Workshop

Q&A

Q3:

Q1:	Levels and Curves seem to do more or less the same thing. How do I know which to use?
A1:	If the picture seems to have the right color balance (not too red, green, and so on) but is too dark or light, use Levels. If the colors aren't right, adjust the Curves for individual colors and for the RGB (full-spectrum) channel.
Q2:	I have a sepia- tinted photo (brown tones) that I have scanned into the computer, but the scan came out yellow. Is there a way to get rid of the yellow cast without losing the sepia?
A2:	The easy way is to convert it to grayscale so that you get rid of all the color. Then convert the image back to RGB. Open the Image Adjustments Curves dialog box. Instead of RGB on the Channels pop-up menu, select red and drag the curve up until you have added an appropriate amount of red. Then set the pop-up menu to green and drag the curve up until you have added enough of that color. Finally, set the pop-up menu to blue and drag down until you have removed the blue and achieved a reasonable amount of sepia. Experiment until you get the color you want, and then click OK.
If the picture's going to be printed in black-and-white for a newsletter, do I really need to adjust the color balance and stuff?
A3:	Always leave your options open. Adjust a copy of the picture in Grayscale mode, just to make sure that the contrast is good for reproduction. For that, you don't need to think about color. But keep a copy in color in case you want to put the same picture on a web page or do something else with it later.

Quiz

1:	A picture came out too green. What should you do? Open Variations and choose more red. Open Variations and choose more magenta . Say you took it in Ireland.
2:	A picture was taken on a foggy day, and its colors look washed out. Is there any way to fix it? Increase the saturation. Lower the lightness. Paint over the picture with brighter colors.
3:	How can you lessen the amount of change in the Variations dialog box? Hold Shift+Control+P while you click the thumbnail. Use the Fine/Coarse slider. You can't.

Quiz Answers

A1:	b. On the color wheel, magenta is opposite green, so adding more magenta removes excess green.
A2:	a. Weak colors lack saturation. Increasing saturation slightly brightens the picture, but don't overdo!
A3:	b. Moving the slider toward Fine lessens the amount of correction applied each time. (Trying to implement answer a. would probably sprain a finger.)

Exercise

Download some of the photos from the Sams website. To get to the website, point your web browser to http://www.samspublishing.com/. In the Search box, type Photoshop in 24 . Find this book in the list that appears, and click the link. On the book's main page, find and click the Related Materials link to get to the files. Then see how much further you can go. Turn a cloudy day into a sunny one and vice versa. Experiment. Try your hand at changing the colors by eye, and then see whether you can duplicate your efforts by using the histograms.