Introduction

Have you ever seen a photograph of a city skyline?  Of course you have.  When done right, it can be extremely beautiful and awe-inspiring.  For me, the most memorable skyline photographs are those with a colorful sky and well-lit buildings.  This combination, however, is almost impossible to capture in a single exposure, because the sky is typically most colorful just after sunset, whereas the buildings appear well lit sometime later.  The artificial building lights are most conspicuous after some of the natural ambient light has vanished.  So, how do we capture the beauty of a vibrant sky while maintaining a nighttime look to the skyline?  Read on, and I’ll show you how I do it.

Before we dive into the tutorial, let me first briefly mention the two programs I use to organize and “make” my photographs:

• Adobe Lightroom 2.6
• Photoshop CS4 (Version 11.0)

I use Lightroom to organize my photographs and make minor adjustments such as exposure, clarity and vibrancy.  For major edits requiring layers, I use Photoshop.  By the way, I’m using a Macintosh computer running OSX, version 10.6.2.

In the Field

Arrive at your location with plenty of time to set up and find your favorite spot.  Make sure you’re using a very steady tripod.  I can’t stress this enough.  Pick your spot, compose the image, and wait.  A cable release is highly recommended, so you don’t have to actually touch the camera to take a picture.  If your camera has a mirror lockup feature, enable it.  This will minimize tiny vibrations from the camera’s mirror movement.  If you haven’t figured it out already, the goal is to have the camera as steady as possible.

I typically bracket my exposures 1 1/3 to 2 stops on either side of 0 and shoot in RAW.  This “protects” me if exposure and white balance aren’t “perfect.”

With everything set up as above, autofocus (or focus manually if you prefer) on your scene.  Once you’re happy with your focus, switch the camera to manual focus.  The reason is, once light levels fall off and ambient contrast decreases, the camera might “hunt” for focus.  This can happen if you leave autofocus on.

As the sun begins to set, take pictures periodically to capture the changing colors in the sky and clouds.  It’s difficult to judge when the sky colors are “just right.”  So, don’t be stingy with your memory.  Click away!

Typically about fifteen to thirty minutes after the sun has set, the buildings’ lights will begin to stand out.  Take a few more exposures.  When you’re happy with the nighttime look to the skyline, you’re done.  Pack up and head home to process your masterpiece.

The Digital Darkroom

Typically, I import images into Lightroom and then do the major edits in Photoshop.  Below are the two images (fig. 1 and 2) I used to make my final shot (the one at the beginning of this blog).  The two shots were obtained 15 minutes apart.  The first shows a beautiful sky but not much definition in the skyline buildings.  The 2^nd offers a brightly lit skyline with good shadow detail, but lacking an interesting sky.  Below are the steps I took to arrive at the final photograph.  For the sake for clarity, I’ll refer to the colorful sky image as “sky” and the night skyline images as “night.”

Fig. 1, "Sky"

Fig. 2, "Night"

Step 1:  Open both images in Photoshop, and make sure your top window is the “sky” image.

Step 2:  Select and copy “sky” to the clipboard:  Command-A followed by Command-C

Step 3:  Select the “night” image to make that the active window.

Step 4:  Paste the “sky” image on top of the “night” image:  Command-V.  If not already displayed, make sure you can see the “Layers” pallet.  The layers pallet should now show the “sky” thumbnail on top of the “night” thumbnail.  I recommend you change the names of the thumbnails to “sky” and “night” corresponding to their respective layers (fig. 3).  You can do this by double clicking on the text adjacent to the thumbnail in the layers pallet.  Double click the text, NOT the thumbnail itself.

Fig.3, Layers Pallet with thumbnail names changed to "Sky" and "Night"

Step 4:  Change the blending mode for the “sky” layer to “lighten” (fig. 4).  The resulting image should show the buildings’ lights “shining through” to the “sky” layer (fig 5).  Examining my image, I’m still not completely satisfied with the look of the sky or the “hazy” appearance to the skyline.  Too much of the uninteresting sky from the “night” layer is showing through, and the skyline doesn’t appear dark enough.  If you are similarly troubled by your image thus far, follow the steps below.

Fig. 4, Change blending mode to "Lighten" (black arrow)

Fig. 5, Intermediate image after step 4

Step 5:  Select the “night” layer by clicking on its thumbnail in the layers pallet.  Then, under the “Layers” menu, select “New Adjustment Layer” –> “Levels…” (fig 6).  In the dialog box that appears next, be sure to check the box next to “Use Previous Layer to Create Clipping Mask” (fig 7).

Fig. 6, How to get to "Levels..." in Menu

Fig. 7, Layers dialog box. Be sure to check the box next to "Use Previous Layer to Create Clipping Mask" (black arrow)

Step 6:  Make sure the “Adjustment” window is visible.  If it’s not, make it visible by selecting it from the “Window” drop down menu.  Adjust the center gray triangle until the desired effect is obtained.  In fig 8, I’m including both the Adjustment window and the Layers pallet.  For my image, I set the gray triangle value to 81.  Note the increased conspicuity of the colorful sky and darkening of the buildings, exactly the effects I wanted (fig 9).  At this point, I’m pretty much done.  To arrive at the final image (the one you saw at the beginning of this blog), the only additional steps I performed were cropping, flattening the layers, and a little bit of sharpening.  As a summary, I’m including all the steps from the “History” pallet (fig 10).

Fig. 8, Adjustment and Layers Pallet. For my image, the gray triangle value is set to 81 (black arrow). The number for your image may be different.

Fig. 9, The resulting image after step 6

Fig. 10, All the steps from the "History" pallet

I hope you have found this tutorial helpful.  If I have been unclear in any way, please ask your questions by responding to this blog or sending me an e-mail.  I promise to answer your questions as soon as I can.  Happy shooting and have fun!