Image Size & DPI

Comment on Photo Book Printing
Ruth
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Joined: 14 May 2011

Re: Image Size & DPI

Posted:03 Jun 2011 (16:51 UTC)
Greetings Ruth,

Thank you for your question!

Most image formats like JPEG and PNG simply have fixed resolution that is raw pixel dimensions, like 2550x3300. If you print those pixels in a defined area, say 8.5" x 11", you will see you now have 2550 pixels / 8.5" = 300 pixels per inch, or "ppi". Similarly, 3300 pixels / 11" = 300 ppi.
For modern digital printers, "pixels" and "dots" are equivalent.
Some formats, like TIFF and PDF have dimensions *and* resolution.

Browsing through your gallery most of your photos seem fine to go to print. Even if they come shy of 300 dpi. Once images get over 150, the printer does a great job quality. The visual difference between 250dpi and 300dpi for example is almost indistinguishable.

-PrestoPhoto Support
Ruth
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Joined: 14 May 2011

Image Size & DPI

Posted:03 Jun 2011 (15:29 UTC)
I have uploaded all my pictures into the photo project. They are low dpi but very large in size. I know you say that i should upload them as 300 dpi but the overall size of the images are 10-15mb so are very large.

Does your software shrink down the image, so will it appear higher dpi?