pixel?

[jenlight81]

i have seen posts about using pixels for certain sized photos...is this something i can change...i am confused!!

[OsmosisStudios]

There's a general rule about a minimum amount of pixels being recommended for a particular print size. For BEST quality, we usually recommend 300PPI, which is to say 300 pixels for every inch of print. So, if you're making an 8x10, you need 2400x3000 pixels (about 10mp)

keep in mind, though, that this is a recommendation. I've printed shots at 24x36 inches with an image having 2400x3600 pixels: that's only 100PPI.

Unfortunately this isnt something you can realistically change. Your camera records images at a certain resolution (pixel x pixel). You can "UpSample", but that usually drops quality considerably. For just any size you could want, 10-12mp is fine, as long as your photo is properly exposed, technically sound and well processed.

[Xposurepro]

Don't simply rely on the number pixels when printing. Your camera grade also plays a big factor. For example, take an older pro level 3MP DSLR and compare it to a newer 10MP consumer level DSLR and the 3MP can either produce equal quality or out perform the 10MP DSLR.

[nokiN]

Originally Posted by jenlight81

i have seen posts about using pixels for certain sized photos...is this something i can change...i am confused!!

Yes, it's something you can change.

Most image editing software can be used to resize an image.

One of the considerations to resizing an image is the aspect ratio of the image. Most DSLR cameras make images in a 3:2 aspect ratio. An image that is 4 inches by inches is in a 3:2 aspect ratio. The long side is 3 units long (in this case each unit is 2 inches: 3 times 2 inches = 6 inches) and the short side is 2 units long (2 times 2 inches = 4 inches). Other sizes that are also 3:2 are:

• 6x9
  8x12
  10x15
  12x18
  16x24
  20x30

A popular aspect ratio is 5:4 or 8x10. If an image was made in a 3:2 aspect ratio, it has to be cropped to fit the 5:4 aspect ratio, it can't just be resized, because that would distort the image.

Now, back to pixel size. OsmosisStudios talked about ppi or pixels-per-inch. PPI has no effect until an image is going to be printed. For online or computer screen viewing ppi is meaningless and has no effect.

Back to our 4 inch by 6 inch image. If you want a high quality (300 ppi) 4x6 inch print, the pixel size of the image has to be 4x300ppi = 1200 pixels by 6x300ppi = 1800 pixels. You could also have a 4x6 inch print that is made at 100 ppi and tou would only need pixel dimensions of 4x100ppi = 400 pixels by 6x100ppi = 600 pixels. Both are 4x6 inches but have different pixel dimensions. They also have different visual quality.

It may be difficult to see much of a difference, in a 4x6, between 300ppi and 100 ppi. One of the top consumer labs in the country Mpix.com - Home bets their reputation on allowing 100 ppi as the minimum ppi they will print any of the print sizes they offer (24x36 is the largest).

Now for the next step. Let's go back to that 4x6 that was printed at 300 ppi. It has pixel dimensions of 1200 x 1800 pixels. That same image, printed at 100 ppi will be 12 inches x 18 inches. Do you follow the math? At 200 ppi the same 1200x1800 pixel image will print at 6x9.

Hopefully that helps you understand how pixel dimensions relates to ppi. Just a quick note. Though they are notthe same thing, the term dpi (dots-per-inch) is often used interchangeably with ppi.