We are going to make photorealistic push pin portraits.
We will be guided in our pin placement by a low resolution indexed color gif image we will create in Photoshop. The .gif will use a limited palette restricted only to those colors in which the plastic push pins come.
This tutorial assumes you have some access to and basic understanding of Adobe Photoshop.
Step 1: Select a photograph
Using Photoshop, adjust your image so that it contains a nice range of colors and values, with no large areas of pure black or white or any other color. This will give you a dappled variety of push pin colors across the finished artwork, rather than large, boring expanses of a single hue.
I'm using a photo I took of a woman who sells her hats and headdresses on the internet
Step 2: Decide the final dimensions of your work in inches
I'd like my final artwork to by 45" wide by 60" tall. My push pins are 0.5" in diameter, so I'll need to shrink my photo to 90 pixels x 120 pixels where each pixel will ultimately represent a push pin. That means I'll have 90 x 120 = 10,800 pins total.
Step 3: Convert the photo to a .gif of limited colors
First determine the colors you intend to use. I have chosen black, white, red, yellow, and blue, for a total of 5 colors. I have omitted green from my artwork, even though push pins often come in green Notice my photo contains regions that appear green. Those regions will appear green in the finished artwork as well, even without the use of green pins, thanks to the color mixing that occurs in a dithered .gif
Step 4: Count pixels of each color so you can buy pins accordingly
Your histogram can count the number of pixels selected.
Using your magic wand tool set to non-contiguous regions, tolerance = 0, visit your tiny 90 x 120 .gif and select each color in turn.
Record the count reported by the histogram for each color, That's ho wmany push pins of that color you'll need.