Native Resolutions (1 Viewer)

[Brad_H]

Hello-

What are the native resolutions for:

TV (OTA Broadcasts)

VHS

S-VHS

DVD (non-progressive)

Thanks.

Brad

 

[Paul Clarke]

Let me try my hand at this. I'm sure I'll get a correction if in error:

Over the Air broadcasts used to be good for 270-330 lines depending on who was broadcasting and what kind of set. The minimum requirement was half of the NTSC 525 line signal.

VHS topped out at 250 on some models but the avg. was 240.

S-VHS could hit 400 and the top models could approach LD quality of 420-425 or so.

DVD seems to be varied but still within the 480-525 range.

Of course 540 seems to be the standard now.

 

[Allan Jayne]

OTA NTSC broadcasting horizontal resolution is limited to 330 lines because that uses up the bandwidth in the broadcast channel available for the picture. Increasing the resolution would cause the video signal to extend into the space reserved for the audio signal, and on into the next channel.
VHS horizontal resolution of 240 or so lines is the limit that can be recorded on the tape. S-VHS uses a better tape oxide coating and also different frequency bands during the recording process allowing up to 400 or so lines.
DVD horizontal resolution of 540 lines comes from the number of pixels across chosen for the DVD standard, 540 out of the total of 720 pixels across fit inside the largest circle that in turn can fit in a 4:3 screen. This "circle rule" was assumed with all of the resolution figures in this reply and is the long time standard for resolution measurements used by the Electronic Industries Association.
In the above cases, including DVD, less than adequate electronics results in lesser horizontal resolution ultimately seen on the screen.
Video hints:
http://members.aol.com/ajaynejr/video.htm

 

[Bill Lucas]

The resolution of DVD is 720 X 480. The potential for more lines of resolution is there but every DVD sold to date is encoded at 720 X 480. Someday HD DVD may/will change that. Regards.