Night Cityscape Photography: Why Is HDR Necessary

By YPBlending, Tutorials

There is something magical about urban landscape at night when it transforms the concrete jungle into a different world. Flooded by millions of lights, it’s often an incredible sight to anyone who is caught in the moment.

Even if you’re not a fan of cityscape, the chances are, you'll still take out your camera or phone to snap a picture.

Because it is that mesmerizing!

cityscape photography at night tutorial

But most photographers don’t realise the one problem of doing night cityscape photography with a single exposure.

The brightest brights and the darkest darks are often clipped.

In other words, night cityscape photography is often a high dynamic range scene!

In this tutorial, I’m going to show you how to recover the information lost in the highlights and the shadows with XDR (extended dynamic range).

This article is all about paying attention to details!

Your effort will pay off with an image that is truly unique and stands out 🙂

The image below is an example of what you can achieve by blending details back into the clipped highlights.

The Classic Mistake

Shooting a typical night cityscape image sounds something like this:

You see a pretty night scene, you frame your shot, meter the scene using matrix metering mode and click. You might also use a tripod because the shutter speed is too slow for handheld.

Maybe you check your image on the LCD screen, maybe you didn’t.

The image looks something like this:

mistake of cityscape photography at night

A common mistake in shooting cityscape at night - a single exposure.

Nothing seems wrong, right?

Yeah, but…

On closer look, you’ll notice there are the highlights and some of the shadows are blown. You can’t read what the sign in light says because it’s overexposed.

Overexposure in an image taken at night?!

TTL Meter Doesn't Work Well In Low Light

By now, you must be wondering why the camera's light meter doesn't work well at night?  

I promise you it will start to make sense once you know a bit about how the camera’s light meter works.

In Theory...

These are what suppose to happen:

Night Scene With Predominantly Shadows

When you have a night scene with mostly the sky or the darker part of the scene in the composition, your camera will interpret these as the middle grey.

This means shadows should appear brighter in the image and highlights will inevitably be overexposed.

Night Scene With Predominantly Lights

Composition with mostly light trails, street lights or building lights will make your camera interpret these as the middle grey.

This means highlights will be better exposed and shadows have a higher chance of getting clipped.

However...

I often find it hard to tell whether a composition has more night sky or lights.​ Most of my cityscape images taken at night often have highlights and the darkest shadows clipped.

clipped highlights in night cityscape photography

Example 1: The brightest brights are clipped.

clipped highlights in night cityscape photography

Example 2: Similarly, the brightest brights are clipped too.

Bracketing Exposure For Night Cityscape Photography

The solution to this tricky situation?

Extend the dynamic range of your image!

Bracketing exposure in low light is almost done the same way as during day light, with a few tweaks.

But unlike during day light, you have the option to bracket handheld. In night cityscape photography, you have to use a tripod. Otherwise, your images will suffer from motion blur and become unusable.

Here are the steps you can follow or use it as a reference:

  1. Mount your camera on the tripod and compose your image.
  2. Set to aperture priority mode (Av), select an aperture of your choice. Remember, similar to shooting into the sun, the higher the aperture, the more defined the light burst will be.
  3. Instead of autofocus, I highly recommend focusing manually. This is because autofocus doesn’t work well in low light and you may end up with a blurry image (happened to me before!).
  4. Set the AEB (auto exposure bracketing) and take a set of bracketed exposure. Now check the images with the histogram on the LCD screen. Is there highlights or shadows clipping? If so, can you correct it with more bracketed exposure or exposure compensation? If not, you'll need to bracket manually.
  5. You can use a remote release or set a short timer to reduce the chance of camera shake.

My Personal Preference

Personally, I prefer to bracket exposure manually for night cityscape photography.

Why?

I often find AEB not able to capture the whole dynamic range. The part in the image that suffers is always the highlights. Note that I use a Canon 5D Mark 2 and it only allows me to bracket 3 exposures.

So, you can certainly get away with it if your camera can bracket up to 5 or 7 exposures.

The Secret Tool - Luminosity Mask

This is where the magic happens! 🙂

​After doing all the hard work, now it's time to combine the images to get the final result.

You’ll see how blending creates a gentle tonal transition to recover the details from the highlights. The result looks seamless and natural.

I use luminosity mask to blend in the details in the highlights. I prefer this selection technique because it is more intuitive when selecting highlights than any other ways of blending.

Learn more: The Kickstarter’s Guide To Luminosity Mask.

Luminosity mask creates selection based on the brightness. All you need to do is to select a brights mask that targets the highlights you need to blend. Simple!

Still confused?

Let’s go through it step-by-step together.

Step-By-Step Guide To Blend In Details With Luminosity Mask

Step 1: Preparing The Images

I use Lightroom to organise my images and do some minor editing. At this stage, I normally go through the multiple exposures I shot and apply any adjustments I want to all images. (e.g. lens profile correction, removal of chromatic aberration, straightening horizon, etc.)

step 1: preparing images for blending

Applying basic adjustments in Lightroom

Step 2: Stacking Images In Photoshop

If you’re using Lightroom like me, simply select the images you want by highlighting it, right click on your mouse and select Edit In > Open as Layers In Photoshop.

If, for any reason, you open each image individually in Photoshop, you can just drag and drop all files into one with the Move Tool.

Personally, I like to stack from the brightest exposure first. This means the brightest exposure is always at the bottom in the Layers Panel (Layer 1) and the darkest on the top.

step 2: stacking images

Stacking images as layers with the brightest exposure at the bottom

Step 3: Select A Brights Luminosity Mask

Generate luminosity masks based on the base layer. Base layer is the layer at the bottom of a blending set.

blending set

Now look through the brights luminosity masks and choose one that targets the brightest bright.

selecting a brights luminosity mask

Look through and choose a brights luminosity mask that targets just the highlights

Step 4: Blend In The Details From The Blend Layer

The blend layer is the layer above a blending set.

Start off by unchecking the visible icon to make all except the bottom two layers invisible. These two are your blending set (base layer at the bottom, blend layer on top).

To blend, select the luminosity mask you want in the Channels Panel (you should see marching ants). Then, click on the Layers Panel and click to select the blend layer. Now hold down Opt (Mac) or Alt (PC) and click on the Layer Mask icon at the bottom of the Layers Panel. This creates a layer mask on the blend layer with the selection from the brights luminosity mask and blends in the highlights instantly.

If the result looks a bit washout, try to blend it manually. This means creating a black layer mask for the blend layer first before selecting a brights luminosity mask. Then, paint on the layer mask selectively with a white brush only on the areas you want.​

blending with luminosity mask

The selected brights luminosity mask is applied to the blend layer

Step 5: Rinse and Repeat

Each time you’ve done blending the blend layer to the base layer, you move up in the Layers Panel. The blend layer now becomes the base layer and a new layer on top becomes the new blend layer. Now simply repeat Step 3 and 4 until you have all the layers blended.

When you select a brights luminosity mask for each blending set, choose the one that targets only on the highlights you want to blend. You may have to experiment with different brights mask to get the best effect.

I know all these sound a bit complicated, but I promise you’ll get the hang of it once the momentum sets in!

Learn more: Exposure Blending With Luminosity Mask.​

Don’t Stop Creating

If you haven’t realised, by the time you’ve finished blending the last layer, you have just created an extended dynamic range (XDR) image!

Just like any XDR, we simply DO NOT stop after blended in all the exposures. This is only the beginning of your creation.

Be creative in post-processing. Stylize your image, paint some light in!

The possibilities are only limited by your imagination!

​Over To You

How do you shoot and post-process night cityscape images? Do you share the same problem with blown out highlights?

I would love to hear from you 🙂 Let's share in the comment below!