Web DevCenter
oreilly.comSafari Books Online.Conferences.
MySQL Conference and Expo April 14-17, 2008, Santa Clara, CA

Sponsored Developer Resources

Web Columns
Adobe GoLive
Essential JavaScript

Web Topics
All Articles
Scripting Languages

Atom 1.0 Feed RSS 1.0 Feed RSS 2.0 Feed

Learning Lab

The Ideal Digital Photographer's Workflow, Part 2

Steps for Editing Nondestructively on Your Images

by Ken Milburn, author of the upcoming Digital Photography: Expert Techniques

This article follows up on suggestions I made in Part 1 about creating a minimally destructive workflow for the work you do inside image-editing software, whether you're using Adobe Photoshop, PaintShop Pro, ULead PhotoImpact, Microsoft PictureIt!, or another editing program. Today we'll first look at five nondestructive editing steps you should take once you've downloaded your images. Then we'll examine some second-stage editing techniques designed to enhance the impact your images will have on your clients, or your friends and family.

Preparatory Steps

The first thing you should do after downloading images from your camera is to make it easy to choose exactly which pictures you want to keep. If you're a pro, you also want to spend the least amount of time needed to make the photos impressive enough to show the client.

Delete the Baddies

I suggest you start deleting the photos you don't want using your thumbnail image management program. For Windows folk, I recommend Adobe Photoshop Album; it's the most versatile of the under-$50 variety of these. (Corporate users and those who store their images on multiple servers or across a network may prefer Canto Cumulus or Extensis Portfolio. Mac users will benefit from the astounding speed and new features in iPhoto '04.)

To delete the baddies, highlight them in Album (or iPhoto, if you're a Mac user) and press the Delete/Backspace key. A dialog will ask if you're sure you want to delete the images. If the answer is yes, either click OK or press Return/Enter. Another dialog will appear to ask if you also want to delete the image from the hard drive.

Note: When low light forces slow shutter speeds, many photographers shoot several frames so that they can use their computer to choose the image with the least motion blur. If you have done this, the first images you should eliminate should be duplicates that are less sharp than the sharpest acceptable photo in the series. You'll automatically save a lot of disk space, eliminate the chances that you'll accidentally use a blurred image later, and make it easier to subjectively choose the other images you want to delete because you won't have as many images to look through.

Rotate the Verticals

Immediately after deleting the baddies (the more images you have to rotate, the longer it takes), select all the images that need to be vertically oriented and rotate them. If some need to be rotated left and others need to be rotated right, you will have to repeat the operation for each of those orientations. In order to minimize image deterioration, particularly if you plan to keep files stored as lossy JPEGs, it is best to rotate images to the correct orientation as soon as they are downloaded.

Match the Exposure and Contrast of Sequence Shots

If there are groups of pictures that have been taken of the same scene and that also use the same camera angle and lighting conditions, make sure that they are all of uniform brightness, contrast, and color balance. I always do this from within Photoshop Album because the edited version is saved without overwriting the original and that's what you see when Album displays the thumbnails. The fastest way to do this is with the AutoFix command, which makes a "best guess" for the correction of brightness, contrast, and color at the same time. AutoFix is the fast way to do it because it can be applied to any number of images that have been pre-selected in Album. Also, you don't have to switch to another application to do the processing. That is not to say that AutoFix will seem particularly fast, because waiting while doing nothing always seems to take forever. A gigabyte or two of RAM and a 2+ gigahertz processor will certainly help.

A better, but more time-consuming, alternative is to use Album/iPhoto to open the series of images in Photoshop (Elements or CS, no matter). The images will open in a stack. In the Layers palette, create an Adjustment Layer for Levels. Use the Levels dialog to set the absolute white and black point for the image (see Figure 1). Then drag the mid-tone slider to set the image brightness and click OK. Drag this first image to one side, open the Layers palette, and drag the Adjustment layer you created to each of the other images in turn. The same adjustments will then be made for each of those images. Once you've adjusted all the images, close each file. Album will add "edited" to the saved file's name so that it doesn't overwrite the original, then display only the new version.

Figure 1: The Levels dialog as it should look after maximizing the brightness/contrast range that can be shown in a photo.

If you're not happy with the result from Album's Quick Fixes, Photoshop and Photoshop Elements also offer numerous "one- (or two- or three-) click" automatic correction features as well. So if you have a series of pictures shot of the same subject under the same lighting conditions, you can select several by Cmd/Ctrl + clicking their thumbnails and then right-clicking to choose Edit in (Photoshop or Photoshop Elements) from the in- context menu.

Of course, some images simply need to be manually corrected if you want to be exacting as to how you, personally, want to control color and contrast. Starting in Album, so that your changes automatically stay organized in Album, highlight an individual thumbnail and then choose the Edit In command as described in the previous paragraph.

Here's the best routine for insuring that you are displaying the most complete tonal range that your sensor and exposure can provide. It's a good idea to run this routine on a duplicate of each image you shot:

  • In Photoshop or Adobe Photoshop Elements, choose the Levels command (Cmd/Ctrl + L). The Levels dialog, shown above in Figure 1, appears. In the center of the dialog is a histogram that looks like the drawing of a mountain. Beneath the histogram are three sliding pointers. The leftmost (Shadow) slider will indicate the point at which all pixels become absolute black. The rightmost (Highlight) slider indicates the point at which all pixels become absolute white. The center (Mid-tone) slider indicates the 50 percent gray point of brightness in the image. The histogram itself diagrams the number of pixels present at each level of gray between black and white.

    Note: Do NOT touch the Mid-tone (center) histogram slider until after all the highlight and shadow sliders have been adjusted for each color.
  • Adjust the histogram for each of the image's primary colors so that the shadow pointer is at the leftmost point at which the histogram starts to rise above ground level. If the histogram is already above ground level at the left margin, simply make sure the pointer has been moved all the way to the left.
  • Repeat the step above for the Highlight pointer, making sure that the pointer aligns with the first place the histograms starts to rise.
  • Repeat steps 2 and 3 (above) for each of the other primary colors.
  • Now go to the composite (RGB) histogram and, if necessary, repeat steps 2 and 3 for the composite image.
  • Now, while you are still in the RGB histogram, adjust the mid-tone slider until the image is as bright as you want it to be.
  • Now you can tweak the color balance by adjusting the mid-tone slider in one or more of the primary color histograms. I find this easiest if I look for a color that is too predominant and then subtract it. For instance, rainy day photos are usually a bit too blue. So I go to the Blue histogram (Cmd/Ctrl + 3) and drag the mid-tone slider to the right (to darken the brightness level of the blues).

Related Reading

Digital Photography: Expert Techniques
Professional Tips for Using Photoshop & Related Tools to Enhance Your Digital Photographs
By Ken Milburn

Hint: If you are working in a full version of Photoshop, you can record the above exercise as an Action. You will need to place a stop at each adjustment step in the Action, but you won't have to remember what sequence to do the steps in and you won't have to waste time searching for menu commands.

Note: It is best to do the above routine using an Adjustment Layer. This provides two important advantages: (1) You can automatically adjust other images that were taken at the same time and place so that they match one another perfectly. All it takes is dragging the Adjustment Layer to the open window of the next image, where it will be immediately applied. (2) You can nondestructively change this adjustment at any time by simply opening the Layers palette and double-clicking the appropriate Adjustment Layer. The dialog for that type of layer will open and you can then change the adjustments. Better yet, you can duplicate the Adjustment Layer before you make the changes, then turn off the original and readjust the copy. Then you can go back and forth between the two adjustments at any time by turning the appropriate layers on and off. Believe it or not, Adjustment Layers don't even increase file size.

Archive the Keepers

Once you've eliminated the duds and done your basic corrections, it's essential to archive these items offline. Don't wait until later: You'll never have time to do archiving of huge libraries all at once. Once the basic editing has been done, copy the new files to another hard drive and to a CD or DVD. CDs are easier to distribute because more users have the drives installed and because they only cost about 20 cents each. DVDs, on the other hand, will hold a lot more information. The fastest way to archive images is by using Album's Export command.

Hint: The Export command is also very useful for converting a set of files for Web use. I routinely copy the same files I archived to separate folders that hold an 800X600-pixel JPEG because I can then automatically post all those images to a web gallery or create a slideshow to be played on CD, DVD, PDA, or emailed.

Make a Project or Job Folder for Sharing and Communication

Once you've made sure that your images are basically presentable, by making sure similar frames are uniformly adjusted and that all frames are adjusted to show an acceptable amount of detail and contrast. Again, the easiest way to do this is by using Album (or iPhoto). Collect the photos you want to communicate with (say you want to discuss them with an assistant, client, or friend before you proceed with additional editing, interpretation, or special effects.)

Pages: 1, 2

Next Pagearrow