July 31, 2008
Auto-masking in Lightroom 2
The true stars of Lighroom 2 are the localized adjustment tools. For the first time, photographers can now edit their raw files using the adjustment brush and gradient filter tools. These allow you to apply all kinds of adjustments such as: darkening, lightening, coloring or sharpening an image. The following extract is taken from my new book in which I show how to work with the adjustment brush and auto-masking feature.
The auto-mask controls
The Auto Mask option cleverly masks the image as you paint with the Adjustment brush. It works by analyzing the color and tone of the area where you click with the Adjustment brush and only applies the effect to those areas that match the same tone and color. A succession of paint strokes will be linked as a pin group, and the brush strokes applied here don’t have to all be based on the same color; the Auto Mask continuously resamples as you paint to calculate the mask. In the following example I clicked on the warm-colored backdrop and dragged the brush around the areas I wished to paint in one swoop and you’ll note that the brush adjustment mostly didn’t bleed into the flower petals or stems. In this exercise, I show how I was able to use successive strokes to neutralize all of the warm-colored backdrop. The Auto Mask feature does appear to work remarkably well at autoselecting areas of a picture based on color, but to fine-tune the edges, you may need to do what I did here, and switch back and forth with the Alt key to erase areas where the Adjustment brush effect spills over the edges.
TIP
You can also hold down the Command key (Mac) Control key (PC) to temporarily switch the Adjustment brush into Auto Mask mode (or revert back to Normal mode if Auto Mask is already selected).
1. This shows the original photograph with a warm-toned backdrop. I began by clicking on the Adjustment brush to reveal the tool options.
2. I selected the Saturation mode, set the Effect slider to –100% (to desaturate completely), and started painting. Because Auto Mask was checked, the brush only adjusted the backdrop colors.
3. After finishing the main brush work, I switched to Edit mode, so that I could fine-tune the settings. In this example, I adjusted the Brightness, which meant I could also darken the painted area.
Hand coloring in Color mode
As an assistant, I had the privilege of working for a photographer called James Wedge, who was well-know for his work hand-coloring black and white prints. James had a whole section of the studio set aside for working with the air brush, inks and masking fluid. I was therefore intrigued to discover that you can apply a Color effect adjustment in Lightroom 2 to an image that had been converted to monochrome in Lightroom, and thereby imitate traditional hand coloring techniques. What is cool about this method is that the auto-masking is working on the underlying color data when calculating the mask.
The Color effect allows you to brush with color on your photographs and can be likened to working with the Brush tool in Photoshop with the Color blend mode. There are lots of potential uses for this tool: you could use it to make someone’s hair a different shade of color or change the eye color, or you might want to cool an area of the picture. In the example shown here, I started with an image that had been converted to black and white by desaturating the colors. The main thing to point out here is that I used the Adjustment brush in Color mode with Auto Mask selected. Although the previewed image was in black and white, it did not matter which black and white conversion method was used, since Lightroom always references the underlying color data when calculating the Auto Mask. The Auto Mask feature was therefore able to do a good job of detecting the mask edges based on the underlying colors of the flower heads, stems, and leaves.
1. This photograph was converted to monochrome by desaturating all the Saturation sliders in the HSL panel (you could also drag the Basic panel Saturation slider to zero, or convert to grayscale). I selected the Color effect and clicked on the main color swatch to open the color picker shown here and selected a green color to paint with
2. With Auto Mask checked, I brushed along the stems and leaves, switching between a broad brush (A) and smaller brush (B). I also used the Edit sliders to modify the color and increase the saturation.
3. I clicked Enter to OK these brush strokes and started a new set of paint strokes. This time I selected a yellow color and began painting the flower petals, again with the Auto Mask option selected.
Tip
You can use the color picker to sample not just from the ramp or preview image, but from anywhere on the Desktop. The trick is to click in the color ramp, hold the mouse button down, and drag the cursor anywhere you like to sample.
The Adobe Photoshop Lightroom 2 book
The Adobe Photoshop Lightroom 2 book, by Martin Evening and published by Adobe Press (Peachpit) is now available for purchase from the usual book shops and on-line book stores.
Now available for order at:
Peachpit.com
Amazon.com
Amazon.co.uk
This brand new edition contains 624 pages and has been fully updated for all the new changes to the program since version 1.0.
ISBN: 0-321-55561-9
List Price: $49.99 (US)