Gradient Maps - MsZentech · Experiment with Gradient Maps and Blend modes on color images to mimic Instagram filters Try layering Gradient Maps for more complex effects Use a Gradient

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Gradient Maps

What You’ll Need:● A black and white image, converted to grayscale (we created this one with Adobe Fresco)● Adobe Photoshop Creative Cloud

How Long Will It Take?This project can take anywhere from 30-90 minutes, depending on the level of depth you want to approach the subject. We take 60 minutes to compose the image, then approximately 30 minutes to play in Photoshop.

ADOBE PHOTOSHOP ADVANCED

A LESSON ABOUT TONAL VALUES

A histogram displays the tonal range (or key type) of an image; it shows how the pixels are distributed by graphing the number of pixels at each of the 256 brightness levels in an image. As a photography teacher, I found that my student had a difficult time understanding this concept, until they began to play with the gradient map tool. This visual method created a link from the graph to pixel distribution that made a histogram come to life in full color!





Step #1 - Create/Prep the Image

This project works with photos or art; we created our images using the Adobe Fresco app. It allowed students to create on their own time, using their own mobile devices. Some students opted for a photography composition instead; either will work.

When I first introduce the Histogram, it’s easier for the students to understand it with less data; that’s why we convert the image to grayscale. We will convert it back when we are ready to apply the map.

● Open the image in Photoshop● Go to Image>Mode>Grayscale

Hint: Converting to grayscale is a horrible way to make a black & white composition; the Black & White adjustment filter is a much better option. However, in this project, we want to simplify the Histogram, so we’ll make an exception.

Step #2 - Open the Histogram

The histogram is a powerful tool, and most DSLR cameras provide one in their display They can help students compose better compositions, as well as prepare images for printing without “blown-out” highlights and shadows without detail.

Go to Window>Histogram

Histograms are like fingerprints; every image has a unique one. Students need to recognize that they will vary wildly; what is important is that understand how to read it, and what it means.

High key photography has a lot of white pixels; you can see that in the example to the left.

Conversely, low-key photography has a lot of dark pixels, so the histogram is higher where the black pixels live.

Number of black pixels in the

image

Number of white pixels in the

image

Shades of gray pixels





Step #3 - Convert to RGB

Converting the image to RGB allows us to add color to it. You may wonder why I had students convert it in the first place; this step introduces them to various color models, which you can use as an opportunity to either elaborate or ignore. I try to bring up color modes whenever I can so students understand how they differ.

Go to Image>Mode>RGB

Step #4 - Add a Gradient Map Adjustment Layer

There are four ways to create a gradient map, and two of them are destructive, so we will not be using those options. To create a nondestructive adjustment layer,

● Go to Layer>New Adjustment Layer>Gradient Map, or

● Click on the Adjustment Layer icon on the bottom of your Layers palette and choose Gradient Map.

Depending on your version of Photoshop, a dialog box or a Properties palette will appear for you to adjust the settings.

A gradient map looks at your histogram, and replaces the black, white, and shades of gray with colors that you designate within the gradient.

Looking at the example to the right, you can see Photoshop has replaced our black pixels with the purple, and our white pixels are now replaced with pink.

Because you can customize your gradient, this can be a powerful creative tool. Check out gradient basics on the next page to see how to alter them.





The Gradient EditorOften overlooked, the Gradient Editor is a powerful tool that can be used for both correction and creative projects. You can use it to build sunsets, sunrises, and beautiful blue skies, or you can create a set of gradient maps to quickly recolor your image, fake a filter effect, or create stunning contrast in boring photos.

Presets are the standard gradients that come with

Photoshop.

Folders house gradient collections. You can import .grd

files with new gradient sets

If you create a custom gradient, you can name it here. Solid gradients are used most

common, but Noise gradients are often used to create special effects

The tiny little squares are called “stops.”

The stops on the top side of the gradient denote transparency.

White is “clear,” while a black stop means the color is 100% opaque.

You can create interesting overlays by experimenting with

transparency.

The stops on the bottom side of the gradient control

color.

You can add additional color stops simply by

clicking on the bottom side of the gradient.

This setting allows you to change the color of a stop; click

on the stop, then adjust the color here.

Adjusts the location of the color stop. You can also simply

slide the stop along the gradient to adjust it.

The diamond sliders allow you to control how quickly the midtones blend between

colors.

You can use these commands to import gradient sets from an external file, or save a set of gradients that

you’ve created by exporting.

To remove a color from your gradient, click on the stop and press delete. You can also hit

delete on your keyboard.





Take it to the Next Level!

● Experiment with Gradient Maps and Blend modes on color images to mimic Instagram filters

● Try layering Gradient Maps for more complex effects

● Use a Gradient Map to take color out of an image, and adjust the gradient to get more contrast

Step #5 - Adjust the gradient

This is where students can really start to experiment. Adding more colors to the gradient pushes color into the midtones.

Try putting light colors on the left of the gradient and darker colors on the right for a negative effect.

Changing the Blending mode in the Layers palette creates an additional set of effects; challenge students to come up with their own set of “filters!”

Documents

Gradient Maps - MsZentech · Experiment with Gradient Maps and Blend modes on color images to mimic Instagram filters Try layering Gradient Maps for more complex effects Use a Gradient