same colorspace as video.

I was actually referring to flat panel television sets. They do a great job displaying either interlaced or progressive sources.

Sorry for the confusion.

I don't believe so Shaun.

"The field rate of 1080i is typically 60Hz for NTSC countries (such as United States, Canada and Japan) or 50Hz for PAL/SECAM countries (such as in Europe, Australia, much of Asia, Africa). Because of this the two most common frame rates are 30 frames per second or 25 frames per second. Both variants can be transmitted by both major digital television formats, ATSC and DVB. The frame rate can be either implied by the context or specified after the letter i, such as "1080i30". The European Broadcasting Union (EBU), prefers to use the resolution and frame rate separated by a slash, as in 1080i/30 and 1080i/25, likewise 480i/30 and 576i/25."

See what I mean about confusion!!!! As I said in my earlier post field rate of 60 is the rate at which the camera operates ie 60 frames a second but it only transmits half the vertical resolution in a field. You can't add two consecutive fields and get a frame, they are 1/60sec( or 1/50 in Europe/PAL countries) apart!!!! One can CALL this a frame by convention but to assume this is a technical fact is incorrect. An interlace stream is missing half the information and without the other designed end of the chain( the CRT phosphors and our eyes and brain) the process doesn't work the way it was intended. IT was designed to have the motion characteristics of a higher frame rate than film ( ie 60fps) but only use half the bandwidth. One might call it an analogue compression decompression scheme. Deinterlacers that assume these interlaced fields are from the same frame to produce, 30P or 25P, output terrible results with juddering motion as expected. The only way to get close to the image produced by a CRT is to delinterlace to the equivalent of 60P or 50P for display on a modern flat panel display. Hence the move to 120hz LCD and the sub field drives of the Plasma displays. A side benefit is these refresh rates are nice whole numbers of 24fps for correct reproduction of film transfers as well.

Ron Evans

Thanks for the clarification Chris. There are SO many half truths about displays and video in general out there I try to nip the ones that are not entirely accurate in the bud. WAY too many of my clients have required "deprogramming" over the years because of something they read on the internet...

As I said in my earlier post field rate of 60 is the rate at which the camera operates ie 60 frames a second but it only transmits half the vertical resolution in a field.

Again, not accurate. The camera (assuming interlacing) images the half resolution 60 times per second (for NTSC) AND THEN grabs the alternating lines on the next pass. Your statement about not having a temporally complete frame is accurate but any discussion of NTSC video being 60 FRAMES per second is wrong. PERIOD. 60 fields/30 frames. I'm sorry to be difficult on this but any misrepresentation of fields and frames is wrong.

Again, not accurate. The camera (assuming interlacing) images the half resolution 60 times per second (for NTSC) AND THEN grabs the alternating lines on the next pass. Your statement about not having a temporally complete frame is accurate but any discussion of NTSC video being 60 FRAMES per second is wrong. PERIOD. 60 fields/30 frames. I'm sorry to be difficult on this but any misrepresentation of fields and frames is wrong.

I have a full understanding of fields and frames. I did not say NTSC is 60 frames a second. NTSC is 60i. The missing fields are permanent. You can't add consecutive fields and get 30 full frames. I said the camera is taking pictures at a rate 60 frames a second ( which it is, whether that is half the resolution,a field or full like some of the latest cameras and then decide what they will output the Panasonic HMC150 for example if I am to believe the information) Each camera operates differently. How the camera images the scene is irrelevant only that it transmits a field every 1/60 a second. Frame rates to me mean full progressive frames just like a film camera would take. NTSC 60i is NOT 30P. By convention it is 30 frames( two fields = a frame) which bears no resemblance to the temporal motion of 30 frames a second it just happens to be numeric,60 fields divided by 2 = 30frames. The temporal motion is that of a 60 frames per second capture not a 30 frames per second capture. Hence the terrible confusion and technology problems of deinterlacing for flat panel displays. We are getting hung up on whether a frame is FULL or partial. To me if the camera shutter opens 60 times a second and the camera records this, it is operating at 60 frames a second. What it records is something else, it could be a field or a full frame and what it transmits/records to tape or memory could be something else entirely.
I too am sorry for continuing this topic but there is a big difference between 60i(30frames) and 30P. IF the NTSC 30frames isn't 30P what is it? IT isn't 30i because that would be 15frames..........I will accept the convention. 60i is 30frames as a name only because 2 fields is 1 frame( even if they didn't come from the same full progressive frame).

Ron Evans