I love Photoshop. It's one of those rare applications that has captured the hearts and minds of professional designers, photographers and home users the world over. It's effect has been so pervasive that it has well and truly become embedded in everyday pop culture. The idea of altering a photo or digital image using Photoshop has entered our vocabulary to the extent the Oxford English Dictionary has added Photoshop as a verb: "alter (a photographic image) digitally using computer software:the pictures have obviously been photoshopped"!
One of the tools I like best in Photoshop is the gradient tool. Don't ask why, but let me loose in Photoshop and I'm bound to have used a gradient on at least one layer!! However, I never considered using the gradient tool as a means for color correcting an area of a photo... You can use gradients on separate layers to your main image, but let's take a look at how to achieve this directly on a photo itself (yes, it is a Photoshop faux pas, however, it does reduce the file size and processing time!) Read on to learn how to do this...
First, select the Gradient Tool from the Tool Palette. and in the Gradient Editor select the Foreground to Transparent gradient.
Choose your color. A nice touch in Photoshop CS5 is to select colors from the Open GL Color Picker. On a Mac hold down Control + Option + Command and click and on Windows: Shift + Alt + Right-click. This will enable you to pick a suitable color to use to brighten up an area in the photo.
In the problematic photo below, the top half of the picture is too dark and we can use the gradient tool to bring out the greens in that area.
Drag a gradient over the area of the image you wish to color correct. In the example below we dragged the gradient starting at the darkest point to the lightest area. The opacity for this gradient is 40%. However, if you want to change the opacity after applying a gradient, you might normally undo, change the opacity, re-draw the gradient, etc. It can lead to a lot of trial and error. There is another way though...
We can fade and blend the gradient after applying it to an image instead of redrawing with different opacity settings! Choose Edit > Fade Gradient...
From the Fade window you can try out different settings for both the opacity and blending modes before applying them.
Be sure to use the Preview checkbox to A-B changes and see the Fade results vs the original image. When you're happy with the results click OK.
For the picture above an opacity of 99 and blending mode of Soft Light brought out the greens in the top area. Be aware that there are other ways in Photoshop to achieve this. Some techniques will give better results than others - but this can be a particularly fast and acceptable method in many situations.
There are plenty more Photoshop tips and tricks. This particular tip is one of many from the Photoshop CS5 101 Core Photoshop CS5 tutorial by Jim Kanter. I'd highly recommend checking it out even if you are familiar with Photoshop!