Can you identify this?

[iamWZA]

http://i.imgur.com/kmOSr.jpg

This won't be a particularly interesting thread but will be very helpful for me, so thank you if you can help.
What are those lines in the background? Is it moire or aliasing or something else? How can I avoid it?

This was shot on a 550D. Perhaps it is just something you will get when shooting with lower end cameras. Is it less of an issue with more expensive cameras?
Thanks a lot

[Dustin Moore]

Someone removed all of the chrominance so what you are seeing is the steps between the luminance
values of an 8-bit (0 to 255) system. If you make the picture noisier (higher ISO) or don't remove all
of the chrominance it will be harder to see the steps.

[iamWZA]

It was me who shot and edited it. I don't even know what chrominance is and I don't remember removing it!
This is the original video - http://www.youtube.com/watch?v=vgmLD_cT3vA

Hope you like nipple hairs

[brynsank]

Chrominance is colour, essentially. You removed the colour to make it greyscale (or black & white).
That is a rather strange video if I may say so...

[brynsank]

The lines you are referring to are called banding, which as Dustin pointed out are related to bit depth. Banding is most obvious in situations like this with gradual, consistent tonal changes. It's not necessarily related to how expensive the camera is, but certainly there are more expensive cameras that record at higher bit-depths where the banding becomes less visible. You can reduce the effect of the banding by adding noise, or masking out the more obvious areas and applying some blur. Blur and subtle noise together would probably be ideal. And of course your method of compression in post also matters.