By Roger (1 February 2015)
Night time works great if you want to create something with a certain mood – either somber or exciting. The world looks different, with the bright lights and deep shadows. Even things as mundane as a traffic jam can seem more interesting.
I need to do more night photography, this year. I don't do this often enough. I've probably used the same excuses as you have: I'm tired after work; it's cold; it's hot; mosquitoes; blah, blah. The bottom line is if you want to get night photos, you need to go at night. Right? Well....
There are, however, other tricks for those who like to play with post-processing. There are ways to convert photos, taken in the daylight, into photos that your viewers will think were taken at night. Here is one of the many techniques to make that happen.
Open the image you want to convert in Photoshop. I highly recommend you open a copy because we're going to bend a few pixels.
In the layer panel, make a copy of your Background layer (Cntl-J) and convert it to a Smart Object (Layer→Smart Objects→Convert to Smart Object). By converting to a Smart Object, you get the capability to make adjustments, later, if you want to tone down your effects.
Now, we need to greatly reduce the exposure and make the color temperature cooler. Select your new Smart Object layer, and add a Camera Raw Filter (Filter→Camera Raw Filter). Move the Exposure and Temperature sliders far to the left. The exact numbers don't matter because you can always come back and adjust them. Didn't I just say that? Label that layer “Blue” for easy reference.
Here is a copy of what happens:
It looks perfect, right? OK, not quite. We've got some more work to do.
Select the Background layer, and make another copy. Now, make another Smart Object. You can see your new Smart Object, but the image on your screen didn't change? Don't worry; just label the new Smart Object – I'm going to label it “Orange.” Select Orange, and add a Camera Raw Filter. This time, however, we are going to move the Temperature slider to the right, to add the warmth that our eyes perceive in the dark. I also add some clarity to this filter. I have heard suggestions, from some folks, that they add to the warmth by increasing the saturation levels in the HSL (Hue, Saturation, Luminance) tab, but I usually don't go that far. That creates this layer.
After you accept the changes, the image will still look unchanged. Remember, you're in layers, and the Orange is underneath the Blue. Simply, move the Orange layer to the top. We are going to use this layer very selectively, so add a black layer mask, and the Orange disappears from your screen, again.
Select Orange's mask. With a very soft, white brush, sized about twice as large as the light source, and its Opacity set low (I begin with 50%), click once on the light. Voila! Now, use an even lower opacity brush (about 10%) to light the scene, highlighting the parts of the photo where those lamps would light. With your brush set to such a low opacity, you may need to click on a light source or area more than once. This allows the brush to build up and prevents you from putting the same strength in every area. Lights fade away as the distance increases, so this allows you to emulate that. There is no set solution; it is done to your taste. You get strange looking masks, like this.
I wanted to show you the mask and the many different variations you get as your white brush builds up. You can see there are very few places where it is pure white. (Remember, white reveals the layer; black conceals.) It seems complicated, but, after you've tried a couple, it is real easy to understand how this works.
Here is my first crack at this scene from Poland.
Those little alcoves on the basilica are lit at night (in the real world), by light stands near the end of the street. You can see the light stands when you zoom in. I wish I could have been there at night, but I was on my way to a wedding.
When you try this, show someone the final result first, without telling them what you have done. Ask them what they think about the photo. Listen to what they find wrong. If they, immediately, point out that it doesn't look like a real night shot, ask why not. After working on a couple of these, I think I could spot all but the best efforts, but most regular folks will just accept that it is a night photo. They'll find something else that bothers them.
I think I'll need to keep working at this. It was a fun exercise, but it doesn't look as realistic as I'd like. It, obviously, works only with scenes containing fixed points of light. I gave it a try on this lighthouse from San Diego. I don't know.... Is the beam of light too much? Maybe, I shouldn't light the middle room?