Canon Powershot SD870 IS

I just purchased a SD870 IS and I had a couple of questions. When I take a picture with the flash on the foreground is always lit but the background is darkened to almost black. Why is that?

I also noticed that a lot of my pictures are grainy. I've tried playing with the settings but nothing seems to work for me. I'll try to take pictures of my children as they run about (they're restless and don't like their pictures taken) but they come out either blurry or grainy.

Can someone help me out? My previous camera was a Sony Cybershot W50 and when comparing the pictures, the Cybershot was slightly ahead.

The simple explanation for the black background - the flash isn't big enough to light up the background and the subject.

The technical explanation: light (including that from a flash) falls off as the square of the distance. So something 2 ft away from your flash gets 1/4 the light as something 1 ft. away. And something 3 ft. away gets 1/9 the light.

The "Grain" you're seeing is actually sensor noise, and occurs most commonly at high ISO settings (high amplification of the sensor signal) and with small sensor elements. High ISO settings are necessary to stop action in low light; high pixel-count sensors mean small sensor elements. Put them together and, voila, noise. The secret is, unless you're making really big (over 8x10) prints, you don't need the megapixels being crammed into today's cameras. So, shoot at the camera's maximum resolution, but use your computer to merge the pixels before making those small prints you hand out to everyone. The other secret is, when you print even at max. resolution the noise won't be quite so obvious.

I see. So before printing out my 4x3 prints merge the pixels... I usually use Photoshop to adjust the size of the images before I upload them to my photo album. The thing is my ISO setting is at either 100 or 200 most of the time. What do you mean by merging the pixels?

Hhhmmm, light foreground with a dark background with flash pics....NEVEC comes to mind and it's a normal function of the camera....

squ34k wrote in post #5409954
I see. So before printing out my 4x3 prints merge the pixels... I usually use Photoshop to adjust the size of the images before I upload them to my photo album. The thing is my ISO setting is at either 100 or 200 most of the time. What do you mean by merging the pixels?

Basically, resize the image from its 3264x2448 to, say, 1632x1224. You'll have enough data there for a 4x6 easily and will be able to get a decent 5x7 out of it. But because you've essentially used 4 pixels of the original picture to get one in the final one, you'll have averaged out a lot of the noise.