Dpi

NoCountMule

Would someone please enlighten me on something ? I've been asked to photograph some landscape shots for advertising purposes. I was told to make sure they are at least 300 dpi so they'll be printabable. Now I know when I download my pis to my computor the're 72 dpi.Question is , Can I make these changes or is this something that is changed by the printing service ?
I really need help here in a bad way.

Thanks to you in advance.

pathfinder

DPI or dots per inch is a printer specification describing how many dots of ink per inch a printer puts to paper, and has nothing to do with image file quality. Period. You can, theoretically, print a one pixel image on an inkjet that prints 2400 dpi.

Pixels per inch - ppi - is the correct term for image file quality.

What you are really concerned with is your total number of pixels along the long and short margins of your image, such that divided by 300, you will have enough pixels for 300 ppi at the image size you want your print.

So, how large an image are you or your client wanting to print, and is your file large enough in total pixels for the specified size at 300 ppi?

Many cameras output files as 72 pixels per inch, but image files have no size specification, only a number of pixels.

If your file is not large enough at 300ppi, then you may have to uprez your image in Photoshop or Genuine Fractals.

I wrote about image resolution and uprezzing here - http://pathfinder.smugmug.com/Other/Resolution-Resizing-and-Dots/2246604_CgPjC