Pixels have to do with the picture size, not focus. So it depends on how big you want the photos to be. You can't enlarge them and keep them quality. But if you're only going to want them like 4 by 6, then you don't want to take HUGE photos as they will take up more room on your memory card. What size memory card do you have?
Mine is set to take them at 3264 x 2448 and then I resize most of them on my computer. I do this because then I can crop the photo if the horse isn't as "big" in the picture, and you'd never know. I can also print them large if I want. But they are HUUUUUGE at that size
Just some comparison...
Here is a photo at 640 by 480
Here is photo at 900 by 675 (if the photo appears small, click on it)
http://cheyautranch.deviantart.com/art/My-loves-96761034
And here I uploaded one at full size (the 3264 by 2448) for you to see (again, if the photo appears small, click on it)
http://cheyautranch.deviantart.com/art/Interest-97173304
I have a 4GB memory card, so I can take hundreds of photos at that size. Plus I have two back up cards (a 2GB and I forget the other... I hardly EVER use them). If you have a smaller card, you need to make your pixels set at a smaller size.
What makes a difference in clarity in light and speed are things like shutter speed, F number, focal lenght, ISO. I know nothing about those yet. My cam does manual or auto, and so far I've just used auto. So hopefully someone else can help you out there!
Jessi
