Moire Patterns?

[Earl_B]

All,

Sorry this is going to long. This post will be a test of your patience with a newbie that is just starting to take pictures with a decent camera. [img]/ubbthreads/images/graemlins/smile.gif[/img]

I received my Canon EOS Digital Rebel two days ago. Prior to that, I had never played with things like White Balance, F-stop, shutter speed, etc. I am reading eveything I can, but I definitely have a lot to learn.

That being said ... I took the camera to church today because I was asked to take some pictures of a children's event in our Chapel. I have the standard EOS kit which means I have the 18-55mm lens and the built-in flash. I went in early to take some test shots and the Auto Everything shots looked bad in the lighting, I could not find an exposure and white balance that looked right, and using the flash made everyone's face look very white and washed out (told you I was a newbie).

I finally did a custom whte balance (without flash) and was able to get pretty even color across the pictures. They looked good on the LCD display. I took a bunch of pictures and when I got home to look at them in Photoshop, they looked a lot darker on the PC screen. I then applied the Photoshop CS Shadow/Highlight option and it created major moire patterns across the their clothes and background. I tried using a simple level adjustment to brighten them up, but they were still dark, so I had to use the levels and the hightlights (resulting in moire). Luckily, once I shrunk them down for the church's web site, they don't show the moire patterns.

With all this in mind ..... Here are my questions if you have the time:

1) What causes moire patterns and is there anything I can do to prevent it up front? The shots were taken with no flash using a custom white balance, an ISO of 1600 (I took some test shots at 800, but the movement of the kids caused a blur so I turned it to the highest setting allowed), f/4.5 and shutter speed set at 1/40 sec.

2) Is it normal for the picture to look brighter on the LCD that it acutally looks on the PC? If so, should I adjust on the camera until it looks brighter than needed?

3) Is it normal for the flash to casue the background to look good and the faces to looked white and washed out when the WB is set to indoor lights? Is that a camera setting I messed up (f/stop, shutter, etc.)?

4) Could the picture quality setting have anything to do with the above? I shot the pictures at JPG Large, but not at the "finest" setting.

Thanks again for your help! We are heading out of town in the morning for the Christmas holiday, and I plan to take a bunch of pictures on the trip. I hope to play with the camera some more this afternoon to try to answer some of these questions on my own, but packing the car will limit that time.

Earl