I'm a bit confused as to how to calculate image size and resolution for printing an image. Say I want to print out an image to a 14x10 inch size, with at home or a lab. What should the image size be? I usually shoot in RAW and then export to jpg, but I can't figure out what size/resolution the jpg should be or if it should be a jpg at all. Any help is greatly appreciated.
It can be a High Quality JPG to be printed... Like JPG Quality at least 8, better 9, in a 1 to 10 range.
TIF files are fine too, but it is much larger on the internet, and not all print labs accept TIF. Nothing wrong with High Quality JPG for printing.
The normal and ideal printing resolution is 300 dpi (pixels per inch). Some people say ppi, and some say dpi. I'm an oldtimer, I say dpi.
Same thing in this context.
Whatever your inches, you need about 300 pixels per inch for that dimension.
This means to print 14x10 inches, you need to provide about
(14 inches x 300 dpi) x (10 inches x 300 dpi) = 4200 x 3000 pixels.
It need not be exact, but roughly this ballpark, within + or - 15% or 20% perhaps.
If you don't have that many pixels, fewer will work, but hopefully up near 200 pixels per inch. Many commercial print labs print 250 dpi anyway.
Image and paper SHAPE confuses many. For a silly but obvious example, if your image was rectangular but the paper was circular, the shapes simply don't match. Same for paper, some sizes like 6x4 inch prints are long and skinny, where 8x10 is shorter and wider.. Different shapes. Your image shape needs to match your paper shape.
Note that your uncropped DSLR image is the
SHAPE 3:2, which would scale to 15x10 inches, so you will have to crop the ends slightly to match the 14x10 paper shape. If you don't crop it first, the paper shape will crop it, but if you do it first, you get to see and approve the right crop first, so you know what is going to happen.
More about this sizing concept at
Image Resize - Cropping, Resampling, Scaling
I am being brief, hoping the link is "how to" ,but I am very happy to answer any questions.