Correct perspective distortion
Master the Straighten and Perspective Control panel
Converg ing vertica ls When snapping this shot of Smailholm Tower in the Scottish Borders (left), we failed to capture truly vertical lines. As the tower looms above us from its hilly vantage point, the walls appear to lean inwards as they rise. These converging verticals are caused by perspective distortion. The camera was also rotated slightly, creating a tilted horizon. Se nsor spots If you swap your lens around often then particles of dust can stick to the sensor, causing unwanted smudged spots to appear in photos. In this shot they’re particularly visible in the sky. An image with sensor spots is likely to be rejected when it’s submitted for sale as stock. Fortunately, Capture NX-D’s Retouch Brush can replace sensor spots with clear patches of sky in just a few clicks (see the walkthrough below). Stra ighten and Per spec tive Control Click on this icon to summon forth the Straighten and Perspective Control panel. This panel will appear below the Edit panel in a scrollable window. You can click on the fly-out icon at the top-right of the panel to undock it and then drag it anywhere in the workspace. Stra ighten tool Click here to summon the Straighten tool. You can then click and drag the tool to sit on a tilted line. Like a ruler, this will measure the angle of the tilted line and then rotate the image so that it runs parallel with the edge of the frame. It can straighten tilted vertical lines as well as horizontal ones. Stra ighten slider Drag this slider left and right to rotate the shot manually. This helps you to straighten tilted horizons or make a vertical wall run parallel with the edge of the frame. When you use the Straighten tool to measure a tilted line, this slider will automatically adjust to counteract the tilt. We used a 1.2 increment, which ensured that the tower’s left wall was perpendicular to the ground. Area s without data When you rotate a shot, you also change its composition. If you tick the ‘Include areas without image data’ box, Capture NX-D will add extra areas of black to the edge of a rotated frame to preserve its contents. You can then manually crop out these black edges with the Crop tool. If you leave this box unticked then Capture will automatically crop the shot as it is rotated to lose any black edges. Vertica l correc tion This slider counteracts any vertical perspective distortion. In this case we wanted the walls of the tower to run more parallel with the edge of the frame, giving the architectural structure a more stable and balanced look. Horizontal correc tion Use this slider to correct lines that converge horizontally. You’re less likely to need to use this option.