Has this ever happened to you? You bring your digital images to the print lab and ask for 5 x 7 prints and when you compare them to you original photo files, you have parts cropped out? Now why is that? Did the lab screw up?
Basically, the aspect ratio of your original image isn’t the same as the aspect ratio of the print. Ok, before I go any further, let me explain “aspect ratio”. Aspect ratio is a measurement of the proportion of your image. The largest side divided by the smallest side of your image will give you your aspect ratio. For example, my D300 images are 4288 x 2848 which is an aspect ratio of 1.5:1 (my long side is 1.5 times longer than my short side). Of course, we humans don’t like decimals so we multiply the aspect ratio until we get full numbers. So my 1.5:1 ratio will become 3:2. Personally, I prefer seeing all my aspect ratios on a :1 base but that’s just me. 🙂
Let’s look at the standard print sizes and their aspect ratios. I’ve put the :1 ratio in brackets.
– 4 x 6 = 3:2 (1.5:1)
– 5 x 7 = 7:5 (1.4:1)
– 8 x 10 = 5:4 (1.25:1)
You can view a complete ratio table over at DPC Prints.
Now you can see if your original image has an aspect ratio of 3:2 and you asked for a 5 x 7, that part of your image will be cropped out at the lab; even worse if you get an 8 x 10. Here’s and example.
Now that you understand aspect ratio, you can now prepare your images accordingly in Photoshop so that you have total control of where the image is cropped. Video time! 🙂