Canon 7D: strong moire problem in video mode?

THX1965

Is what I am seeing here a "normal" moire problem or is something wrong with my camera's sensor?

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Below is a detailed reference picture of the same 2 house walls that caused these strange artifacts in my 1080p test footage.

I read some reports about moire problems with the 7D, but I am not sure if this is in fact what I am seeing in my test video. If that was the case, it would mean - video of red brick houses - better not shoot those with a 7D...... There goes Great Britain.....

I'd raelly be grateful for any help. Should I be contacting Canon customer service?

Thanks in advance.

--- Markus ---

photokandy

Unless I'm mistaken, I believe the 7D does not use the entire sensor when capturing video; instead, it only uses certain rows from the sensor to build the image, which means that anything that has straight lines like your house is going to exhibit aliasing and odd patterns as you move the camera.

There's nothing wrong with the camera, however unpleasant the results may be -- it's just the way dSLR video works at the moment. Until Canon can figure out a way to pull the entire image, down-sample it, and encode it in less than 1/24 or 1/30 of a second, we're stuck with pulling certain rows and encoding them.

You might be able to do some creative post-processing to reduce the effect, but I'm not a video editing export, so I'm not sure.

THX1965

photokandy wrote:

Unless I'm mistaken, I believe the 7D does not use the entire sensor when capturing video; instead, it only uses certain rows from the sensor to build the image, which means that anything that has straight lines like your house is going to exhibit aliasing and odd patterns as you move the camera.

There's nothing wrong with the camera, however unpleasant the results may be -- it's just the way dSLR video works at the moment. Until Canon can figure out a way to pull the entire image, down-sample it, and encode it in less than 1/24 or 1/30 of a second, we're stuck with pulling certain rows and encoding them.

You might be able to do some creative post-processing to reduce the effect, but I'm not a video editing export, so I'm not sure.

Thanks for your comment, Kerri. Maybe it's more than a simple moire problem. I went ahead today and did some more test shooting. This time in 720p mode. I was quite shocked. There were thick, horizontal, "invisible" scan lines from top to bottom, distorting the image whenever I moved the camera up or down a bit. Really bad. This has nothing to do with some aliasing or some normal moire behavior. I am thinking I have a defective sensor. Now, I have not posted this 720p clip yet, since I want to be fair and give Canon a chance to resolve this issue. I am already in contact with their tech support. I'll keep posting updates to this forum.

THX1965

Canon says the camera needs repair. So I returned it to B+H today in exchange for a new one.