You will consider two steps once you have decided you want to use a picture: cropping and sizing.
Cropping determines content and shape. It's more art than math. You ask yourself these questions:
- What part of the picture do you want to use?
- What shape will that be?
Sizing determines reproduction (new) dimensions. It's more math than art. You ask these questions:
- How big would you like the picture to be?
- What are the original (old) dimensions?
- What will be the reproduction (new) dimensions?
- Do I need to recrop to make it fit better?
- Do I need to resize to keep the content and shape I want?
Cropping completes a process you started with the camera and enlarger: to decide the content of the picture. You do this by eliminating what you don't want either electronically, or by use of crop marks.
To use crop marks, make sure there are margins (white areas) around the outside of your photo. You will need space on at least one vertical side and one horizontal side to put your crop marks. If the photo itself does not have margins, mount it on something else. Use carefully drawn straight lines in the margins to show the left, right, top and bottom limits of what you want the cropped photo to have in it.
Sizing makes a photo fit where you want it to go on a page. You are PROPORTIONALLY changing the image you have created with your cropping. Start by measuring the cropped portion of the original photo. This gives you the original width and height ("Height" is sometimes called "depth," but we'll stick to "height.")
Now, on the page, measure one of the reproduction dimensions. Use the dimension that's least likely to change. Often that's the width because people stick to predetermined column widths. For now, do that, too. You will use these numbers to get both the: percentage of enlargement or reduction AND the length of the dimension that's missing, which is, in this case, the new height.
For the percentage of enlargement or reduction, create a fraction putting the new width over the old width.
New Width/Old Width = X%
X % will be:
- greater than 100 if you are enlarging the image.
- less than 100 if you are reducing the image.
This X value gives you the length of the missing dimension.
Multiply the dimension you know, in this case the OLD HEIGHT, by X. Old height times X = NEW HEIGHT.
To think about this visually, imagine a diagonal line that runs from the top left corner of the CROPPED area of your picture through the bottom right hand corner. When you stay in proportion, any point on that line represents a potential new height and width of your image.
Your reproduction dimensions may not fit the layout you had planned. When that happens, you have two choices:
- Change the layout.
- Change the crop.
When you change the original photo with new crop marks, you automatically change the reproduction. For example, if the new height was too tall, you can check the original photo to see if you can "crop" off some of the top or bottom. The same thing works with the width. The tricky part is figuring out how much is just right. There's no fast solution here. You just have to keep going back to the formula. New:Old = New:Old.
Adapted from training materials by Knight International Press Fellow, Herman Obermayer.