q16 x 9 mode on PD-170 is anamorphic at DVinfo.net

David Morgan · March 8th, 2009, 12:12 AM

According to the test I just did, this camera records anamorphic.
The viewfinder shows a letterboxed image. However, I don't see the argument that there is a loss of vertical resolution in this mode. It is not letterboxing the recorded image, it is squeezing it.
Any difference of opinion?

Adam Gold · March 8th, 2009, 01:56 AM

No, this has been gone over many, many times.... like two threads down or the sticky above.

Anamorphic just means anything that isn't in proportion vertically to horizontally.

It is not *squeezing* it horizontally. It is letterboxing it and then *stretching* it vertically, trying to make 360 lines of picture fill 480 (SD) or 1080 (HDTV) lines.

If it was really doing anamorphic like an anamorphic lens would, your horizontal field of vision would increase. But it doesn't. If you shoot a soccer goal where the posts on either side line up exactly with the left and right edges of the frame, adding a real anamorphic lens would add territory beyond those posts. But when you switch WIDE mode on a VX or PD, the posts are still in the same place and no expanded field of view is captured.

http://www.adamwilt.com/DV-FAQ-etc.html#widescreen

David Morgan · March 8th, 2009, 09:30 AM

hum.......alright. A little hasty here :-)

Boyd Ostroff · March 9th, 2009, 08:46 AM

Quote:

Originally Posted by Adam Gold

If it was really doing anamorphic like an anamorphic lens would, your horizontal field of vision would increase.

This statement is not necessarily true. The significant fact is that the VX and PD cameras don't have enough pixels on the ccd's, and not their field of view. There are some cameras with 4:3 high resolution CCD's. They also do 16:9 by letterboxing the image, but there are enough pixels to sample the full resolution 854x480 area. The extra pixels on these cameras are also used in a still photo mode. Sony, Canon and others were making consumer cameras like this before HD became popular.

But in the case of the VX and PD, you don't get full resolution 16:9 because the CCD's only have 480x720 pixels available.

Adam Gold · March 9th, 2009, 12:09 PM

You're absolutely correct in your description of the chips, but they are two different issues. A real anamorphic lens adapter would by definition (no pun intended) add to your horizontal field of view.

As Wilt says in his article above:

"You can tell when a camera is capturing 16:9 the "right way" because when you throw the switch, whether the resultant image is letterboxed in the finder or squashed, a wider angle of view horizontally is shown, whereas the same vertical angle of view is present. "

Boyd Ostroff · March 9th, 2009, 01:30 PM

Quote:

Originally Posted by Adam Gold

A real anamorphic lens adapter would by definition (no pun intended) add to your horizontal field of view.

Well you're talking about an optical adaptor, and you are also assuming that (my hypothetical camera) has ccd's with only 720x480 pixels. Look at Chris' diagram of the XL2 sensor here: Canon XL2 CCD Block Overview by Chris Hurd

The XL2 uses 4:3 native CCD's with 960x720 pixels. Now it turns out that they chose not to use the pixels in the black bands, so when you switch to 16:9 mode the field of view will expand. Given that kind of CCD block, they might just as well have chosen to use the full 960x720 area for 4:3 mode, and if they had, then there would be no field of view change.

Some other cameras did go this way. The Sony PDX-10 had high res 4:3 native sensors but also had a high quality 16:9 mode which was sampled from more than 480 vertical lines. If you switched the camera into still photo mode you would use the entire CCD's and get a 4:3 image. In 16:9 mode you were using a letterboxed portion of the 4:3 chips, and the field of view was the same width as the 4:3 mode.

March 8th, 2009, 12:12 AM	#1
David Morgan Major Player Join Date: Oct 2006 Location: Burbank CA Posts: 466	q16 x 9 mode on PD-170 is anamorphic According to the test I just did, this camera records anamorphic. The viewfinder shows a letterboxed image. However, I don't see the argument that there is a loss of vertical resolution in this mode. It is not letterboxing the recorded image, it is squeezing it. Any difference of opinion?

March 8th, 2009, 01:56 AM	#2
Adam Gold Inner Circle Join Date: Jan 2007 Location: Woodinville, WA USA Posts: 3,467	No, this has been gone over many, many times.... like two threads down or the sticky above. Anamorphic just means anything that isn't in proportion vertically to horizontally. It is not squeezing it horizontally. It is letterboxing it and then stretching it vertically, trying to make 360 lines of picture fill 480 (SD) or 1080 (HDTV) lines. If it was really doing anamorphic like an anamorphic lens would, your horizontal field of vision would increase. But it doesn't. If you shoot a soccer goal where the posts on either side line up exactly with the left and right edges of the frame, adding a real anamorphic lens would add territory beyond those posts. But when you switch WIDE mode on a VX or PD, the posts are still in the same place and no expanded field of view is captured. http://www.adamwilt.com/DV-FAQ-etc.html#widescreen

March 8th, 2009, 09:30 AM	#3
David Morgan Major Player Join Date: Oct 2006 Location: Burbank CA Posts: 466	hum.......alright. A little hasty here :-)

March 9th, 2009, 12:09 PM	#5
Adam Gold Inner Circle Join Date: Jan 2007 Location: Woodinville, WA USA Posts: 3,467	You're absolutely correct in your description of the chips, but they are two different issues. A real anamorphic lens adapter would by definition (no pun intended) add to your horizontal field of view. As Wilt says in his article above: "You can tell when a camera is capturing 16:9 the "right way" because when you throw the switch, whether the resultant image is letterboxed in the finder or squashed, a wider angle of view horizontally is shown, whereas the same vertical angle of view is present. "