"white clip extension" in VHS HQ, what does it mean

infoeater · 19th August 2013, 22:47

While reading article on Wikipedia I found a term "white clip extension". Google find only many copies of Wikipedia article. I found that "extension of the white clip level (...) sharpens the picture" on JVC page.

What does "white clip extension" mean? How it enhance sharpness of the picture? Is it enhancing real details too?

raffriff42 · 20th August 2013, 01:52

VHS video is an FM signal. VHS has a defined sync level of 3.5 MHz and white level of 4.4 MHz. Colors whiter than white (for overshoot purposes) require a higher maximum frequency. I'm guessing as video tape improved, later VHS decks could record higher frequencies, allowing more overshoot. This would make the highlights a little less blown out - which is not actually "sharper." Maximum resolution is not affected, only white clipping.

marquis · 21st August 2013, 00:08

This might be a stupid question, but could this exist if you were to record with black and white? Even if it were a new black and white VHS opposed to the older tapes?

raffriff42 · 21st August 2013, 00:11

Yeah, some cameras overshoot like a motorboater.

19th August 2013, 22:47	#1 \| Link
infoeater Registered User Join Date: May 2007 Posts: 53	"white clip extension" in VHS HQ, what does it mean While reading article on Wikipedia I found a term "white clip extension". Google find only many copies of Wikipedia article. I found that "extension of the white clip level (...) sharpens the picture" on JVC page. What does "white clip extension" mean? How it enhance sharpness of the picture? Is it enhancing real details too? Last edited by infoeater; 20th August 2013 at 14:25.

20th August 2013, 01:52	#2 \| Link
raffriff42 Retried Guesser Join Date: Jun 2012 Posts: 1,373	VHS video is an FM signal. VHS has a defined sync level of 3.5 MHz and white level of 4.4 MHz. Colors whiter than white (for overshoot purposes) require a higher maximum frequency. I'm guessing as video tape improved, later VHS decks could record higher frequencies, allowing more overshoot. This would make the highlights a little less blown out - which is not actually "sharper." Maximum resolution is not affected, only white clipping. Last edited by raffriff42; 20th August 2013 at 02:54.

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21st August 2013, 00:08	#3 \| Link
marquis Registered User Join Date: Aug 2013 Posts: 10	This might be a stupid question, but could this exist if you were to record with black and white? Even if it were a new black and white VHS opposed to the older tapes?

21st August 2013, 00:11	#4 \| Link
raffriff42 Retried Guesser Join Date: Jun 2012 Posts: 1,373	Yeah, some cameras overshoot like a motorboater.