Leap ahead with these five quick tips for using the Urban Lightscape Photoshop plugin to correct exposure and balance lighting in your pictures.
Tip #1: Know when to use the smoothness slider
Placing two or more control points close together with respect to the setting of the Spread slider can trigger a sharp contrast in light and dark (see Figure 1). Increase the Smoothness slider to fix the problem while keeping the overall effect faithful to your intent.
Tip #2: Sharpen after, not before
Urban Lightscape relies on edge information to propagate and interpolate adjustments between control points. The purpose of sharpening is to exaggerate edges, but this interferes with Urban Lightscape too. The end result is more grain than you may like, so sharpen after using the plugin, rather than before, if this isn’t what you want.
Tip #3: Save contrast adjustments for later
Contrast adjustment is what Urban Lightscape achieves, but spatially rather than pixel-by-pixel. Increasing the contrast of an image may darken areas that you will later lighten with Urban Lightscape, amplifying noise. Consider deferring your final contrast adjustments until after you have used Urban Lightscape to get the spatial balance right.
Tip #4: Avoid JPEG images if you can
JPEG compression artifacts that are imperceptible to the human eye can still mislead the edge detection used by Urban Lightscape, and degrade its output. Within Photoshop, prefer using the RAW files produced by your camera, if available, rather than compressed JPEG images.
Tip #5: Use the sRGB colour space
The Urban Lightscape Photoshop plugin uses the sRGB colour space internally. Elsewhere in Photoshop, you may be using a different colour space, such as Adobe RGB. This mismatch will degrade the faithfulness of the preview image in Urban Lightscape, usually producing noticeably dull colours. To ensure that you are using sRGB, use the Edit > Convert to Profile menu item in Photoshop, and select "sRGB IEC61966-2.1".
Following the above tips should get you well on the way to getting the most out of the Urban Lightscape Photoshop plugin!