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-   -   why 1440x1080 (https://www.dvinfo.net/forum/general-hd-720-1080-acquisition/37345-why-1440x1080.html)

Collyn Tabor January 5th, 2005 03:47 PM

why 1440x1080
 
We are looking at using a couple of the FX-1's but are concerned with the 1440x1080. What is the deal here? Do the camera's output to 1920x1080 or do you just have a blank on each side? Also 1440 x 1080 is 4:3, how does sony say that the camera is 16:9? Line doubline? Stretching?


Collyn

John Gaspain January 5th, 2005 03:57 PM

I have been wrong before, but this is my best guess.

I was wondering the same question and concluded that the pixel size is 1.333 to 1 therefore giving it 16x9........the pixels are rectangular not square like you would assume.

Hope this helps.

Barry Green January 5th, 2005 05:03 PM

John is correct; the FX1 uses wide rectangular pixels.

HDV records at 1440 x 1080, but the component output up-rezzes so you get a proper 16x9 image.

Actually, just about all HD recording systems record at less than 1920. HDCAM uses 1440 x 1080, and DVCPRO-HD records at 1280x1080.

Collyn Tabor January 5th, 2005 05:16 PM

The Brochure that I just downloaded from sony's pro site says that the 730 and 750 both have 1920 x 1080 effective picture elements. Typo on the DVCPRO-HD? should be 720 instead of 1080 right?

Collyn

Joel Corral January 5th, 2005 05:29 PM

very easy the 1440x1080 is @ 1.333 pixel aspect ratio.

so 1.333 x 1440 = 1919.52 or 1920x1080.

so indeed it is @ 1920 x 1080 square pixels or 1440 x 1080 1.333 pixel aspect ratio.

:)

Barry Green January 5th, 2005 09:50 PM

The camera images at 1920x1080, but the HDCAM recording system downsamples to 1440x1080 before recording. Maybe HDCAM SR records a full 1920x1080, but if so I think it's about the only tape system that does. All the others downsample.

HDCAM downsamples from 1920 down to 1440, and then on playback it'll interpolate new pixels up to 1920 again. That's a 33% increase.

DVCPRO-HD downsamples from 1920 down to 1280, and on playback it'll interpolate back up to 1920, which is a 50% increase.

Gabriele Sartori January 6th, 2005 12:39 AM

very simple
 
"We are looking at using a couple of the FX-1's but are concerned with the 1440x1080. What is the deal here?"
because it is cheaper. Also, the camera doens't have a native1440x1080 pixels CCD. They use a technique called pixel-shifting that is the biggest marketing bs of all times. It is interpolation or "upscaling" That is the reason why this wonderful camera is head and shoulder above the JVC for everything but the resolution...

Bye

Davi Dortas January 6th, 2005 12:44 AM

Re: why 1440x1080
 
<<<-- Originally posted by Collyn Tabor : We are looking at using a couple of the FX-1's but are concerned with the 1440x1080. What is the deal here? Do the camera's output to 1920x1080 or do you just have a blank on each side? Also 1440 x 1080 is 4:3, how does sony say that the camera is 16:9? Line doubline? Stretching?
Collyn -->>>

Well you should look for more. The FX-1 CCD only record 960x1080 real pixels. This then get stretched and shifted around to 1920x1080 on playback.

Dylan Pank January 6th, 2005 06:23 AM

Re: Re: why 1440x1080
 
<<<-- Originally posted by Davi Dortas : Well you should look for more. The FX-1 CCD only record 960x1080 real pixels. This then get stretched and shifted around to 1920x1080 on playback. -->>>

Actually each of the CCDs is 960*1080, but the cam uses pixel shift to create an effective resolution of 1440*1080.

Since MPEG2 uses 4:2:0 colour resolution, there's no significant loss compared to true 1440.

Joonas Kiviharju January 7th, 2005 01:38 AM

Collyn Tabor wrote: "Typo on the DVCPRO-HD? should be 720 instead of 1080 right?"


No, I believe it's not a typo. If I remember correctly DVCPRO-HD is 1280X1080 in 1080i, and 960X720 in 720p. But it has a colour space of 4:2:2, which is alot better than 4:2:0 of the HDV. (Somebody correct me if I'm wrong.)

Toke Lahti January 7th, 2005 03:38 AM

<<<-- Originally posted by Barry Green: Maybe HDCAM SR records a full 1920x1080, but if so I think it's about the only tape system that does. -->>>
How about D5-HD and D6"voodoo".
And D9(=DVHS?)?

Chris Hurd January 7th, 2005 04:00 AM

<< They use a technique called pixel-shifting that is the biggest marketing bs of all times. >>

Absolutely false. Pixel shift technology has been around for years and years and years, it was first introduced by Panasonic and used in some of their higher-end professional video cameras. It most definitely is NOT "marketing bs," it is very real and it works very well.

There is a lot of "marketing bs" in this business, but pixel shift technology is quite the opposite of that. Instead it is a definite benefit. The proof is readily apparent in the image.

Dylan Pank January 7th, 2005 06:09 AM

<<<-- Originally posted by Joonas Kiviharju : Collyn Tabor wrote: "Typo on the DVCPRO-HD? should be 720 instead of 1080 right?"


No, I believe it's not a typo. If I remember correctly DVCPRO-HD is 1280X1080 in 1080i, and 960X720 in 720p. But it has a colour space of 4:2:2, which is alot better than 4:2:0 of the HDV. (Somebody correct me if I'm wrong.)
-->>>

At present there are no DVCproHD cameras that support 1080i, the cameras are all 720p, but can record at 50/60fps, so the 1080i format is used where the producers would rather edit interlaced.

<<<-- Originally posted by Toke Lahti : And D9(=DVHS?)? -->>>

DVHS uses, AKAIK pretty ,much the same specs as DVB HD and is similar to HDV (ie 1440*1080i or 1280*720p, MPEG2 up to 28Mbs) but with additional audio options (AC3 and DTS multi channel surround sound options, and audio datarates of up to 1.5Mbs on the latter)

Graham Hickling January 7th, 2005 10:05 AM

Dylan, If one had an HDV camera and a DVHS deck, is there any straightforward way to add AC3 audio to the HDV footage (during editing) and then get it back onto tape via the deck?

i.e., it would be simple enough to mux the video and AC3 streams....... but would the deck accept it as input?

Gabriele Sartori January 7th, 2005 10:40 AM

Pixel Shifting
 
"Absolutely false. Pixel shift technology has been around for years and years and years, it was first introduced by Panasonic and used in some of their higher-end professional video cameras. It most definitely is NOT "marketing bs," it is very real and it works very well."
Since I'm the marketing VP of an high-tech company I'm glad someone still believe with such a passion in marketing messages. I'm perfectly aware that P.S. has been around for ever, the Canon Gl1, Xl1 etc had it as well. Now, since you know everything, explain to the public how is working (I know, the green channel used for the luminance, I know) and why is mathematically different from a good interpolation. There is nothing mechanical shifting anything in these cameras, it is better you know that...... It is just interpolation! Or do you believe they invent pixles out of nothing?


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