Graininess (with SD400)

[jlink7]

Over the 4th of July, myself and a buddy took a bunch of pictures. Me with my SD400, and him with another 5.0 mp. I'm somewhat disappointed with the results of the SD400's quality.
I'll let you see the difference, I think it's pretty obvious. (Warning though, these pictures are not for the thin-bandwidth user, they are large.)

His picture: http://fryfrog.com/gallery/4July2005/acr#
My picture: http://fryfrog.com/gallery/4July2005/aid#
Another of my pictures: http://fryfrog.com/gallery/4July2005/acw#

As you can see, the second one is a lot better than my first one. As I am new to digital photography, I believe for the first one was I was playing around with the custom setting, but I don't know what setting (I didn't use any of the color filter or light filter settings) may have caused it. Could it possibly be because of a different ISO or aperature timing setting (I think it ranges +/- 2). Anyway, just looking for a good way to get the best pictures.

The main thing I am looking for is to be able to take pictures of somewhat instantaneous occurances... for instance my neice jumping into the lake, etc. Right now, on auto, there is a significant delay before it actually snaps the pic unless I mess with the custom settings. Any advice would be appreciated!

[flak]

high ISO will increase the noise a lot, i don't know what ISO values you can set in the SD400, but always try to work @ the smallest possible ISO at all times, and only increase it when you have a tough underexposed shot, with aperture/shutter speeds locked

[JohnnyE]

After checking the EXIF data on the shots, the ISO was a big part of it. The SD400 image was shot at ISO400, while the other was at ISO64.

[tdaugharty]

Something I do not understand. If shotting at ISO 200 or higher why the noise? Will shooting RAW allow higher ISO speeds with moving subjects?

[KevC]

Something I do not understand. If shotting at ISO 200 or higher why the noise? Will shooting RAW allow higher ISO speeds with moving subjects?

ISO is light sensitivity. I don't know the physics of it, but it's an fact that the higher the ISO, the more noise the image will have. Shooting RAW or JPG wont really have an effect on how much noise there is in the image coming out of the camera, but shooting RAW gives you a more exposure lattitude and it's probably easier for the nosie cleaning software to deal with.

Higher ISO allows for slower shutter speeds (given everything else remains the same). Also shoot as low ISO as you can! But then, a noisy image is better than a blurry one (handheld camera shake). Keep an eye on your shutter speeds and you'll be fine.

[fryfrog]

In film cameras, when you buy your film you pick your ISO. So you can't really change ISO with out changing rolls of film. In a digital camera, all you have is the sensor. You can't change how sensitive to light it can be, it is always going to be the same. So the ISO settings on a digital camera determin how much the signal is amplified, to simulate ISO. The more you amplify the signal, the more noise you introduce *AND* amplifiy. At least, I think thats it.

I ended up at this thread because of my referer logs... jlink is that friend he was talking about! I also did some re-arranging in my gallery, so some of those links don't point to the right images anymore. I couldn't figure out what the differences were, I'm glad you guys noticed the huge differences in ISO, thanks :)