does anyone know how to change the dpi i always thought it was the same as pixels/in however someone told me today that was different.
If the file is already open, you go to Image>> Image Size. Or you can use shortcut "Alt+Ctrl+I". In the image size windows, look at Document Size: There is a textbox with the name Resolution. That is where you change the dpi in Photoshop.
Also, if you want to keep the same pixels size, you should uncheck "Resample Image" from "Image Size" window.
Pixels per inch means nothing until you print the image, or are getting ready to. I've got a pair of 22" screens at work, a 17" in my laptop, and plenty of people are stuck at 14" lappies. The name number of pixels will be displayed over a different area ( ie number of inches ).