Photo_Sizes_AC4x6In previous lessons, I talked about photography close-ups and cropping. Today my lesson about actual photo sizes deals with the idea of photo sizes, how they impact a photo’s ratio, and how that ratio affects the rules of photography.

Let’s Get Started

Photographs come in various sizes. Some standard photo sizes (for Americans, at least) are:

    3×5 inches
    4×6 inches
    5×7 inches
    8×10 inches
    8×12 inches
    11×14 inches
    20×30 inches
    24×36 inches

Look at each of these sizes again. Notice anything odd? Many of the different sizes have different aspect ratios. This means that, depending on which size you wish your photo print to be, the comparative correlation between an image’s width and its height will change. This means, for example, that an image of a boy running after a bouncing ball may not show all of the boy and/or all of the ball depending on what size you print the photo.

In order to properly understand how the aspect ratios of photographs work, we need to do some simple math. Don’t worry, this won’t take long and it should be relatively pain-free. Let us look at the photo sizes again. This time, however, we are going to use whole numbers (1, 2, 3, 4, 5, 6, 7, 8, 9, 10…) to divide the width and height of each image size to its smallest whole number measurements. In other words, we are using fractions of the current sizes to find out their ratios.

3×5 inches: 3 cannot be divided by any whole number to make it a smaller whole number so it stays the same (3/3=1, 3/2=.6666, 3/1=3); 5 cannot be divided by any whole number to make it a smaller whole number so it stays the same. Therefore, the aspect ratio of a 3 inch by 5 inch photo is 3:5.

4×6 inches: 4 can be divided by 2 to equal 2 (4/2=2). 6 can also be divided by 2 to equal 3 (6/2=3). Therefore, the aspect ratio of a 4 inch by 6 inch photo is 2:3.

5×7 inches: 5 cannot be divided by any whole number to make it a smaller whole number so it stays the same; 7 cannot be divided by any whole number to make it a smaller whole number so it stays the same. Therefore, the aspect ratio of a 5 inch by 7 inch photo is 5:7.

8×10 inches: 8 can be divided by 2 to equal 4 (8/2=4). 10 can also be divided by 2 to equal 5 (10/2=5). Therefore, the aspect ratio of an 8 inch by 10 inch photo is 4:5.

8×12 inches: 8 can be divided by 4 to equal 2 (8/4=2). 12 can also be divided by 4 to equal 3 (12/4=3). Therefore, the aspect ratio of an 8 inch by 12 inch photo is 2:3.

11×14 inches: 11 cannot be divided by any whole number to make it a smaller whole number so it stays the same. Because 11 cannot be divided, we cannot divide 14 by any whole number to make it a smaller whole number either so it stays the same. Therefore, the aspect ratio of an 11 inch by 14 inch photo is 11:14.

20×30 inches: 20 can be divided by 10 to equal 2 (20/10=2). 30 can also be divided by 10 to equal 3 (30/10=3). Therefore, the aspect ratio of a 20 inch by 30 inch photo is 2:3.

24×36 inches: 24 can be divided by 12 to equal 2 (24/12=2). 36 can also be divided by 12 to equal 3 (36/12=3). Therefore, the aspect ratio of a 24 inch by 36 inch photo is 2:3.

Photograph print sizes directly affect the aspect ratio of photos and, therefore, change what rules of photography exist in a certain photo. After all, if you have a 5×7 inch print and a 4×6 inch print of the same photo image, the image will look different because different parts will be trimmed from the original image.

Most cameras (including my Canon camera) capture images in a 2×3 aspect ratio format. Consequently a photo using The Rule of Thirds or Leading Lines will look great as a 4×6 inch print or an 8×12 inch print, but terrible as a 3×5 inch or 8×10 inch print. Conversely, photos using the photography rules of focus/depth of field, color and contrast, or centering will likely look good using almost any print size because the different edge-cropping amounts will not adversely affect the look of the subject.

Let’s Break It Down

Leading Lines: (usually an aspect-ratio sensitive rule)

“Look-Out Mountain, Idaho”
The sky and part of the hills will be lost if this photo is printed as a 3×5 inch size, 5×7 inch size, 8×10 inch size, or any other size that does not have a 2:3 aspect ratio.

Flanking: (usually an aspect-ratio sensitive rule)

“Floating Between Paths”
The lines of road may not meet the photo’s corners if this photo is printed as a 3×5 inch size, 5×7 inch size, 8×10 inch size, or any other size that does not have a 2:3 aspect ratio.

Rule of Thirds and Balance: (usually aspect-ratio sensitive rules)

“In Wonder”
Essential parts of the sky and land will be lost and the balloon will not appear near the upper right axis of the image if this photo is printed as a 3×5 inch size, 5×7 inch size, 8×10 inch size, or any other size that does not have a 2:3 aspect ratio.

“Blue Undulations”
Essential parts of the sky, land, and water ripples will be lost in the image if this photo is printed as a 3×5 inch size, 5×7 inch size, 8×10 inch size, or any other size that does not have a 2:3 aspect ratio.

Focus/Depth of Field: (can be EITHER an aspect-ratio sensitive rule or not depending on the main subject’s location within the image)

“Budding Serenity”
Nonessential parts of the out-of-focus lily pads, but none of the lotus bud main subject will be lost in the image if this photo is printed as a 3×5 inch size, 5×7 inch size, 8×10 inch size, or any other size that does not have a 2:3 aspect ratio.

Centering: (usually NOT an aspect-ratio sensitive rule)

“The Lord God Loves Them All”
Nonessential parts of the background and hands, but none of the butterfly main subject will be lost in the image if this photo is printed as a 3×5 inch size, 5×7 inch size, 8×10 inch size, or any other size that does not have a 2:3 aspect ratio.

Color and Contrast: (can be EITHER an aspect-ratio sensitive rule or not depending on the main subject’s location within the image)

“Contrast”
Nonessential parts of the purple prickly pear pads, but none of the flower main subject will be lost in the image if this photo is printed as a 3×5 inch size, 5×7 inch size, 8×10 inch size, or any other size that does not have a 2:3 aspect ratio.

Framing: (can be EITHER an aspect-ratio sensitive rule or not depending on the main subject’s location within the image)

“Colorful Perspective”
Nonessential parts of the hot air balloon envelope, but none of its center or the framed pilot will be lost in the image if this photo is printed as a 3×5 inch size, 5×7 inch size, 8×10 inch size, or any other size that does not have a 2:3 aspect ratio.

Close Ups: (can be EITHER an aspect-ratio sensitive rule or not)

“Aqua Dust”
Essential parts of the bottle will be lost in the image if this photo is printed as a 3×5 inch size, 5×7 inch size, 8×10 inch size, or any other size that does not have a 2:3 aspect ratio.

“Vibrant”
Nonessential parts of the lotus flower will be lost in the image if this photo is printed as a 3×5 inch size, 5×7 inch size, 8×10 inch size, or any other size that does not have a 2:3 aspect ratio.

Cropping: (can be EITHER an aspect-ratio sensitive rule or not)

“Egret Alphabet”
Essential parts of the bird will be lost in the image if this photo is printed as a 3×5 inch size, 5×7 inch size, 8×10 inch size, or any other size that does not have a 2:3 aspect ratio.

“Iron Mantis”
Essential parts of the insect sculpture will be lost in the image if this photo is printed as a 3×5 inch size, 5×7 inch size, 8×10 inch size, or any other size that does not have a 2:3 aspect ratio.

Photographer’s Note

I did not mention two photo sizes of squares and wallets above because they can be controversial. Squares have a 1:1 ratio. Wallets are often sized at 2×3 inches or 2.25X3.25 inches. Remember that the printers you use will what size formats you can choose. Keep these points in mind as you begin your homework. Please refer back to my lessons on the various rules of photography if you need help.

Homework

Shoot 20 images or more using the different rules of photography. Half of these should use photography rules such as Leading Lines, Rule of Thirds, and Flanking that cannot be easily printed in anything other than the camera’s original shooting ratio while the other half should use rules like Centering, Depth of Field, Framing, and Color Contrast that are more flexible when working with print size. As always I ask that you look for unique angles to use when shooting your subjects and have fun!

Until we meet again, I wish all of you brilliant flashes of perspective!

[ O*] Alycia