View Full Version : curious about 16:9 discussion


Mike Moncrief
February 17th, 2004, 05:26 PM
Hello all,

I was reading another thread on the VX2100/PDP 170 area.. where someone was asking opinions on widescreen 16:9.. and it was mentioned that they should try the PDX 10.. Which is of course good advice.. Someone also alluded to the idea (and this is not the first time i have heard this) that the PDX-10 picture was actually better in 16:9 mode versus 4:3 mode.. Can someone give me a explanation or maybe opinion of why this would be so??

Thanks,
Mike M.

Graeme Nattress
February 17th, 2004, 07:39 PM
I don't think it's better in 16x9 - it looks equally excellent in both 4x3 and 16x9 to my eyes. Although I rarely if ever go into 4x3 as I bought it for the 16x9!

Graeme

James Sullivan
February 17th, 2004, 08:20 PM
16x9 is a beautifull format.

Jan Roovers
February 18th, 2004, 03:20 AM
<<<-- Originally posted by Mike Moncrief : Hello all,

I was reading another thread on the VX2100/PDP 170 area.. where someone was asking opinions on widescreen 16:9.. and it was mentioned that they should try the PDX 10.. Which is of course good advice.. Someone also alluded to the idea (and this is not the first time i have heard this) that the PDX-10 picture was actually better in 16:9 mode versus 4:3 mode.. Can someone give me a explanation or maybe opinion of why this would be so??

Thanks,
Mike M. -->>>

I have a PDX10p and for what I see, Ithink the PDX10(p) is optimally tuned for 16x9. I think this cam cannot be optimalised for both settings.
The vertical resolution is a bit better in 16x9 then with 3x4. The horizontal resolution is difficult to judge and to compare but seems near to be the maximum one can expect from the DV format in 16x9. Overall I like the picture in 16x9 better then 3x4.
The overall impression in 16x9 is very sharp with a high resolution very much towards DV maximum performance.

See EIA1956 16x9 (http://www.jtv.be/JTV/captures/stills/testbeeld-720x576.html)

Tom Hardwick
February 18th, 2004, 12:47 PM
Tests of the camera in the 4:3 and the 16:9 mode show that switching to widescreen noticeably reduces viewfinder vertical resolution as black bars appear to show the new aspect ratio. Graph paper filming tests show that the 16:9 mode uses 10% less vertical CCD pixels than in the 4:3 mode but 20% more horizontal pixels. In a perfect world the vertical resolution would remain unaffected and the horizontal pixel count would increase by 25%, but this Sony solution is most certainly a step in the right direction. Low light sensitivity, Steady Shot and camera control are all unaffected by the switch to widescreen, though the telephoto reach is somewhat reduced and the slight barrel distortion visible at the wide-angle end of the zoom becomes more apparent.

tom.

Ignacio Rodriguez
February 18th, 2004, 01:33 PM
Vertical use of the CCD array does not seem to vary from 4:3 to 16:9 (in video modes) in the NTSC version. Perhaps Sony had to reduce vertical resolution in the PAL version because the DSP or data bus does not have enough bandwidth for all those pixels.

Tommy Haupfear
February 21st, 2004, 12:30 PM
Is this what you guys are talking about vertical loss with the PDX10 in 16:9? That would mean that there is a vertical zoom when going back to tape and that equates to resolution loss (doesn't look like much though).

http://www.maxent.org/video/images/16x9/16.9_compared_sm.png

Ignacio Rodriguez
February 22nd, 2004, 10:22 AM
I don't think there would be a res. loss because the CCD is quite oversampled for video.

Tommy Haupfear
February 22nd, 2004, 10:46 AM
I don't think there would be a res. loss because the CCD is quite oversampled for video.

I'm not so sure the PDX10 is capturing 853x480 with only horizontal anamorphic compression and no vertical zooming.

Anyone else have info on this?

http://img.villagephotos.com/p/2003-5/74415/PDX10.jpg

Julian Luttrell
February 23rd, 2004, 01:08 PM
853?

Where did that number come from?

Julian

Tommy Haupfear
February 23rd, 2004, 02:57 PM
853?

Where did that number come from?

Thats the dimensions of 16:9 footage after being un-squeezed on a 16:9 SD monitor (HD sets may up-rez).

The PDX10 anamorphically squeezes its 16:9 image to 720x480 and then your DVD player displays it as 853x480.

http://www.doom9.org/index.html?/aspectratios.htm

Julian Luttrell
February 23rd, 2004, 03:28 PM
I agree the ratio of the width to the height of a 16:9 image is 853:480. But I don't think you'll ever find 853 pixels being passed around the place - this ratio exists only in the analogue world of transmission.

The PDX10 is capturing 720x480 pixels. These pixels correspond to different areas of the (analogue) CCD depending on which mode you are in. But whether 4:3 or 16:9, there are 720 horizontal pixels, not 853 or any other number.

It's likely that digital widescreen sets with displays larger than 720 pixels across or 480 pixels high may upconvert the digital video to a different frame size at some point in the transmission path. But that's way after the PDX10 has passed its image on!

Regards,

Julian

Tommy Haupfear
February 23rd, 2004, 04:26 PM
Sure the PDX10 writes to tape at 720x480 because of the limitations of the DV format. The anamorphic process is carried out before its written to tape and in the PDX10's case takes advantage of the megapixel CCD. The "video actual" of its 16:9 mode is not published from what I've seen but its more than likely 853x480 or larger.

My Panasonic NV-GS100 (NTSC) captures a 934x576 section of the CCD and then extracts a 720x460 image. Then as its written to tape there is a 1.04x vertical zoom to achieve DV's 720x480. It would be nice to see the same information published for the PDX10.

http://img.villagephotos.com/p/2003-5/74415/PDX10.jpg

Julian Luttrell
February 24th, 2004, 02:50 AM
Ah, I misunderstood your post.

Julian

Boyd Ostroff
February 24th, 2004, 08:00 AM
Have you seen the images and notes at http://www.techshop.net/PDX-10? Using a the PAL version the author compared coverage in still photo mode (1152x864) to the video modes. He theorizes the PDX-10 uses 1152x648 of its CCD pixels for 16:9 and 960x720 for 4:3.

Tommy Haupfear
February 24th, 2004, 08:43 AM
1152x648. That is impressive! So basically the width of the 16:9 mode and the digital stills are the same.

If we could add progressive scan, a few more pixels, and a better recording medium the PDX10 could be a 720p marvel.

Tom Hardwick
February 25th, 2004, 03:17 AM
Yes, the width of the 16:9 mode and the digital stills are the same. But the price you pay for having tiny 1/5" and mega-pixel chips in your camcorder is in low-light performance. It's quite a price; the VX2k is 3 stops more sensitive but the stills to memory and the 16:9 mode (in controlled, non CCD smear lighting) are impressively better on the PDX10p

tom.