Pan Jitter at DVinfo.net

Geoffrey Mee · July 29th, 2003, 04:17 PM

Has anyone heard of image jitter in the PAL model?
A friend was trying out the camera recently and said there was pan jitter.

Thanks
Geoffrey

Yang Wen · July 29th, 2003, 05:37 PM

yes, they all jitter, which is natural

Barry Green · July 29th, 2003, 07:16 PM

When using a slower frame rate (i.e., 24, 25, or 30 fps) you have to pan slower. That's the rule.

I adapted the American Cinematographer's Manual's acceptable panning rates to the DVX100's focal lengths. You'd be surprised how slow you have to pan, if you want the image to look glass-smooth.

The short rule of thumb is, it should take about 8 seconds for an object to cross the screen during a pan. Pans should be slow enough that the motion looks smooth on the camera's LCD.

The long, laborious table is as follows: to execute a 90-degree sweep, at the following focal lengths, at 24P or 30P frame rates, should take the following amount of seconds in order to look smooth:

FOCAL LENGTH / 24P PAN SPEED / 30P PAN SPEED
4.5mm / 15 seconds / 11 seconds
6mm / 18 seconds / 14 seconds
7mm / 21 seconds / 16 seconds
8mm / 23 seconds / 20 seconds
12mm / 36 seconds / 27 seconds
14mm / 50 seconds / 38 seconds
16.5mm / 60 seconds / 45 seconds
25mm / 80 seconds / 60 seconds
30mm / 90 seconds / 75 seconds
45mm / 120 seconds / 120 seconds

Stephen van Vuuren · July 29th, 2003, 08:57 PM

Great info Barry - thanks for the post. I've just being using my eyes in the LCD which is better than looking through a tiny Super8 or 16 viewfinder... :)

Your spot on about the 8 seconds - that's been my experience as well.

BTW. No Panny anamorphic for me. I'm going to wait for the CO. I don't have a project that will need the extra res in the next few months...

Jarred Land · August 2nd, 2003, 08:02 PM

BTW, the jitter you see on the LCD is not what is recorded to tape, the frame rate on the LCD is half the frame rate of normal speed as to free up processing power.

Stephen van Vuuren · August 2nd, 2003, 08:04 PM

Jarred:

Interesting - is that 12fps in 24p, 15fps in 30p - what about 60i?

Jarred Land · August 2nd, 2003, 08:08 PM

sorry... no need for the reduction in interlaced modes. More than enough power in 60i.

That is why the autofocus has been disabled as well in 24p and 30p modes.

July 29th, 2003, 04:17 PM	#1
Geoffrey Mee Tourist Join Date: Jul 2003 Posts: 2	Pan Jitter Has anyone heard of image jitter in the PAL model? A friend was trying out the camera recently and said there was pan jitter. Thanks Geoffrey

July 29th, 2003, 08:57 PM	#4
Stephen van Vuuren Space Hipster Join Date: Oct 2001 Location: Greensboro, NC Posts: 1,508	Great info Barry - thanks for the post. I've just being using my eyes in the LCD which is better than looking through a tiny Super8 or 16 viewfinder... :) Your spot on about the 8 seconds - that's been my experience as well. BTW. No Panny anamorphic for me. I'm going to wait for the CO. I don't have a project that will need the extra res in the next few months... __________________ stephen v2 www.insaturnsrings.com

August 2nd, 2003, 08:04 PM	#6
Stephen van Vuuren Space Hipster Join Date: Oct 2001 Location: Greensboro, NC Posts: 1,508	Jarred: Interesting - is that 12fps in 24p, 15fps in 30p - what about 60i? __________________ stephen v2 www.insaturnsrings.com

July 29th, 2003, 05:37 PM	#2
Yang Wen Major Player Join Date: May 2003 Location: Chicago, IL Posts: 991	yes, they all jitter, which is natural

July 29th, 2003, 07:16 PM	#3
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	When using a slower frame rate (i.e., 24, 25, or 30 fps) you have to pan slower. That's the rule. I adapted the American Cinematographer's Manual's acceptable panning rates to the DVX100's focal lengths. You'd be surprised how slow you have to pan, if you want the image to look glass-smooth. The short rule of thumb is, it should take about 8 seconds for an object to cross the screen during a pan. Pans should be slow enough that the motion looks smooth on the camera's LCD. The long, laborious table is as follows: to execute a 90-degree sweep, at the following focal lengths, at 24P or 30P frame rates, should take the following amount of seconds in order to look smooth: FOCAL LENGTH / 24P PAN SPEED / 30P PAN SPEED 4.5mm / 15 seconds / 11 seconds 6mm / 18 seconds / 14 seconds 7mm / 21 seconds / 16 seconds 8mm / 23 seconds / 20 seconds 12mm / 36 seconds / 27 seconds 14mm / 50 seconds / 38 seconds 16.5mm / 60 seconds / 45 seconds 25mm / 80 seconds / 60 seconds 30mm / 90 seconds / 75 seconds 45mm / 120 seconds / 120 seconds

August 2nd, 2003, 08:02 PM	#5
Jarred Land DVX User Join Date: May 2003 Location: Vancouver Posts: 281	BTW, the jitter you see on the LCD is not what is recorded to tape, the frame rate on the LCD is half the frame rate of normal speed as to free up processing power.

August 2nd, 2003, 08:08 PM	#7
Jarred Land DVX User Join Date: May 2003 Location: Vancouver Posts: 281	sorry... no need for the reduction in interlaced modes. More than enough power in 60i. That is why the autofocus has been disabled as well in 24p and 30p modes.