Still camera woes at DVinfo.net

Mike Rehmus · March 25th, 2006, 01:43 PM

Have you taken video footage at an event and found mysterious hatch & picket fence patterns in your footage?

Welcome to the digital camera world.

Especially with the higher-end digital still cameras, in dim surroundings, they project an IR pattern so the camera can focus. CCD sensors, even with the IR filter in place, are more sensitive to IR than to visible (to us) light. The DSLRs with their add-on flashes cause even more problems because the flash may project a much stronger pattern in dim light.

I had one wedding video nearly ruined by this problem. It was a fairly uncontrolled wedding at a resort and the guests were allowed to walk up on stage and take pictures during the event. (bunch of police officers, no shy violets them). The result was the frequent appearance of strange white lines crossing the wedding party and anything within range.

The bride and groom were understanding but it is not a wedding I have in my sample book.

Fortunately, most wedding photographers (stills) tend to use manual focus so the IR isn't turned on. But you should check before the event and have a discussion with the B&G about the problem. They can ask people not to take pictures during specific events in the wedding.

Chris Hurd · March 26th, 2006, 11:36 PM

Excellent topic, Mike! I've moved it from your VX2100 forum to the Wedding / Event Video area.

Greg Boston · March 27th, 2006, 05:57 AM

Quote:

Originally Posted by Mike Rehmus

Have you taken video footage at an event and found mysterious hatch & picket fence patterns in your footage?

Welcome to the digital camera world.

Especially with the higher-end digital still cameras, in dim surroundings, they project an IR pattern so the camera can focus. CCD sensors, even with the IR filter in place, are more sensitive to IR than to visible (to us) light. The DSLRs with their add-on flashes cause even more problems because the flash may project a much stronger pattern in dim light.

I had one wedding video nearly ruined by this problem. It was a fairly uncontrolled wedding at a resort and the guests were allowed to walk up on stage and take pictures during the event. (bunch of police officers, no shy violets them). The result was the frequent appearance of strange white lines crossing the wedding party and anything within range.

The bride and groom were understanding but it is not a wedding I have in my sample book.

Fortunately, most wedding photographers (stills) tend to use manual focus so the IR isn't turned on. But you should check before the event and have a discussion with the B&G about the problem. They can ask people not to take pictures during specific events in the wedding.

Yes Mike, I have had this show up on a wedding video I did. Although my lines and patterns appeared as a dim red color. The give-away was the ensuing flash after the pattern disappeared. Fortunately, these were post ceremony posed shots that I was videoing so it wasn't a major problem to edit out.

-gb-

Peter Jefferson · March 27th, 2006, 06:16 AM

its funny, ive done shoots where teh guests were like papparazzi and no shit, were talking 30odd cameras flashes pounding away here.. ALL NIGHT LONG
but i have to say the camera of choice (DVX100's) doesnt show off any of these abherations. I think the only time it ws an issue was when i had the iris set to auto by accident (tripoded unmanned camera) and it would respond by droping itself when the flashes went off.

One thing though, the dvx100a can shoot directly into any given light (Ikid u now) with virtually no distortion bar the incredible looking sun flare, the orignal 100 however has some issues with this..

i recently did a wedding which had a fire and ice theme and they had blue chasers and scanners all set up and the blue just totally killed EVERYTHING. were talking nightclub lighting rigs here, and even though the camera was white balanced, i THINK the CCD was overdriven somehow and it totally lost itself. Easy fix though, just face teh camera another direction.. ;)
The 100a however perfected beuatifully and during the dancing i shot AT the lights with people creating sillhouettes and shadows in the foreground (I used to shoot rave parties.. lol ) but yer... i was surprised at the performance.. but one thing i know fer sure, is that the Z1's would NOT be able to cope with this kind of light.. i remember once i was shooting an an indoor pool with an underwater light illuminating it.. and all i got from teh light refractions was a vertical smear.. totaly ugly

March 25th, 2006, 01:43 PM	#1
Mike Rehmus Wrangler Join Date: May 2002 Location: Vallejo, California Posts: 4,049	Still camera woes Have you taken video footage at an event and found mysterious hatch & picket fence patterns in your footage? Welcome to the digital camera world. Especially with the higher-end digital still cameras, in dim surroundings, they project an IR pattern so the camera can focus. CCD sensors, even with the IR filter in place, are more sensitive to IR than to visible (to us) light. The DSLRs with their add-on flashes cause even more problems because the flash may project a much stronger pattern in dim light. I had one wedding video nearly ruined by this problem. It was a fairly uncontrolled wedding at a resort and the guests were allowed to walk up on stage and take pictures during the event. (bunch of police officers, no shy violets them). The result was the frequent appearance of strange white lines crossing the wedding party and anything within range. The bride and groom were understanding but it is not a wedding I have in my sample book. Fortunately, most wedding photographers (stills) tend to use manual focus so the IR isn't turned on. But you should check before the event and have a discussion with the B&G about the problem. They can ask people not to take pictures during specific events in the wedding. __________________ Mike Rehmus Hey, I can see the carrot at the end of the tunnel!

March 26th, 2006, 11:36 PM	#2
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	Excellent topic, Mike! I've moved it from your VX2100 forum to the Wedding / Event Video area. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

March 27th, 2006, 06:16 AM	#4
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	its funny, ive done shoots where teh guests were like papparazzi and no shit, were talking 30odd cameras flashes pounding away here.. ALL NIGHT LONG but i have to say the camera of choice (DVX100's) doesnt show off any of these abherations. I think the only time it ws an issue was when i had the iris set to auto by accident (tripoded unmanned camera) and it would respond by droping itself when the flashes went off. One thing though, the dvx100a can shoot directly into any given light (Ikid u now) with virtually no distortion bar the incredible looking sun flare, the orignal 100 however has some issues with this.. i recently did a wedding which had a fire and ice theme and they had blue chasers and scanners all set up and the blue just totally killed EVERYTHING. were talking nightclub lighting rigs here, and even though the camera was white balanced, i THINK the CCD was overdriven somehow and it totally lost itself. Easy fix though, just face teh camera another direction.. ;) The 100a however perfected beuatifully and during the dancing i shot AT the lights with people creating sillhouettes and shadows in the foreground (I used to shoot rave parties.. lol ) but yer... i was surprised at the performance.. but one thing i know fer sure, is that the Z1's would NOT be able to cope with this kind of light.. i remember once i was shooting an an indoor pool with an underwater light illuminating it.. and all i got from teh light refractions was a vertical smear.. totaly ugly