This is topic What's the difference between NTSC and PAL? in forum Film-Yak at Film-Tech Forum ARCHIVE.


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Posted by Melany Lowe (Member # 1084) on 01-01-2002, 11:40 PM:
 
Whats the difference between NTSC format video's and PAL format video's...I have no idea...PLEASE HELP!!!

<Subject title edited by Admin so as to not be a teaser>
 
Posted by Paul Cassidy (Member # 951) on 01-02-2002, 12:00 AM:
 
Basically NTSC is 525 horizontal lines stacked ,interlacing 59.94 feilds per sec. odd & even lines displayed sequentially and PAL Phase Alteration by Line (I've heard it called other things) 625 lines horizontal, 25 frames, 50 feilds displayed & interlaced per sec.


 


Posted by Melany Lowe (Member # 1084) on 01-02-2002, 02:43 AM:
 
thanks a bunch
so is there a better one out of the two or are they just the same??
uhh I am talking about all the line things etc (excuse my arrogance)

 
Posted by Paul Cassidy (Member # 951) on 01-02-2002, 03:12 AM:
 
Yes the PAL is considered better quality, as it is a Newer format and is more stable in it's color Hue ,NTSC is sometimes discribed as "Never Twice The Same Color "

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A KIWI eats,roots & Leaves.


 


Posted by Joe Redifer (Member # 3) on 01-02-2002, 03:21 AM:
 
I've always had the following questioon but just have been too busy being lazy to actually ask it:

NTSC can effectively have 60 independent images per second, each field can contain an image of a different object, thus creating the illusion of 60 "frames" per second, as seen in soap operas, the news and the like.

Can PAL do this as well, creating the illusion of 50 "frames" per second, or are the two fields REQUIRED to make up one image frame?

I suppose I should ask about SECAM as well. How about SECAM? Does anyone care about SECAM?
 


Posted by Phil Hill (Member # 371) on 01-02-2002, 03:54 AM:
 
Sure Paul, PAL is better if you like Flicker! Give me a break!!!

NTSC and PAL are both so advanced in processing now that there is no difference other than the lame flicker rate of PAL. (Especially if you are not looking directly at the image)

Also, if you want to do skip-field 3D, PAL sucks worse than NTSC...headache-ville.

PAL is not "newer". It is based on a particular countries' line frequency of 50 Hz as is NTSC is based on the 60Hz line frequency. They were both originally specified by the AC line frequency so as not to produce sync and "hum" problems in early receivers.

PAL's 625 lines vs. NTSC 525 lines has to do with the amount of time available between vertical sync based on the line frequency. 50 Hz has more time between "fields" thus more lines and also more flicker since the refresh rate is much slower.

It might be true that in the past "one" can see a visual diffence between the active lines of PAL and NTSC, but realistically who the F*** cares? All pics look great on a good-quality receiver.

Both systems now have such great processing that it doesn't matter.

>>> Phil



 


Posted by Phil Connolly (Member # 465) on 01-02-2002, 04:03 AM:
 
Yes, with PAL each field is 1/50th of a second, so you do get 50 independent images a second.

SECAM is very similar to PAL, it has 625 virtical lines, it's an interlaced format running at 25 frames, 50 fields per second. The diference from PAL is the way it encodes the colour information. So yes you get 50 independant images a second with SECAM.


 


Posted by Paul Cassidy (Member # 951) on 01-02-2002, 04:09 AM:
 
It was actually the Power that decided the differece between the 2 camps 50Hz & 60Hz, by using the Mains power frequency as the source devided the camp further by having 25 frames (50Hz) and 30 frames (60Hz)the change to color caused NTSC to adjust to 59.94Hz, Hue color problems surfaced with broadcast of NTSC caused by shifts in the sub carrier phase of the signal,a modified version of NTSC appeared in which the sud carrier phase was reversed on each second line ,this we know as PAL "Phase Alternate Lines" some 60Hz countries adopted this (Brazil) the French (trying to protect local industry) used SECAM (SEquential Color Avec Memoire) or better known as (System Essentially Contrary to American Method)most TV sets sold in NZ are able to show both systems and if you have an older set ,some videos have a feature that will play an NTSC signal to a PAL TV ,for DVD (zone 1) you will need a NTSC capable Set or the picture will be in Black & White but with sound.

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A KIWI eats,roots & Leaves.
 


Posted by Pete Naples (Member # 761) on 01-02-2002, 04:09 AM:
 
From my time in TV production.

N.T.S.C. Never The Same Colour Twice

P.A.L. Pictures Always Lovely

S.E.C.A.M. Systeme Essentially Contrare to the American Method (Did that read 'French'??)

PAL & SECAM are not that different, they use the same number of lines, fields etc. It's the colour burst that is different, however it's not THAT different. A PAL machine will generally play SECAM material in monochrome, 'cos it can't read the colour curst and vice versa. BUT I came across the odd machine that whilst not designed to do so, would merrily play SECAM tapes, so I assume that there are some SECAM machines that will merrily play PAL tapes. (I'm talking u-MaticSP, BetaSP, MII and 'C' format here, all this digital stuff is before my time)
Never dealt with NTSC much, just throw the tape in, patch it through the standards convertor and fiddle around until it looked watchable. Still looked yucky compared to PAL or SECAM originated material.
 


Posted by Paul Cassidy (Member # 951) on 01-02-2002, 04:29 AM:
 
Phil Hill , I really don't have a preference as most of my DVDs are Zone 1 and I have a large collection of NTSC Laser Discs (Karaoke and movies) so I do spend alot of time watching NTSC and only PAL when I have the TV on.Still can't beat 70mm or a good 35mm print. NTSC was introduced in 1953 and PAL in 1967.

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A KIWI eats,roots & Leaves.


 


Posted by Joe Redifer (Member # 3) on 01-02-2002, 04:33 AM:
 
Actually NTSC = Never Twice the Same Color

I can't imagine that NTSC looks great converted to PAL, with the loss of frames and the such. I know that PAL looks horrible converted to NTSC. All of the British television that I see here looks pretty boring anyway (and no, I do NOT like Dr. Who). I'd take NTSC progressive scan over PAL interlaced anyday. I really do not like interlacing. Progressive scan is sooooo much smoother. I'm sure that none of the current standards can hold a candle to HDTV.
 


Posted by Phil Hill (Member # 371) on 01-02-2002, 04:47 AM:
 
Paul: I agree, 35mm is much superior to either NTSC or PAL. I, too have a great collection of (NTSC) DVD's and LD's..and (god forgive me: karaoke). Ummm all Region 1. I have produced and have in my private collection many 70mm and 35mm films as well.

And Joe, I agree, the conversion of NTSC to PAL and Visa Versa SUCKS!

I sincerely hope the powers to be will take the proper steps to do a decent job in the conversion to HDTV!

>>> Phil


 


Posted by Mark Gulbrandsen (Member # 72) on 01-02-2002, 09:43 AM:
 
Pete: Actually its just "Never The Same Color" ya all can drop the extra T off the end as its not NTSCT. Having worked for a number of years in Broadcast TV I can definately attest that it is absolutely true. NO matter how long you spend trying to mmatch up a number of cameras they can Never look The Same. I always thought we should ahve gone with the CBS spinnig colorwheel system. There is is a strange film related aura that is created with a spinning disk!
Mark @ GTS

 
Posted by John Walsh (Member # 168) on 01-02-2002, 10:11 AM:
 
The CBS spinning color wheel system was actually approved by the FCC, but then withdrawn- much to Goldmark's dismay and Sarnoff's joy.

For color quality, it was also compared favorably to Technicolor.
 


Posted by Jerry Chase (Member # 660) on 01-02-2002, 12:13 PM:
 
Obligatory comment that the first color live from the moon was via a color wheel. Fast moving images seperate the colors, giving a sparkle effect.
 
Posted by John Pytlak (Member # 331) on 01-02-2002, 01:36 PM:
 
Some links to information:
http://www.cs.sfu.ca/CC/365/li/material/notes/Chap3/Chap3.4/Chap3.4.html
http://www.ee.washington.edu/conselec/CE/kuhn/ntsc/95x4.htm
http://www.stamweb.com/Article%20video_signal.htm

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


Posted by Evans A Criswell (Member # 381) on 01-02-2002, 01:55 PM:
 
quote:

I can't imagine that NTSC looks great converted to PAL, with the loss of frames and the such. I know that PAL looks horrible converted to NTSC. All of the British television that I see here looks pretty boring anyway (and no, I do NOT like Dr. Who). I'd take NTSC progressive scan over PAL interlaced anyday. I really do not like interlacing. Progressive scan is sooooo much smoother. I'm sure that none of the current standards can hold a candle to HDTV.


About progressive being better than interlaced: Yes, progressive scan will look better if the material originated on film where each field pair originated from the same image or the 3:2 pulldown pattern can be detected so that fields can be weaved together producing a result practically identical to what you'd get if a progressive scan system had been used in the first place.

However, if the material was shot for television using a video camera, and the subjects are moving, then there will be movement between every field. Weaving those together to make a progressive image will cause a "square sawtooth" edge on all horizontally-moving objects, since there will be a 1/60 second temporal difference between adjacent scan lines of the progressive image that is created. To do away with this artifact requires some smoothing or averaging of each pair of scan lines which does away with that ugly artifact at the expense of destroying up to half of the vertical resolution of the image. For such material, it's best to just leave it alone and leave it interlaced. I've seen HDTVs in Best Buy that, when playing interlaced NTSC material, lost half the vertical resultion to give a smooth progressive picture, which was noticeably inferior to the ordinary interlaced NTSC sets sitting next to it. However, this set looked beautiful when DVDs were played since the 3:2 pattern could be utilized to make full-resolution progressive frames.

------------------
Evans A Criswell
Huntsville-Decatur Movie Theatre Information Site
 


Posted by Brad Miller (Member # 2) on 01-02-2002, 04:53 PM:
 
Melany, please refrain from using "teaser" subject headers. The title of this thread is "what's the difference between....." really doesn't tell us anything about the discussion and forces people to look at it to see if it is something that interests them.

This practice is specifically discouraged and is covered in the "faq". Thanks.
 


Posted by Melany Lowe (Member # 1084) on 01-03-2002, 04:18 PM:
 
Sorry everyone..I did read the FAQ's but I just forgot..won't happen again
 
Posted by Mark Gulbrandsen (Member # 72) on 01-03-2002, 04:43 PM:
 
John Walsh said in a previous thread......
"The CBS spinning color wheel system was actually approved by the FCC, but then withdrawn much to Goldmark's dismay and Sarnoff's joy."

Yea but when CBS won approval it really pissed the General off and kept him and all of RCA Laboratories at bay for a couple of years till the FCC retracted the approval of the CBS colorwheel. Oddly RCA wasn't really ready to properly demonstrate their system yet when the colorwheel appeared. They had no tri-color crt ready and the demonstration set they used 3 seperate CRT's. In the two years that the CBS system enjoyed some popularity RCA utilized that time to really perfect their system.
MArk @ GTS


 


Posted by Mark Gulbrandsen (Member # 72) on 01-03-2002, 04:53 PM:
 
"The first color pictures from the moon were via a color wheel camera".....

In fact the first Black and white images used a minature version of the image dissector tube for pickup. This is a cold cathode tube(no filament)that has great contrast range although is not very sensitive. It is almost impervious to being damaged(short of being broken).
The original image dissector was invented by Philo T. Farnsworth in about 1926. It was the first operable camera pickup tube ever made that actually could produce a picture. This invention also caused much havock for Sarnoff at RCA as they still had to rely on the spinning disk camera. Later improvements in this tube by ITT made it more compact and higher sensitivity for use on the moon. Not only did it make the camera lighter but it also made it simpler and more reliable. Luckily, before Farnsworths death, he got to see these live TV images beamed back from the moon via a camera that used alot of his original inventions.
MArk @ GTS


 


Posted by Phil Hill (Member # 371) on 01-03-2002, 06:56 PM:
 
Spinning Wheel system.... It did look great...until a fast-moving object was displayed! Then you saw individual RGB images in sequence. This effect can be seen in the early moon-landing/takeoff videos that used the sequencial system.

It's interesting that the "hottest", "latest", "high-tech", (etc), DLP technology uses a single MDM chip and a spinning color wheel to keep costs and size reasonable. Brings back memories of the aluminum xmas tree....

>>> Phil


 


Posted by Josh Jones (Member # 447) on 01-07-2002, 01:06 AM:
 
Could someone please tell me what a temporal softner does? one of my video adjustment programs has this and it does make the image look better, but I cant describe how. for the record the program is called virtual dub. it also has a nice deinterlace feature that cleans up my captured video.

By the way, if you thought color wheels were cool, just wait till you see a nipka(sp?) scanning disk camera and receiver. it was very similar to the Baird scanning system. there was also a prismatic system, but all of these went out the window when we found a vacuum tube that could produce a watchable picture.

Josh


 


Posted by Sean McKinnon (Member # 612) on 01-07-2002, 03:15 AM:
 
Yeah I noticed that too when you think you have you cameras on perfect phase according to the scopes, they still look like crap.
 
Posted by Paul Mayer (Member # 355) on 01-07-2002, 07:38 PM:
 
Not that I'm an NTSC apologist, but blaming non-matching cameras on the encoding system is just plain silly, and more reveals a lack of talent or experience on the the part of the VC or V2 (camera shader) rather than any shortcoming in the encoding system. Present company on this forum excepted of course!

Like the so-called "projectionists" in many neighborhood multiplexes these days, the talent level of VCs (assuming there are any VCs on staff) in local-market broadcast TV, industrial TV, or even network-level sports TV, is generally pretty low. Why? Because these segments of the professional video world are entry-points, places where dues must be paid and experience gained before one can move on to industry segments (such as freelancing on network-level shows) where the production standards (and pay rates!) are much higher. Most of the engineers that work in these aforementioned segments are newbies talent-wise, even the ones that have been there a while (the ol' first year of experience, repeated for 20 years syndrome). These folks' newness is betrayed in the pictures they make.

If cameras don't match after being aligned on a waveform/vector scope, it's because the individual encoders haven't been fully aligned. If the cameras don't match on the chip charts even if their internal bars match on the scopes, it's because the cameras haven't had their grey scale tracking fully checked. If the cameras don't match even after the bars match, and the chip charts match, that's to be expected due to lens flares, which must be "painted" on the fly for high quality production anyway. Painting blacks, watching detail level (the required amount varying with lens zoom and iris position), and watching SCH phase is most of what a VC does, along with the basics like iris and black levels, during actual production.

Often in these entry-level industry segments, production budgets don't allow for a separate VC, that duty falling instead to a studio/truck maintenance engineer, who may know the hardware but still not have the eye. Or even worse, VC gets entrusted to automatic circuits (auto-iris, auto white balance, auto black balance). Even if a real VC is budgeted, the production facility itself often lacks a real VC work position (i.e. no contaminating light, with a separate, real match monitor and switcher). As always, one gets what one pays for. Non-aligned cameras will look just as "bad" regardless of the format, be it ATSC, 601, PAL, SECAM, or NTSC in any of their flavors.

Jeez, that sounded like a rant. Wasn't meant to be. Just my 0.02USD. Cheers!

Paul
Mercenary film/video projectionist/engineer
"When the money runs out, so does I."
Member SMPTE Hollywood Section
Back in 'Vegas, still looking for something to do



 


Posted by Sean McKinnon (Member # 612) on 01-08-2002, 02:25 AM:
 
Well my video experience was with a public access station, so the equipment wasnt the greatest to begin with. Hell, most "producers" didnt even white balance before they rolled tape. (or theyed white balance then shut off the lights go out to lunch come back 2 hours later, tape then wonder why it doesnt look right)
 
Posted by Brian Hogan (Member # 940) on 01-14-2002, 03:02 PM:
 
wowsers... all i ever wanted to know and more!
 
Posted by Steven Pickles (Member # 785) on 04-15-2003, 09:31 PM:
 
I'm going to add my two cents into this discussion. First off the human eye "sees" an image flash on the retina -- and that image is kept there for a few milliseconds before "disappearing." Any stream of images greater than 50 images per second the eye cannot distinguish the difference between continuous and discrete image signals. This is due to the reponse time of the visual cortex part of the brain and the retinal response to the images. ALL video and film systems exploit this to trick your brain into thinking you are watching a non-discrete moving picture.

A two-dimensional black and white video signal is encoded with a camera scanning an electron beam moving quickly across an image and slowly down the image, all the while recording the intensity of light. A frame is produced with the intensity as a function of time (known as broadcast). This is transmitted and then received using the same process to reconstruct the image. The way this is done varies from country to country and the number of scanning lines varies accordingly as does the frame ratio.

Color video is encoded the same way as the black and white example above but three beams are used instead of one. The three beams are red, green, and blue... as any color can be reproduced with a superposition of the three with the correct intensity. The three are combined into a composite for transmission.

Luminance and chrominance play an important role in the transmission. As humans, we pick up on luminance much more acutely than chrominance. As a consequence the luminance signal is transmitted more accurately than the chrominance signals. These signals can be adjusted by changing the intensity of the brightness, hue (tint), and saturation (color).

NTSC = National Television Standards Committee
∙ 525 vertical scan lines (of which 483 are displayed)
∙ horizontal to vertical aspect ratio of 4:3
∙ 29.97 frames/second

PAL = Phase Altering Line
∙ 625 vertical scan lines (of which 576 are displayed)
∙ horizontal to vertical aspect ratio of 4:3
∙ 25.00 frames/second

SECAM = SEquential Couleur Avec Memoire
∙ 625 vertical scan lines (of which 576 are displayed)
∙ horizontal to vertical aspect ratio of 4:3
∙ 25.00 frames/second

The smoothness of the motion is determined by the number of DIFFERENT images per second. 25.00 frames/second is technically fast enough not to notice non-fluid motion, but older people can sometimes perceive the image to flicker. Flicker is determined by the number of times the screen is painted per second. For example, a still image painted at 20 frames/second will not show jerky motion but will flicker. If a film is shown at 20 frames per second but at 80 Hz it will not flicker but will appear jerky. To eliminate this problem, a process called interlacing is used. First all the odd scan lines are displayed followed by the even ones. The term progressive is associated with interlacing not being NOT used.

Interlacing is NOT needed on computer monitors.. and so they scan progressively.

** Some of the information above is from "Modern Operating Systems" by Andrew S. Tanenbaum
 
Posted by Steve Kraus (Member # 476) on 04-16-2003, 12:31 AM:
 
Strictly speaking you can separate the color system from the scan rate & number of lines. PAL color isn't really much different than NTSC; just that the color subcarrier phase flips from one line to the next which means that if there is an error causing a color shift adjacent lines will have opposite color shifts and the eye will average them back to the correct color.

Another point of interest is that 625 lines x 25 fps = 15625 while 525 x 29.97 fps = ~15734 which is very nearly the same so the amount of information being sent is similar.
 




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