can anyone tell me what causes this??

First time I've seen this - can anyone tell me what causes it?

Ta

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either you took a picture of a dog on tv, or you used a plaid scarf as a filter.

It looks somewhat like the "Horizontal Banding" issue that plagues come camera/lense/setting combinations. Unfortunately this looks like both horizontal and vertical. Try the same shot (with or without the dog, of course) under controlled conditions and see if you can duplicate the error. Especially try it in aperture priority instead of shutter priority.

Also, Google search [+Canon +"horizontal banding"]

Rad

I have seen the same thing when I have really under exposed a RAW file. I shoot mostly RAW+jpeg and the jpeg would be completely black and RAW is trying to get anything out of it.

I think Atomic has a point. It looks like it was also shot with very high ISO.

This is absolutly noise caused by an under exposed image as Atomic79 mentioned and not a banding issue. I have seen this exact same issue on an number of occasions with shots in low light situations.

There is no evidence that that is the case here. When a RAW is pushed that far, color veracity and contrast is sacrificed. For example, I would have expected the white (beige, actually) behind the dog to have been completely blown, especially where the fur of his right ear and cheek overlay the beige. That did not happen here. Also, the brightness and contrast subtleties on his face and eyes are appropriate. Nothing blown. Again, if it were pushed, don't you think the highlights would have been blown?

Exactly just how "very high" is 100?

Boy, I am glad that we have that absolutly [Sic] figured out. But still, I wonder how can you call this "an under exposed image" - any more exposure and the highlights would have been blown. Does this much noise really seem appropriate at 100 iso?

tantalus1662, remember this, if you ask 3 different people the same question, you're gonna get 5 different answers. AND, the advice you find on the Internet is worth exactly what you pay for it, nothing! So do your own testing. Same setup, same technical factors, same parameters, then switch one factor (shutter speed, aperture, iso) one at a time, then switch one parameter (Tv, Av, Full Manual, Auto Focus, Manual Focus) and keep track of the changes.

If it is a banding issue, (caused by interference from the on-board computer) a parameter change will affect what you see because the interference is expressed only under a specific set of circumstances.

If is it a common noise issue, is will disappear with a technique change - specifically a technique that gives you a higher exposure - IE, longer exposure time or wider aperture. But if it is noise, that is way too much noise for 100 iso and you have a bollocksed up sensor.

Rad

No need to get "pissy". It is my opinion that this is not a banding issue. Although the ISO is set to 100 it does not mean that you will never see noise. The fact is that I have seen exact same issue lots of times with under exposed images. This is not an equipment problem. (that is my final opinion and answer. I am sorry if my opinion offended you in any way! But hey we are all entitled to our opinions aren't we.

doesn't look like banding, It seems more like noise.
If you under expose, expecially with high ISO (which is more noisy to begin with) and try to recover detail from under exposed area, you get a lot of noise, color and pattern. That's what it looks like to me. No matter what the ISO, if you try to recover detail you will get noise, it's just a matter of degree, lower ISO gives more room to spare, but everything has limits.

Perhaps the OP can post the pre processed shot. I think banding presents prior to any processing, could be wrong here though.
Banding also look like just that, bands, either horizontal or verticle and exists in area of high with low contrast. When I underexpose and try to recover the detail in RAW, this is exactly what I get. Especially so with the 1.6x cropped sensors.

Here's Phil's take on banding in Canon's at dpreview. You can click on the image and get fullsized ones. The shadow area under the mouse shows banding in the shadow area where there is high contrast from light color of the mouse to the shadow caused by the mouse.
As you can see, it only occurs in the shadow area and mainly consists of horizontal bands vs the checkering we see here. His current thought is that it's the AI Servo motor causing interference, though I've seen guys post banding just like this taken with MF lenses as well.

Hey, I think I've coined a new term "Checkering" means horizontal and verticle grid like pattern noise with color noise throughout the image from attempting to pull detail out of underexposed areas. Expose to the right...
http://www.dpreview.co​m …ws/canoneos30d/​page22.asp

The image posted was not processed one little bit - RAW straight from the camera converted into JPEG for posting. The banding was present on the LCD screen on the camera before being downloaded.

The picture was shot in the shade (probably on sunny WB setting as I had just been in the garden with the dogs (piccies to follow)) on 100 ISO.

All I really want to hear is that it is not an equipment problem! I will try tomorrow, same position, same zoom but mess around with the ISO, shutter and aperture.

Do the above comments help any of you tell me what this is?????

It looks like an underexposed raw image that was opened in ACR with auto settings on. I bet that if you open the image up in ACR, and use Ctrl-U to turn off the auto settings, you'll see a much darker image. I've seen this myself, and it has been documented recently in another thread. The problem stems from not using a high enough ISO setting - the commonality that most images that look like this are low light and low ISO.

Radtech1, before you damn the possible root causes, try taking a very underexposed picture in raw, and "push" it in ACR. You'll see a similarity.

Having thought about it....... I think it is noise. Like I say, I probably forgot to switch WB setting after being on sunny. I was under shade and the dog was sitting just inside a garage so even darker. Will still experiment tomorrow as on a steep learning curve at the moment!!

Still, got some great pics of both my dogs today. Will post when had time to sort through them. Took upward of 80 pics, 15 of which will probably be the pick of the best - dont you just lurve digital!

WB has nothing to do with it. Look at the Exposure slider.

Can you send me the RAW file to review? This is peaking my curiosity
dr_yi@hotmail.com
WB setting will make the image look really yellow or blue but should not effect noise or patterns/banding.
BTW, why do people use automatic correction settings in RAW?

Is it possible to get to a jpeg from raw without processing? This is exactly what my grossly underexposed images look like when I try to recover them. Either that or it was shot thru some kind of screen door.

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