Aspect ratio question at DVinfo.net

Go Back   DV Info Net > Canon EOS / MXF / AVCHD / HDV / DV Camera Systems > Canon HDV and DV Camera Systems > Canon XH Series HDV Camcorders

Canon XH Series HDV Camcorders
Canon XH G1S / G1 (with SDI), Canon XH A1S / A1 (without SDI).


Reply
 
Thread Tools Search this Thread
Old September 13th, 2007, 07:49 PM   #1
Regular Crew
 
Join Date: Aug 2007
Location: Fremont California
Posts: 27
Aspect ratio question

Another newbie question.

What is the relationship betweem 1.333 and 16:9? What I mean is although I know 16:9 is an SD format, is 1.333 similar? When I am seeing a DVD in letterbox format, has that been converted to 16:9, or is it some other ratio?
Jeff Yin is offline   Reply With Quote
Old September 13th, 2007, 08:57 PM   #2
Major Player
 
Join Date: Jan 2007
Location: Portland, OR
Posts: 949
There is no relationship. 16:9 is an aspect ratio, a common one. 1.333 is a *pixel* aspect ratio used by some formats (e.g. HDV 1080).

An aspect ratio describes the shape of the entire frame. A *pixel* aspect ratio describes the shape of individual pixels.

A widescreen DVD contains an image with 720x480 pixels (3:2 ratio) but they are stretched by a factor of 1.2 (the pixel aspect ratio) during playback to make the frame appear in 16:9 aspect ratio (864x480).
Daniel Browning is offline   Reply With Quote
Old September 14th, 2007, 01:29 AM   #3
Wrangler
 
Join Date: May 2003
Location: Houston, TX
Posts: 4,093
In addition to Daniel's correct comments, 4:3 DV is also 720x480 (NTSC), but with a pixel aspect ratio (PAR) of 0.9. Then 1.2 / 0.9 = 1.33. So the 1.33 is the difference in PAR between 4:3 and 16:9 and also the difference in image aspect ratio since they contain the same number of pixels. If you make the shape of the pixels of either one of them square instead of "stretched" or "squashed," the pictures will have, just as Daniel said, a picture W:H ratio of 3:2.

Just for clarification, the 864x480 is what a 16:9 image would be if you resampled it to square pixels, rather than 1.2 PAR, which some software programs and add-in cards do.
__________________
Pete Bauer
The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. Albert Einstein
Trying to solve a DV mystery? You may find the answer behind the SEARCH function ... or be able to join a discussion already in progress!
Pete Bauer is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Canon EOS / MXF / AVCHD / HDV / DV Camera Systems > Canon HDV and DV Camera Systems > Canon XH Series HDV Camcorders

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 10:16 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network