Thursday, January 18, 2007
January/February 2006 HelpLine
Q) My second question is how do I fit an image to a standard-sized mat or frame? For example, a pixel size of 2048 x 3072 has a document size of 6.827x10.24 inches at 300 ppi. How do I print this 6.827x10.24-inch image so that it will fit into the opening of an 8x10-inch mat without cropping it, adding more canvas and cloning more background (thereby changing the composition), or distorting it by unchecking Constrain Proportions in Photoshop's Image Size dialog box?
A) Distorting the image isn't the answer, and cloning would be a lot of work, besides not matching the original scene. So that appears to leave cropping.
You first need to get an image that fills the mat size, then, as you'll see, you have to crop it because you're dealing with two different aspect ratios. First, let's look at getting the right size. Because you're changing the pixel count of your image to 300 ppi, the resulting size isn't quite large enough.
Go to the image-resize part of your image processor and be sure resampling of any kind isn't checked. You want to use your original pixels. Then adjust your dpi to 250. That should be enough resolution and will boost your image printing size to a width slightly larger than eight inches. The length won't yet be correct for the 8x10 size because it all comes down to aspect ratio-the ratio of width to height.
Digital SLRs' aspect ratio is based on 35mm. The actual image size of a 35mm frame is 36x24mm. That equals an image aspect ratio of 1.5:1, more commonly called 3:2. When camera manufacturers try to design a camera that feels like, works like and acts like a 35mm film camera, you can be fairly certain they want the image aspect ratio to measure up.
Let's take a look at an 8x10. This is a standard size based on formats used by photographers back in the 1800s. Rotating the dimensions so they read comparable to my 35mm calculations, you get 10x8, and dividing by two makes for a 5:4 aspect ratio. This isn't 3:2.
While some might attribute this "rectangular peg in a square hole" printing problem to digital cameras, those cameras are really acting just like a film camera. A full-frame print from 35mm equals not 8x10 inches, but rather 8x12 inches, which means it has to be cropped to fit an 8x10-inch mat, just like the digital image must be cropped. (Note that some non-SLR digital cameras shoot in different aspect ratios, like 4:3 or even 16:9.)
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