Strange Flickering and Green Flashes.

A

azman

Member
Hi Everyone,

I shot a wedding recently using HMC152. Encountered some artifacts that I've not come across before in previous shoots.

The solemnization ceremony was held indoors. Lighting was a mixture of halogen and fluorescent.

I used manual white balance.
Camera encoding rate was set to HA1080/50i

I shot several more weddings before this with similar lighting conditions.

At this wedding, all (yes, all) of the footages showed some flickering, some with flashes of green. Although there were many flashes from DSLRs and compacts going off, I don't think they caused the flickers.

These flickering were not apparent on the camera LCD during the shoot but appeared on the LCD upon playback.

Here's a sample of one of the footages. http://www.youtube.com/watch?v=SZcSPuhPEls

My camera settings were the same for all the weddings except this one because at the end of this shoot, I discovered that I've accidentally set the shutter speed to 1/50 whereas I've left the shutter setting at default for all the previous wedding shoots.

Could this be the cause of the flickers ? Has anyone encountered this before ?

Sincerely,
Azman
 
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I don't think that could be caused by settings -- that looks to be data corruption. I think you have a problem somewhere in the chain -- either a bad card, or a bad camera, or a bad copy to the computer.

Do you still have the footage on the original card? Can you play it back to a TV, and does it happen there? Or only after it's been transferred to the computer?
 
Thanks Barry for the quick reply.

Normally, what I always do ( I think most of us do this as well ) is to arrive early at a shoot and do some test shots. When I reviewed the test shots, I did notice flickers when viewing the shots on the camera LCD. However, the flickers were not seen on the LCD while shooting. I did not think much of it at first.

But when I reviewed some shots during some breaks in the ceremony, I saw that all the shots that I looked at have at least one flicker in them.

I do not have them in the card anymore, unfortunately. And I don't remember which card I used to take the shots with. I have 3 of them. All are Class 6 Transcend 16GB.

Once I get off from work later I'll try to take some test shots using the cards with the shutter set at 1/50 and see if the flickers appear again.

Will let you know once I've done it. Thanks again Barry :)
 
I shot some clips using all 3 cards last night using the same settings I used during that wedding shoot and I also set the shutter speed to 1/50sec

Unfortunately or fortunately none of the clips show any flicker when viewed from the camera LCD nor after transcoding into the computer.

Some additional info: I've shot 2 more events (indoors and outdoors) after that particular wedding shoot using all three of my Transcend SD cards and none of the clips showed any flickering.

Barry, assuming the flickers were due to a bad card or a glitch in the camera, what precautions do you recommend ?
 
Sounds again like someone having problems with Transcend?! Hmm... strange.

For me it doesnt have anything to do with FLash-Lights or stuff like that... seems to be like a codec-problem or an card issue or something between that both.

Have u formatted the Cards before your shooting inside the camera?
Did u made a Black-Balance?

You could mark your cards like Card1, Card2, Card3... and if you get an problem again, you know which card is making trouble and could check it/send it back...
 
Thanks :) I'll label the cards ASAP.

I've had one of the Transcend cards for almost 2 years and the other 2 for about 6 months. This is the first time I have this problem.

I always format all the cards the night before the shoot. What effect does Black-Balance have on the clips ? I've not done that before.
 
While I doubt it is part of the flickering issue, Black Balance could be considered essential for the color balance of your shots. It's recommended that you do a BB every time you turn-on the camera. It only takes a few seconds.

-vic
 
Thanks Vic. I'll give the BB a try :)

On the flickers issue...

I received an email from a friend who uses an HMC152 also. He said he also encountered green flickers before.

However, according to him, the flickers did not appear on the camera LCD upon playback but only appeared after he transcoded the clips into the computer using Vegas.

He uses Panasonic 16GB Class 6 SD cards.
 
My friend was using Vegas when he encountered the flickers.

As for me, I was using Final Cut Pro 7 but the flickers were already there before I trancoded them into FCP.
 
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