Canon EOS 700D (T5i) Producing 72 dpi images

cgarzi wrote:

Our Canon EOS 700D (T5i) camera has been producing images with a dpi of 72, when we obviously need 300 dpi for our print products.

We've read the user manual and played around with all the settings (and we have some experienced photographers in the office), and no one can figure it out. Can anyone provide some assistance? We do not want to shoot raw.

Thanks,

Caitlin

DPI is an often misunderstood subject. The short answer is that the dpi you find within the exif data of the jpg to be irrelevant. It is just a number for an application to use as a baseline to interpret the pixels at what physical dimensions it should be rendered.

The DPI doesn't change the fact that the 700D produces 18 MP images. The pixels aren't changed, the representation is changed. If 72dpi is set and you load it up in photoshop, it will happily print it way too large on your paper. If set to 300 dpi it might fit a 40x30 cm sheet of paper.

The 700D resolution is: 5184 x 2912 pixels.

DPI = inches / number of pixels

72 = inches / 5184

inches = 5184 / 72 = 72"

inches = 2912 / 72 = 40"

72" x 40". That's the physical size you'd need to print the image.

You do not need to shoot raw, merely to understand what dpi actually represents.

So if you set dpi to 300, the size will be

dpi = inches / pixels

300 = inches / 5184

inches = 5184 / 300 = 17"

inches = 2912 / 300 = 9"

The size you'll end up with physically is 17" x 9". If you print it smaller, all it will do is give you a smaller yet sharper image, the number of pixels will not change, it's still the same 5184 x 2912 pixel image.

It's like drawing a grid on a deflated balloon. Inflate the balloon the number of squares in the grid doesn't change, but the physical size of the grid will increase. The lines may become more blurry though.