Pixels in terms of photo enlargements

[realworld]

I hope I'm phrasing my Question properly, but in terms of enlarging a photo- if your camera is 8.2 mp, generally how big can you go without the photo getting grainy? Does it depend on the camera or is there a more or less standard chart.

[mwfanelli]

I hope I'm phrasing my Question properly, but in terms of enlarging a photo- if your camera is 8.2 mp, generally how big can you go without the photo getting grainy? Does it depend on the camera or is there a more or less standard chart.

Unlike film, the digital image does not get grainy. It will start to exhibit blockiness and jagged edges.

The pixels you need depends upon the output device. High quality output usually wants 300 ppi. So, an 8x10 would need 2400 x 3000 pixels. A lower quality but still very acceptable can go down to 240 ppi.

You can also interpolate the image. This is a time-proven mathematical technique that adds pixels to the image. It works well as long as you don't overdo it.

In any case, your digital image will enlarge better than any 35mm film would.