Shooting Projected Images w/ 7D at DVinfo.net

Nate Haustein · April 8th, 2010, 12:45 AM

Tonight I shot some footage for an advertisement for a HD projector with the 7D. When I pointed the camera at the screen, however, colored bars appeared over the image – a sync issue with the projector. The projector was displaying to a 60hz image, and the 7D was recording in 24p with a shutter speed of 1/60. Should work right? Not really.

I kept having problems and tried a number of different settings to try and remedy the issue. All of a sudden, it looked fine. When I came back 5 minutes later to test some more, the bars reappeared. My settings were 1/60, 1080p24.

What I figured out is that the camera only syncs with the projected images when turned on at exactly the right time. So, I kept flipping the on/off switch until it looked normal. Usually took 8-10 times to work. Not sure what the technical explanation is for this, but I thought I'd share in case someone is having a similar issue with recording projected images or perhaps television screens?

Joe Pleniukas · April 18th, 2010, 12:44 PM

Not sure if it would make a difference or not, but were you using the 7d with battery power, or with an AC adapter plugged into the same outlet as the projector?

I'll test this sometime soon when I have a free second.

-Joe

Nathan Moody · April 18th, 2010, 06:08 PM

Fellow Nate,

I've had similar issues trying to capture the work we do on Microsoft Surface, which has a short-throw rear-projection unit inside...trying to lock on sensible frame rates didn't really work. I've had to use the ClearScan abilities of my XH-A1 instead to shoot such footage...I didn't find a sensible workaround on my 7D.

Not saying there isn't a solution, but I don't think it's just you, if that helps at all. ;-)

Nate Haustein · April 18th, 2010, 06:14 PM

The 7D was on battery power, and set to 1/60, F1.8, and 1080p24. My XHA1 worked great first time at 1/60, but that's just not as sexy as the DSLR, so I chose to suffer instead. Luckily my actors (read good-natured friends) were patient with my flipping the cam on and off all the time.

Here's some quick and dirty pics from the FCP timeline to show what I'm talking about, one with the problem and one without the problem:

April 8th, 2010, 12:45 AM	#1
Nate Haustein Trustee Join Date: May 2007 Location: Minneapolis, MN Posts: 1,313	Shooting Projected Images w/ 7D Tonight I shot some footage for an advertisement for a HD projector with the 7D. When I pointed the camera at the screen, however, colored bars appeared over the image – a sync issue with the projector. The projector was displaying to a 60hz image, and the 7D was recording in 24p with a shutter speed of 1/60. Should work right? Not really. I kept having problems and tried a number of different settings to try and remedy the issue. All of a sudden, it looked fine. When I came back 5 minutes later to test some more, the bars reappeared. My settings were 1/60, 1080p24. What I figured out is that the camera only syncs with the projected images when turned on at exactly the right time. So, I kept flipping the on/off switch until it looked normal. Usually took 8-10 times to work. Not sure what the technical explanation is for this, but I thought I'd share in case someone is having a similar issue with recording projected images or perhaps television screens? __________________ Nate Haustein PXW-FX9 / FCPX www.flightcreativemedia.com

April 18th, 2010, 12:44 PM	#2
Joe Pleniukas Tourist Join Date: Apr 2010 Location: Topanga, CA Posts: 1	sync? Not sure if it would make a difference or not, but were you using the 7d with battery power, or with an AC adapter plugged into the same outlet as the projector? I'll test this sometime soon when I have a free second. -Joe

April 18th, 2010, 06:08 PM	#3
Nathan Moody Regular Crew Join Date: Feb 2009 Location: SF Bay Area, CA, USA Posts: 78	Fellow Nate, I've had similar issues trying to capture the work we do on Microsoft Surface, which has a short-throw rear-projection unit inside...trying to lock on sensible frame rates didn't really work. I've had to use the ClearScan abilities of my XH-A1 instead to shoot such footage...I didn't find a sensible workaround on my 7D. Not saying there isn't a solution, but I don't think it's just you, if that helps at all. ;-) __________________ designer of media for eyes and ears sound design and field recording at http://www.noisejockey.net/blog

April 18th, 2010, 06:14 PM	#4
Nate Haustein Trustee Join Date: May 2007 Location: Minneapolis, MN Posts: 1,313	The 7D was on battery power, and set to 1/60, F1.8, and 1080p24. My XHA1 worked great first time at 1/60, but that's just not as sexy as the DSLR, so I chose to suffer instead. Luckily my actors (read good-natured friends) were patient with my flipping the cam on and off all the time. Here's some quick and dirty pics from the FCP timeline to show what I'm talking about, one with the problem and one without the problem: Attached Thumbnails __________________ Nate Haustein PXW-FX9 / FCPX www.flightcreativemedia.com