Can someone who knows about graphic design please explain to me why when you change the size of a document...?

Question

and constrain the properties...an 8 x 10 is not the equivalent to a 5 x 7 and so on. I really suck at understanding numbers, so if you are explaining it....go slow.

Answer 1

If you have an 8"X10" document and try to shrink it to fit a 5"X7", it will not fit perfectly because these measurements are not multiples of one another. If you constrain a document's proportions, the image will not be distorted if you change a documents size. If you unconstrained the document, you can make it fit into whatever size you want, but there will be some stretching or distortion.

I hope this helps.

Answer 2

Because the aspect ratios are not the same.

If you have an 8 x 10, it has a 4 to 5 aspect ratio. That is, for every 8 inches of width, it has 10 inches of height (or vice-versa), which is the same as for every 4 inches of width, having 5 inches of height (or vice-versa).

Thus, if you scale an 8 x 10 to half-size, or 50%, it will measure 4 x 5.

A 5 x 7 has an aspect ratio of 5 to 7; that is, every 5 inches of width, it has 7 inches of height (or vice-versa). You'll notice that's not the same as 4 to 5.

So, if you try to reduce a 8 x 10 to a 5 x 7, and you don't constrain the height and width to match in terms of total reduction, either you wind up scrunching in the 8 inch side or stretching out the 10-inch side.

Why is that?

Because if I reduce the 10-inch side to fit in the 7-inch space, I am reducing the size of the image by 70 percent (7 / 10 * 100).

70 percent of 8 inches is 5.6; that's more than 5, so if I scale the image by the same amount in terms of height and width, I will lose some of the 8-inch side; if I just try to jam it in the space available, I have to scrunch in .6 inches of image.

If I reduce the 8-inch side to fit in the 5-inch space, I am reducing the image to 62.5 percent of its original size (5 / 8 * 100). That means the 10-inch side will be 6.25 inches long -- well short of 7 inches. So, for it to fit, I would have to stretch out the 10-inch side.

You can do this visually very easily.

1. Get a piece of 8 x 10 photo paper and a piece of 5 x 7 photo paper. Or, cut two normal sheets of writing paper to those dimensions.

2. Fold the 8 x 10 paper in half along its 10-inch side, so it measures 8 x 5. Unfold it.

3. Fold the 8 x 10 paper in half along the 4-inch side, so it measures 4 x 10. Unfold it.

4. You will now see the paper is creased into fourths. Cut one of those four squares, marked by the fold, out.

5. Measure the square you cut out. It will be 4 inches by 5 inches. That's a 4 to 5 aspect ratio.

6. Place the square you just cut out on top of the 5 x 7 paper. You will see it is smaller than the 5 x 7 paper.

Answer 3

I'll assume your using Photoshop and attempting to resize an image. Your problem is one of aspect ratio. That is the width of the image divided by the height. Using your example above an 8x10 image has an aspect ratio of 0.8. That's 8 divided by 10. The 5x7 image has an aspect ratio 0.71.

What this means is that if you want to change the exact image from an 8x10 to a 5x7 you will have to stretch, squish, or crop the image.

An easy way to get around this in Photoshop (and other image editors) is to use the square selection tool and changed it from freeform to fixed aspect ratio. If you set the width and height to 5 x 7 and then draw a box you can copy this selection in to a new image. You will lose some of your image, but it will not need to stretch or squish.

If you really must keep the entire image then an alternate method is to take the one side you must keep say the 5" and divide it by the other images aspect ratio. For instance the 8 by 10 you do the math and divide 8 by 10 and find 0.8. Then you take the 5 and divide by 0.8 giving you 6.25, so your new image would be 5 x 6.25.

It's unfortunate but you can't get an image from one aspect to another without some kind of stretch, squish, or crop.

Answer 4

It honestly has nothing to do with graphic design, this is all about proportions. I'm really not sure how I can explain this simply.
Maybe an example on how to figure it out would help.

If your original is 8" (width) x 10" (height) and you need the new image to have an width of 5", but you don't know what the new height will be. You can figure it out like this.

(Use cross multiplication for the first step to get 8x = 50)
(8/10) * (5/x)
8x = 50
x = 50/8
x = 6.25

So the new image would be 5" (wide) x 6.25" (height).

Answer 5

um that's basic math. ratios.
5/7
isn't equal
to
8/10