VHS capture confusion with ADVC-100

srymm wrote on 3/10/2003, 2:18 PM

I am converting some old VHS video tapes to DVD using my new Canopus ADVC-100 with VV4 and am confused about a couple of things.

I start a new project with the DVD NTSC template and capture my video. My first point of confusion is that the capture resolution 720x480 is not 4:3 aspect ration yet it looks fine on the computer screen. Then I use “Print to Tape” to send it back to the TV to see how it looks. I am comparing the same frame with text from both the original VHS tape and the one coming from the computer. The text is in the same place horizontally but vertically, the text from the computer frame is a little above the text in the VHS frame. I can’t figure out why. Ideally I want the computer’s frames to look identical to the original frames from the VHS tape.

Would someone please help me. Thanks…

Scott

Comments

JackHughs wrote on 3/10/2003, 3:27 PM

Hi,

This could be a very interesting question. Did you observe the text actually move in relation to the background or did the entire frame (text and background) shift vertically?

JackHughs

Chienworks wrote on 3/10/2003, 3:39 PM

The frame is 720x480 because the pixels aren't square; they're a little bit narrower than they are tall. In fact, The screen isn't 4:3, it's actually about 4.09091:3. The software takes care of squishing the pixels appropriately to keep the dimensions correct.

I could see the positioning on the screen varying some depending on which source is feeding the television. I've seen VHS tapes have the picture positioned differently on the TV when played in different VCRs. The difference can be rather large when switching from one TV to another. Often a large part of the edge of the frame isn't visible on the television screen due to overscan. If the text isn't exactly centered then it will seem to shift if the overscan percentage changes. As long as you can see the important areas of the picture then i wouldn't worry about these shifts. Just keep anything important away from the edges of the frame. (I'll admit that's not very useful advice for anything you've already shot though.)

srymm wrote on 3/14/2003, 8:31 AM

Thanks for your replies. The entire frame is shifted - both of the text and background. I asked this same question on the Canopus forum but I guess no one knew why either. Thanks for your help.

Scott