CMOS versus CCD at DVinfo.net

Andreas Nistler · February 23rd, 2008, 06:46 PM

I'm a news photog, currently using the JVC GY-HD100. I'm planning to switch to the S270 because the JVC produces vertical smear on bright light sources, and going tapeless via Firestore HDD is not very relyable.

Now I've read that CMOS may exhibit skew, wobble and partial exposure because of "rolling shutter" technology. CMOS can use either “rolling” or “global” but as a practical matter all the camcorders on the market use the “rolling shutter” technology. See http://dvxuser.com/jason/CMOS-CCD/.

If the S270 demands controlled lighting avoiding any motion (always tripod mounted, never handheld) it's useless for news gathering.

Does anyone know, what kind of "shutter" the S270 uses? And if it uses a "rolling shutter" how noticeable those artifacts are?

Thanks in advance,
Andreas

Laurence Kingston · February 23rd, 2008, 07:50 PM

The 270 is CMOS so it theoretically should have the rolling shutter effect as well. In actual practice I have never had a problem but I have seen the effect on fast camera movement that I would have edited out anyway.

Both CCD and CMOS have their advantages and disadvantages: verticle smear for CCD vs. rolling shutter for CMOS. Nothing is perfect.

Greg Boston · February 23rd, 2008, 09:03 PM

High quality CCD's have very little vertical smear, but they are on higher priced cameras.

The EXMOR CMOS sensors that Sony is using show a lot less rolling shutter than you would think because of the way they read out the sensor.

Just remember, the RED camera also uses CMOS as a sensor and it's doing just fine in the image department.

-gb-

Bill Ravens · February 23rd, 2008, 10:31 PM

I've got a JVC HD110 and a Sony EX1. Most of the stuff I shoot is vast panoramas. Not a lot of motion in the images outside of the pans I induce. Still, I like the EX1 over the JVC hands down. The skew in motion on the EX1 is NOT noticeable.

Jack Zhang · February 24th, 2008, 12:01 AM

The only big concern is if you plan to do a handheld matchmove. CCDs are best suited for that.

Andreas Nistler · February 24th, 2008, 06:22 AM

So I should not be worried too much about skew and wobble...

Last concern is "partial exposure": What about press conferences, where a lot of still photogs use their flashes?

If it looks like http://www.freshdv.com/mjeppsen/vide...r_artifact.mov I'll stay with CCD...

Martin Sonnenberg · February 29th, 2008, 10:54 PM

Quote:

What about press conferences, where a lot of still photogs use their flashes?

I have used a V1U (CMOS) at dozens of media events for this year's presidential campaign in the U.S. And yes, the rolling shutter effect is real.

That said it is most obvious when stepping through frame by frame and a quarter to half of an image on a frame or adjoining frames is missing.

Mind you it is not a constant with the hundreds of flashes going off, but rather occasional and random, (several events have had 50 or more electronic crews and as many still photogs.)

The effect at speed, looks like a flash went off, and not unlike the flash frames seen when shooting 16mm film. It is not something that would automatically warrant plugging in a cuttaway.

Of course, there's a little voice that says, "what if the one frame where something extraordinary happens is the random frame and you know a still guy got the shot..."

I'd like shoot with the if the s270 in the field before deciding if it would be my primary camera. The next step is the XDCam for CCD 1/2 or 2/3 chips.

Andrew Kimery · March 7th, 2008, 01:17 PM

I just worked w/some red carpet footage shot w/a V1U and the partial exposure problem was pretty bad. One person who saw it said it looked like the camera was malfunctioning. Single, intermittent flashes going off might not look too bad, but on a red carpet w/flashes going off like crazy (and those "red eye reduction" pre-flashes) you start to get some insane looking banding as the different flashes catch the electronic shutter at different points in its "roll".

If you are doing a lot of events like these I'd stay away from CMOS cameras until they improve the tech (like implementing a global shutter).

-A

Sulev Sepp · March 11th, 2008, 04:22 AM

Hi all,

I need to buy new camera. New Sony S270 spec looks good. One serious detail to think: CMOS "rolling shutter" issue. I do filming on receptions and on other events where photo flashes and fireworks are 100% part of event.
Have You sample footage from event ( like I described) or have You seen Sony's own sample footage. For example interesting object is waterfall under light.
Please feedback!

With
Best
Sulev

February 23rd, 2008, 06:46 PM	#1
Andreas Nistler Regular Crew Join Date: Dec 2006 Location: Germany Posts: 28	CMOS versus CCD I'm a news photog, currently using the JVC GY-HD100. I'm planning to switch to the S270 because the JVC produces vertical smear on bright light sources, and going tapeless via Firestore HDD is not very relyable. Now I've read that CMOS may exhibit skew, wobble and partial exposure because of "rolling shutter" technology. CMOS can use either “rolling” or “global” but as a practical matter all the camcorders on the market use the “rolling shutter” technology. See http://dvxuser.com/jason/CMOS-CCD/. If the S270 demands controlled lighting avoiding any motion (always tripod mounted, never handheld) it's useless for news gathering. Does anyone know, what kind of "shutter" the S270 uses? And if it uses a "rolling shutter" how noticeable those artifacts are? Thanks in advance, Andreas

March 11th, 2008, 04:22 AM	#9
Sulev Sepp New Boot Join Date: Apr 2006 Location: Tallinn, Estonia Posts: 20	HVR-S270 rolling shutter Hi all, I need to buy new camera. New Sony S270 spec looks good. One serious detail to think: CMOS "rolling shutter" issue. I do filming on receptions and on other events where photo flashes and fireworks are 100% part of event. Have You sample footage from event ( like I described) or have You seen Sony's own sample footage. For example interesting object is waterfall under light. Please feedback! With Best Sulev

February 23rd, 2008, 07:50 PM	#2
Laurence Kingston Major Player Join Date: Aug 2004 Location: Clermont, FL. Posts: 941	The 270 is CMOS so it theoretically should have the rolling shutter effect as well. In actual practice I have never had a problem but I have seen the effect on fast camera movement that I would have edited out anyway. Both CCD and CMOS have their advantages and disadvantages: verticle smear for CCD vs. rolling shutter for CMOS. Nothing is perfect.

February 23rd, 2008, 09:03 PM	#3
Greg Boston Wrangler Join Date: Oct 2003 Location: DFW area, TX Posts: 6,117 Images: 1	High quality CCD's have very little vertical smear, but they are on higher priced cameras. The EXMOR CMOS sensors that Sony is using show a lot less rolling shutter than you would think because of the way they read out the sensor. Just remember, the RED camera also uses CMOS as a sensor and it's doing just fine in the image department. -gb-

February 23rd, 2008, 10:31 PM	#4
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	I've got a JVC HD110 and a Sony EX1. Most of the stuff I shoot is vast panoramas. Not a lot of motion in the images outside of the pans I induce. Still, I like the EX1 over the JVC hands down. The skew in motion on the EX1 is NOT noticeable.

February 24th, 2008, 12:01 AM	#5
Jack Zhang Inner Circle Join Date: May 2005 Location: Burnaby, BC, Canada Posts: 3,053	The only big concern is if you plan to do a handheld matchmove. CCDs are best suited for that.

February 24th, 2008, 06:22 AM	#6
Andreas Nistler Regular Crew Join Date: Dec 2006 Location: Germany Posts: 28	So I should not be worried too much about skew and wobble... Last concern is "partial exposure": What about press conferences, where a lot of still photogs use their flashes? If it looks like http://www.freshdv.com/mjeppsen/vide...r_artifact.mov I'll stay with CCD...

March 7th, 2008, 01:17 PM	#8
Andrew Kimery Major Player Join Date: Aug 2005 Location: Los Angeles Posts: 352	I just worked w/some red carpet footage shot w/a V1U and the partial exposure problem was pretty bad. One person who saw it said it looked like the camera was malfunctioning. Single, intermittent flashes going off might not look too bad, but on a red carpet w/flashes going off like crazy (and those "red eye reduction" pre-flashes) you start to get some insane looking banding as the different flashes catch the electronic shutter at different points in its "roll". If you are doing a lot of events like these I'd stay away from CMOS cameras until they improve the tech (like implementing a global shutter). -A