Tips to Improve Your Night Photography- Tip 3
First off, I am by no means the authority on taking wonderful and interesting night photography. This is not a comprehensive guide, but over a series of installments I hope to share some tips to improve any night photography experience. These handy pointers aren’t new, but they are some things I have learned shooting over the past few years and I thought I could pass them along to you.
Tip 3- Save Your Exposures.
In the previous two installments of Night Photography tips, we have discussed shooting during the “blue hour” and underexposing your night photos. Both concepts were introduced as ways of overcoming the somewhat limiting dynamic range capabilities of modern digital cameras in high dynamic range shooting scenarios. Today, I will introduce you to a neat trick that can save some areas that may fall outside of your camera sensor’s purview.
As discussed previously, when shooting a scene with a large dynamic range, it is very possible that for any given exposure there will be some values that are too much for your camera’s sensor to capture, being either too bright or too dark. This is especially true for shooting a cityscape at night. One particular offender that is always causing me problems is digital billboards. If I set my camera to properly expose the scene before me, I can always count on billboards to be blown out. If I expose for the billboards, goodbye everything else. Any object in a scene that is significantly brighter than its surroundings can cause this same headache, be it street lights or even a full moon.
Enter Exposure Correction
When highlight blow-outs are unavoidable, a bit of foresight and some Photoshop wizardry can be the solution. Exposure correction (at least that’s what I’m calling this particular technique) is, on its face, a simplified version of exposure blending, a technique popularized by Jimmy McIntyre that can be read about here. Exposure blending is a fairly complicated technique that relies on luminosity masks to combine multiple exposures, sometimes taken over a period of up to several hours, to create a final image where all aspects are properly exposed. While this technique is quite impressive and can yield some lovely results, it is not an easy technique for intermediate photographers and can easily be overdone. Also, to my taste, there is something very satisfying in capturing a genuine scene as it exists in real time, an image that is authentic, not manufactured. I subscribe to a natural approach to photography (well, as natural as digital can be) and even exposure correction for me can walk a fine line between the real and the manipulated. But, it can be justified when used correctly and with necessary restraint.
So let’s get into it. The first step is to take a bunch of images, a whole bunch. Now the key to making this trick work is to use a solid tripod and preferably a remote trigger. Find a composition that you are confident in and set your camera so that it won’t move. Use manual focus, so that you can ensure that your focus remains the same through every exposure, and start shooting. Bracketing can be especially effective. For the shots seen above, I bracketed the exposures at one stop intervals, setting the center exposure to be slightly underexposed, as if I were targeting this as a stand alone shot. From here, shoot as you have learned through our previous lessons and wait to get that perfect shot, the only difference being you will also have two or more additional exposures, one brighter and one darker than the center shot. Now it is important that the darker shot effectively exposes the brightest elements in the frame. If some elements are very bright, it may be necessary to include two or more underexposed frames, separated at one stop intervals to correctly capture the differing areas of brightness.
In this particular scene, there were several very bright elements, the brightest being the large LED billboard that can be seen below. At my center exposure, all detail in this and other areas was completely lost.
By exposing at one stop intervals, I captured 37 exposures over the course of 20 minutes or so and, upon returning home, selected my best grouping of three exposures spaced one stop apart.
The next step is to open these images in Photoshop as either TIFF, RAW or smart objects, depending on your preference, stacked one on top of the other and named appropriately “base”, “dark”, and “bright” to keep things clear. I’ll leave the stacking order up to the preference of the individual, though my preference can be seen below.
Now choose either dark or bright to start with and add a layer mask while hiding the other layer. Invert the layer mask by pressing Command + I on a mac or selecting image> adjustments> invert. Now all that should be visible is the base exposure. Depending on what layer you are working with you are going to “paint” over the areas that you want to either lighten or darken. This should be done carefully and subtly as with all things photography, a little goes a long way. Press “B” to bring up the paintbrush tool, setting the opacity to around 10%, and the paint color to white and begin lightly painting over the offending areas. Be careful to stay inside the boundaries of what you want to change, as coloring outside the lines can lead to haloing and other unwanted irregularities. If you make any mistakes, simply switch your brush to black to paint them away.
I cannot stress enough how important it is to work slowly and carefully, keeping your opacity low. With your “Dark” layer active, slowly paint away all of the overexposed areas in your base image. When satisfied, repeat the same steps with your “Bright” layer active to carefully brighten any areas that are too dark. If you have decided to include more exposures than these, the process is the same. Remember, the goal here is not to create a new image or composite, but simply to correct some minor areas that fall outside of your camera’s dynamic range capabilities. Keep things subtle and, as always, feel free to experiment. When finished, save the image and import into your preferred editing software and continue your processing in the same way as you normally would to finalize the image to your taste and vision. I hope this and other tips have been helpful and feel free to comment with any questions or suggestions for future posts.