Strange banding in photo

Hi, A friend asked me what might cause this banding in his photo, which he took on his 450D. I immediately thought it was pixelation from taking the image on a small setting or something similar, but he assured me that it was taken on his highest setting. Could someone please take a quick look at it for me and tell me what you think? I've listed the metadata in the second link.

Also, he mentioned he used a circular polariser, but although this would explain circular rings in an image, I wouldn't think that it would give that "chunky" appearance. Surely this is a data issue?

http://2.bp.blogspot.c​om …pig36k/s1600-h/Sun+02.JPG

http://3.bp.blogspot.c​om …XI34/s1600-h/metadata.jpg

It may have been taken at the highest settings but it has been saved heavily compressed. This is probably what has caused the posterisation.

It is some kind of posterization.

http://www.cambridgein​colour.com/tutorials/p​osterization.htm
http://en.wikipedia.or​g/wiki/Posterization
http://www.adobeforums​.com/webx/.59b638df

*edit* beaten to it!

Was the image saved as a .gif? This will reduce the number of colours to 256 and cause this.

LeuceDeuce wrote in post #7541556
Was the image saved as a .gif? This will reduce the number of colours to 256 and cause this.

Yes, you'd be better to save as a jpeg.

That's not banding, it's jpeg artifacting. Posterization.

And no surprise - it's a 1600 X 1067 picture that's been compressed to only 174K!

You just can't do that and get reasonable quality.

-js

Thanks guys. POTN strikes again, and you're your usual extremely helpful (and fast) selves whenever I have a question!

When I saw the size of his photo, I immediately presumed he had saved the file again on his computer after resizing or something, but I think you are right: he must have his compression settings set too high on his camera, thus the teeny tiny file. I've relayed your info back to him (it's my husband's colleague) and I'm finding out if that is indeed what he did. I'll let you know the outcome. If it isn't the setting, then we might be dealing with a different kettle of fish.

keenasmustard wrote in post #7543959
Thanks guys. POTN strikes again, and you're your usual extremely helpful (and fast) selves whenever I have a question!

When I saw the size of his photo, I immediately presumed he had saved the file again on his computer after resizing or something, but I think you are right: he must have his compression settings set too high on his camera, thus the teeny tiny file. I've relayed your info back to him (it's my husband's colleague) and I'm finding out if that is indeed what he did. I'll let you know the outcome. If it isn't the setting, then we might be dealing with a different kettle of fish.

Don't think so. There's no setting that will give that much compression in-camera, so I figure it was done in PP.

-js