Tutorial 3 : No Highlight? Use Thresholds

No Highlight? Use Thresholds

The vertical dotted lines on the right and left are used to set the shadow and highlight points.

The "spotlighted" area has had its shadow point set in the usual way, and highlight set by dragging the dotted vertical threshold line, as shown the curve on the left.

Although you may simply read this tutorial, your time will be better spent if you copy the original image to your hard drive, and follow the example in Photoshop. This goes for all of the examples.

If you wish to follow along with this example, do a right click here, and select the option to save the target to your hard drive. Then start Photoshop, and open the image.

Click on the image to the right for more detailed instructions.

To start Curvemeister Curves from within Photoshop, select the Filter menu, move the mouse down to Curvemeister, and click on Curves.

Click on the Lab radio button, and then click on the Lightness Tab.

Now we're ready to go. Move the mouse over the edge of the graph area with the black border, until the mouse turns into a cursor, as shown in the illustration. The cursor is indicating that you may begin a threshold operation.

Note: If the special cursor does not appear, go back and check step 3.

Begin the threshold drag operation by clicking and holding the left mouse button, then moving the mouse toward the middle of the graph. We have begin the drag operation, and the image is being displayed in threshold mode, highlighting the areas that will be pure black in the final image.

The trick here is to not overdo it. Normally you would move the threshold line until you just begin to see black pixels appearing in the darkest areas of the image for which you wish to retain detail. In this case, the dark square of color in the bottom right corner of the balloon is just beginning to take on a pure black hue.

Congratulations - you are halfway there!.

The white point is set in much the same way as the black point. Grab the threshold line at the other end of the graph, and drag it toward the center until you just begin to see pure white pixels in the area of the image you care about.

Normally you would avoid creating large areas of pure white. In this case the white is just beginning to creep into the brightest areas of the seam of the balloon.

Press the compare button. There's more that can be done for this image, as you will see in later examples. For now, sit back and admire your work, confident that you have completed the most crucial step in improving your image. Drab images such as the one we started out with in step 1 are now a thing of the past.