16:9 vs. 4:3 Resolution/Cropping

Guy Bruner · January 2nd, 2004, 04:57 PM

Thanks Rob. I did some more reading and think I understand DV Widescreen a little better. The way I understand it is that 4:3 and 16:9 DV is 720x480. In 4:3 DV each pixel is .9091 times as wide as it is tall. In 16:9 DV, each pixel is 1.2121 times as wide as it is tall. So, to make the aspect look correct when displaying 16:9 (e.g., back to a .9 pixel ratio on screen), the camera has to stretch the 4:3 image vertically by 1.3 when it records the 720x480 image to tape.

I guess that Vegas takes that 720 pixels per line and multiplies it by 1.2121 and lists that (872 or 873 with rounding) as the effective number of square pixels per line even though there are only 720 actual pixels.

Rob Lohman · January 4th, 2004, 02:06 PM

That is completely correct Guy! Good job!

Guy Bruner · January 6th, 2004, 08:29 PM

Well, all the math aside. Pictures are mightier than words...or some such quote...I have posted a couple of videos on my website that show how well the DV953 macro focuses and its quality in 16:9 frame mode. They are slow motion videos of a liquid drop in MPEG2 (Main Concept) and WMP 9 HD. The DV953 is only about 3 inches from the liquid...incredible! Video rendered in Vegas 4.0.

Frank Granovski · January 7th, 2004, 02:14 AM

Thanks, Guy! 3 inches away?

Guy Bruner · January 7th, 2004, 03:53 AM

:-) That's my estimate. The shot was taken with manual focus, no zoom and stuck as close to the liquid as I could get. Resolution is fantastic. Those vertical lines you see on the left, center and far right of the picture are wear marks on the outside of the glass along the fluting.

Ayosha Kononenko · January 7th, 2004, 08:20 AM

Hi Guy,

Just saw wour liquid drop clips. Realy nice. I like the resolution.
And you captured the suspense just right. What was the shutter speed?

Guy Bruner · January 7th, 2004, 09:31 AM

Thanks for the kind words, Ayosha. It was shot at 1/60 shutter in bright kitchen light, no fill. Maybe if I had had more light, I could have stopped down to increase the sharpness a little or raised the shutter speed to reduce blur.

January 4th, 2004, 02:06 PM	#17
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	That is completely correct Guy! Good job! __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

January 7th, 2004, 08:20 AM	#21
Ayosha Kononenko Regular Crew Join Date: Jan 2004 Location: London UK Posts: 51	Hi Guy, Just saw wour liquid drop clips. Realy nice. I like the resolution. And you captured the suspense just right. What was the shutter speed? __________________ ayosha

January 2nd, 2004, 04:57 PM	#16
Guy Bruner Major Player Join Date: Nov 2003 Location: Ashford, AL Posts: 937	Thanks Rob. I did some more reading and think I understand DV Widescreen a little better. The way I understand it is that 4:3 and 16:9 DV is 720x480. In 4:3 DV each pixel is .9091 times as wide as it is tall. In 16:9 DV, each pixel is 1.2121 times as wide as it is tall. So, to make the aspect look correct when displaying 16:9 (e.g., back to a .9 pixel ratio on screen), the camera has to stretch the 4:3 image vertically by 1.3 when it records the 720x480 image to tape. I guess that Vegas takes that 720 pixels per line and multiplies it by 1.2121 and lists that (872 or 873 with rounding) as the effective number of square pixels per line even though there are only 720 actual pixels.

January 6th, 2004, 08:29 PM	#18
Guy Bruner Major Player Join Date: Nov 2003 Location: Ashford, AL Posts: 937	Well, all the math aside. Pictures are mightier than words...or some such quote...I have posted a couple of videos on my website that show how well the DV953 macro focuses and its quality in 16:9 frame mode. They are slow motion videos of a liquid drop in MPEG2 (Main Concept) and WMP 9 HD. The DV953 is only about 3 inches from the liquid...incredible! Video rendered in Vegas 4.0.

January 7th, 2004, 02:14 AM	#19
Frank Granovski Outer Circle Join Date: May 2002 Location: Hope, BC Posts: 7,524	Thanks, Guy! 3 inches away?

January 7th, 2004, 03:53 AM	#20
Guy Bruner Major Player Join Date: Nov 2003 Location: Ashford, AL Posts: 937	:-) That's my estimate. The shot was taken with manual focus, no zoom and stuck as close to the liquid as I could get. Resolution is fantastic. Those vertical lines you see on the left, center and far right of the picture are wear marks on the outside of the glass along the fluting.

January 7th, 2004, 09:31 AM	#22
Guy Bruner Major Player Join Date: Nov 2003 Location: Ashford, AL Posts: 937	Thanks for the kind words, Ayosha. It was shot at 1/60 shutter in bright kitchen light, no fill. Maybe if I had had more light, I could have stopped down to increase the sharpness a little or raised the shutter speed to reduce blur.