Another dumb question

[robertdrake]

This morning I went to the park with my wife and son and took a bunch of test shots with my 17-40L, came home and loaded them in my computer. I noticed that the right side of my wife's brown jacket looked very odd, like the colour had been painted on (almost pixalized) at 100%. Same with some shots of ducks, everything else looks fine. Now, I took the shot of one of the ducks, cropped it, processed it into PSE3, and viewed it as far as 200% and the distortion was gone. Now, I'm wondering if it has to do with being an unprocessed RAW file? Are they that distorted? If the answer is no, I can upload a pic to get your feedback.

BTW, the issue with the noisy focus was solved. A local guy who reads one of the forums came over with his, and his was just as noisy (guess some people just don't have good hearing).

[DaveG]

This morning I went to the park with my wife and son and took a bunch of test shots with my 17-40L, came home and loaded them in my computer. I noticed that the right side of my wife's brown jacket looked very odd, like the colour had been painted on (almost pixalized) at 100%. Same with some shots of ducks, everything else looks fine. Now, I took the shot of one of the ducks, cropped it, processed it into PSE3, and viewed it as far as 200% and the distortion was gone. Now, I'm wondering if it has to do with being an unprocessed RAW file? Are they that distorted? If the answer is no, I can upload a pic to get your feedback.

BTW, the issue with the noisy focus was solved. A local guy who reads one of the forums came over with his, and his was just as noisy (guess some people just don't have good hearing).

I suspect that your problem is an example of moire.

If there's a pattern in your wife's jacket (the way that the material is woven for example) at just the right angle and enlargement it's going to become sympathetic to the pitch of your computer's monitor. Then you get these funny crosshatch patterns that disappear if you make the image bigger or smaller. It is NOT in the file, and if you had it printed at that resolution it would not show up at all. I know that it's a bit disconcerting when you see it, and especially if you don't know what it is. Anyway that's my guess.

[robertdrake]

What's causing it? It doesn't seem to show up with my 50mm 1.8 lens, but does with this 17-40L. If its the lens, is it just normal for it or a defect? Or are you saying its just the interaction of the image and the monitor? I'm a bit confused.

[DaveG]

What's causing it? It doesn't seem to show up with my 50mm 1.8 lens, but does with this 17-40L. If its the lens, is it just normal for it or a defect? Or are you saying its just the interaction of the image and the monitor? I'm a bit confused.

If it is moire and I think that it is, it's a combination of the pattern in your shot combined with the size you are looking at it on your monitor.

The reason that you see it with your 17-40 and not your 50 is a dumb fluke. The jacket was turned in exactly the right direction with the zoom and wasn't with the 50. Tomorrow it could be the other way around. I find that I run into moire problems when I shoot H&S shots and the guy is wearing a checked jacket. But it's NOT the image, it's just the way the image - at that size - is interacting with the monitor.

Do a Google search for moire and I'm pretty sure that you can find some examples. Maybe your problem is something different, but until moire is excluded that's where my money is.

[jimsolt]

If it is moire, and I agree, it sounds like it, it is often the aforementioned circumstances that cause it. One way to lessen or eliminate it is to unsharpen the focus a little. I concur that if you are printing the photo, you will probably not see it. If you try to unsharp the focus for viewing on your monitor, and it works, try a test print and see which way you want to go.

[robertdrake]

If it provided a link to the unalterned .cr2 file, would you be able to download it and have a look?

[DaveG]

If it provided a link to the unalterned .cr2 file, would you be able to download it and have a look?


That would be a good idea.

[robertdrake]

Here it is http://www3.telus.net/public/alexlind/IMG_0288.CR2 . I notice it in EOS Viewer and PSE3, but not DPP. You see it at 100% on the right side shoulder.

[DaveG]

Here it is http://www3.telus.net/public/alexlind/IMG_0288.CR2 . I notice it in EOS Viewer and PSE3, but not DPP. You see it at 100% on the right side sholder.

No it's not there at all. I looked at the image with the exposure pulled down so that there was no highlight or shadow clipping on the RAW histogram, and then I did a second and changed it so that I could see shadow detail on HER left shoulder. In both exposure choices I saw no problems, including no moire. Now the reason that you might be seeing moire while I'm not, might just have to do with the dot pitch of my monitor compared to yours.

Anyway there's nothing wrong with this shot as I see it.

[robertdrake]

Oh...okay. I just got this monitor as a RMA refurb, so it could be that. What editing program did you use? It didn't show any problems in Digital Photo Professional but did in EV and Photoshop Elements. It looks like someone had painted black streeks across my wife's jacket arm. Same with my son's black pants in another image. Time for a new monitor.

[DaveG]

Oh...okay. I just got this monitor as a RMA refurb, so it could be that. What editing program did you use? It didn't show any problems in Digital Photo Professional but did in EV and Photoshop Elements. It looks like someone had painted black streeks across my wife's jacket arm. Same with my son's black pants in another image. Time for a new monitor.

I used Photoshop CS to process the RAW file. And no streaking at all.

[robertdrake]

Its the unprocessed file that has the problem, when I process it, no problem.

[CyberDyneSystems]

It sounds like monitor/monitor settings or a combination of the two.

[robertdrake]

Thanks again guys!