Today's image, like so many others posted here, didn't start out looking like what you see. The sky comes from a 2009 trip and the harbor is about nine months later in the opposite direction. The distance between the sky and harbor is somewhere near 700 miles. Typically we take a trip along the Maine coast in October to shoot the foliage, the harbors and the lighthouses. We'll also take a trip before the schools get out in June to avoid the crowds and explore somewhere we haven't been before. Last June it was a loop trip that took in the Jersey shore (no, not that one - further down - Cape May), Chincoteague Island, Williamsburg, DC, Baltimore and central Pennsylvania. The "scene" for today's image is part of the inner harbor in Baltimore. A totally redone waterfront that is as far distant in time from Colonial Williamsburg as you can possibly get. The pano was made in early evening, but nowhere near as close to sunset as it appears. The dramatic sky was shot in Maine and was deep into sunset. Are there flaws in today's image? Sure, look at the building on the far left with the pyramid top. The shadow is on the wrong side compared to the "rising" sun. One of the Adjustment Layers that's not used too much was used to turn the blue water into, what seems to be, a reflection of the gathering morning light. To find out what it was and what had to be done, hit the "read more".
First thing to say is that nothing was done to alter the coloring in the sky. It's "as shot" as the sun was setting over a harbor in Maine. The harbor scene was shot late day and had beautiful blue water and sunlit boats. In order to warm up the water and buildings a Photo Filter Adjustment Layer was added to the harbor scene portion of the image. The way it was restricted to the harbor and kept out of the sky was by using a Clipping Mask. Clipping Masks tell Adobe Photoshop to apply whatever was being done to only the Layer directly below. The Photo Filter used is the first one the comes up in the dialog box when the Adjustment Layer is selected. It's name in the stack in "Warming 85". Back in the film days if you were shooting transparences (that would be slides) you actually use real filters to alter the color of a scene "in camera". In fact, that's exactly how the sky portion of the scene was shot. A Cokin P. 197 "Sunset" filter was hold in front of the lens as the exposure was made. The P. 197 is a graduated filter, meaning the effect is greater at one end of the filter compared to the opposite end.
A single application of the warming filter didn't match up with the richness that had been given by the "real" filter even when maxed out. One of the nice things about applying Adjustment Layers is that the effect can be cumulative. Just copy the Adjustment Layer (Ctrl J) and the setting and Blend Mode will be copied also. The second Adjustment Layer had to be clipped to the harbor scene (Alt click between Layers) as the first had been. Two maxed out layers matched up with the sky almost exactly.
During the production of today's image two sets of Smart Objects were employed. Smart Objects have taken over the workflow for anything being done at the gallery lately. It's just so easy to go back and "fix" anything that might have caused considerable rework in the past. Smart Objects are a great time saver and can be nested. I haven't found any max number that would be assigned to Smart Objects. Smart Objects were introduced in Adobe Photoshop CS3, but didn't get any traction until CS4 (Adobe added the line Filter/Convert for Smart Filters. Saying "Convert for Smart Filters" is a more user friendly way of saying "Make this a Smart Object". Apparently no one knew why they'd want to make something into a Smart Object, so making the reference to 'here ya go, use this to have a Smart Filter" worked and acceptance grew. Now, it's invaluable.