Yuck! banding

[Yang Wen]

Was reviewing footage from a recent wedding and all of the dance footage at the reception had this nasty moving bands crawling upwards in the vertical direction.. Pretty high frequency too, probably 20 of them in the frame at any given time. I was probably shooting at at lease 3200 ISO. The banding was more noticeable in the mid tone region where the band was darker than the image behind it... so it's not shadow only banding.

Anyone notice this image abnormality? Or is it normal for 5D2?

[Adam Berman]

The only time I've seen banding is:

When the sharpness is set too high.
The shutter speed is too high.
Photographers using a lot of flash will show up as bands across your video due to the CMOS rolling shutter.

Other than that, I haven't seen any strange banding.

Hope you can figure out what's causing it.

Originally Posted by Yang Wen

Was reviewing footage from a recent wedding and all of the dance footage at the reception had this nasty moving bands crawling upwards in the vertical direction.. Pretty high frequency too, probably 20 of them in the frame at any given time. I was probably shooting at at lease 3200 ISO. The banding was more noticeable in the mid tone region where the band was darker than the image behind it... so it's not shadow only banding.

Anyone notice this image abnormality? Or is it normal for 5D2?

[Tom Daigon]

Ive seen banding under flourescent lights.

[Yang Wen]

Adam: I'm not talking about the CMOS flash tear.. is that what you're referring to?

I'm talking about slow crawling dark bands..

Tom: Yes fluorescent lights will create banding, but I don't think they produce bands as high frequency as what I've described.. What I saw almost looks like interference from an outside source..

This is pretty much the type of banding I see in my video, except the bands are horizontal and they crawl upward..

http://photo.net/canon-eos-digital-camera-forum/00TtZZ

[Evan Donn]

Are you talking about a few large, dark bands? I ran into this once with the 70-200 f/2.8 IS - if I had the vignette compensation (forget exactly what it's called) turned on and pointed it at a bright area I could see 3-4 noticeable dark horizontal bands across the image. With compensation turned off they went away - I didn't pursue it further as it was a borrowed lens that I haven't used much since.

[Daniel Browning]

Originally Posted by Yang Wen

Anyone notice this image abnormality?

Yes, I deal with variable pattern noise all the time on the 5D2.

Originally Posted by Yang Wen

Or is it normal for 5D2?

Yes, it is completely normal. The visibility of banding is affected by the amount of light and the amount of amplification. Specifically:

• Exposure in all three channels (red, blue, and green).
• ISO setting (AKA analog and digital gain)
• HTP (affects ISO and digital gain)
• White balance (digital gain in some channels).
• ALO (digital gain in dark parts of the image).
• Picture profile

You were shooting a reception in low light, so the exposure is low and ISO is high. The light source was probably Tungsten, which means the blue channel was ISO 12800 while red and green were ISO 3200. If you had ALO enabled, that could have pushed the blue channel to the equivalent of ISO 25600 in some parts of the image.

I should also mention that there are cases where RF interference can exacerbate variable pattern noise (such as with a cheap flash).

The best solution is to increase exposure. (The 5D2 has good performance in low light, but it has limits, and the pattern noise tells you when you're hitting them.)