Northern Light season is about to begin in Lapland. Before we start though, lets learn how to get the best out of your photos, in other words, this time we will learn how to edit our images in Raw editor/Photo processing applications for online presentation or printing. Here we go!
If you are just starting your way on Nocturnal and Northern Lights photography, I suggest you check my tutorial on How to take Photos of Northern Lights first and come back here later. As I’ve mentioned in that tutorial, you should always be taking photos in Raw Image Format, at least for the purposes of Nocturnal and Northern Lights photography. Raw editing allows you to make much bigger adjustments than Jpeg, such as correcting exposure, changing white balance and many others. Most of consumer DSLR cameras are capable of shooting Raw. If you are not sure whether your camera can shoot Raw, I suggest you check this list first and if it does, consult your camera’s manual on how to enable shooting Raw. On Canon or Nikon cameras Raw can be enabled under the menu item “Quality” or “Image Quality”.
The drawback of using Raw is that your memory card will fill up faster, but memory cards are cheap enough nowadays! Another drawback is that before you can share the image on social networks or use it in a meaningful way, you need to process it. Raw image adjustments are processsed with Raw image editors. Photoshop, for example, has an inbuilt Camera Raw plugin which you use before the image is imported into the Photoshop. Increasingly popular are photo processors with inbuilt Raw capability and other useful features, such as Catalogue functionality. There are several photo processors out there, for example, Lightroom, Capture One, DxO OpticsPro and the discontinued Aperture app. I will be using Lightroom for this tutorial, but the Raw adjustment features are similar in other Raw processors. If you don’t own Lightroom, you can get it for as low as 10€ a month from Adobe.
For our today’s tutorial we will use one of the images I took in February 2016 on my way to Luosto Ski Resort. It was one of the most memorable nights of the whole Aurora Season 2016–2017 and if you want, you can read about this amazing experience. If you wish to follow the tutorial along with me, grab the original raw file here. This doesn’t mean, however, that you can use this image in your commercial projects or sell it to someone else. It should be used only for learning purposes.
I presume that you are already somewhat familiar with Lightroom (or similar applications) and have some basic understanding of their functions, such as importing and previewing images. We will not be covering those, but will concentrate on adjusting our Northern Lights image. This is our starting point for our adjustment.
The basic adjustment I’d like to start with is Colour Balance. As I am shooting Raw, I don’t really care what colour temperature I am shooting with, as long as it is not really weird to make it difficult to preview the image with camera’s screen. I can always change it later in post-production. The colour balance is measured in Kelvins (K) and stretches between blue (on the left side of the slider) and warmer (right). The basic “normal” white balance of a sunny day is 5200-5600 K. A cloudy day is 6000 K. There is also a Tint value which goes from green to purple. The right colour balance is found by adjusting both of the sliders.
Generally there is often a limited window of colour temperature where Northern Lights look natural (something like 3200–5000K). More precise value depends on the situation and lights sources. The main “mistake” I see with novice Aurora photographers is their choice of temperature. More often than not it is too warm (over 5200K) which makes Aurora Borealis too greenish and, arguably, unnatural. I have developed my own taste in retouching Aurora images and many times I just input some values with my keyboard into the Temp and Tint fields that I generally know are good for different lighting situations. You can also use auto Color balance while shooting but it rarely produces pleasing results for Nocturnal or Aurora Borealis images.
My starting point is 5200K temperature and +5 Tint, as those values were happened to be set in my camera at the moment. They are not necessarily correct or represent the “true” white balance of the scene. There could be many sources of light in one image, each with its own colour temperature, so many times you need to choose one “general” colour first. In our image there are at least 3 sources of light – moonlight that illuminates most of the image, especially foreground and the road and the trees, the warmer light spill from a nearby house (over the treetops on the right) and, of course, the Northern Lights themselves.
If you are not sure what colour balance your image really is after you shot it, you can use a White Balance Selector tool. It can be found next to the Temp and Tint sliders in Basic adjustments and it looks like a Color picker (Pipette or laboratory tool).
I often use White Balance selector to make my adjustments faster, rather than guessing. The way you operate it, is that you click on it once and your mouse cursor will change into that tool. You need to find an area in your image where you have the most natural white colour. Sometimes you don’t have this privilege, but our case we have the snow! When I hover over the snow on the side of the road with a white balance tool, it shows me the zoomed area. From that zoomed preview I can see that the snow is very greenish and yellowish. In reality the snow is rarely a neutral white, but adjusting white balance based on the snow gives us some starting point.
I click on that snow area and Lightroom automatically applies new colour balance values – Temp 4700 and Tint +28. If you are not happy with the result, you can redo it on another white area or adjust the values by hand. This adjustment made the image more cooler and added magenta to counter the greenish colour. Temperature of 4700 is a rather warm for Northern lights images, however, the image is partly lit by the moonlight, which reflects the sun’s warmer tint of light.
Of course, this adjustment is a also matter of taste and one could make it warmer or cooler, but it looks fine to me:
In the next step we will be adding some contrast. In addition to the “regural” Contrast adjustment (+31) we also have a Clarity slider. The contrast stretches the highlights and the shadows of the image, but doing it to the image as a whole. Clarity adjusts contrasts selectively in midtones by evaluating the differences between luminosity values of neighbouring groups of pixels and making the contrast between them more visible. You have to be careful with that slider, because it can easily make your images look unnatural. For this particular image, however, the high amount (+43) works well, as all of the details are of similar and rather small sizes (the trees and “accents” of Northern Lights).
This is the result. To be honest with you, this is pretty much what I’ve seen with my own eyes. Northern Lights are rarely too saturated (although I’ve seen these too!) so if I would aim for “realistic” adjustment, the result would be good enough.
However, we want to go further and make the image pop out! Contrast adjustment has made our image richer, but it also darkened it. We have to rase exposure (+0,40) and some shadows (+0,25) to lighten up the image. We are also going to increase some saturation (+6) and vibrance(+29), but overdoing them would spoil our image. Here are our basic adjustments settings:
We are also doing some Tone Curve adjustments (found below Basic adjustments), but this is just another way to play with the contrast. Curves let you adjust contrast in a more flexible way than normal contrast adjustment. To operate curves you click on the curve to create some adjustment points. One is enough to start doing adjustments, but here we’ve made 3 separate points, one in the shadows, in midtones and highlights respectfully. We are increasing the midtones by a big amount and raising the highlights too. With the third adjustment point in the shadows we’re just keeping them where they are:
We’re done with basic adjustments and now can concentrate on different parts of the image and adjust them separately. The result so far is below:
There are many tools in Lightroom, Camera Raw and similar programs to allow this, but gradient adjustment is the most basic one. There are two types of gradient to use (starting from Lightroom 6.0) – linear and radial. In Lightroom you can choose this adjustment in the tab between Histogram Basic adjustments. By the way, its proper name is “Graduated Filter”
We are going to use linear gradient to adjust the foreground of the image (the road and the forest), as well as the sky with Northern Lights. We’ll start with the foreground. In order for you to see the gradient area better, I’ve coloured it red, but obviously I am not applying the red colour to the image. The good thing about gradient adjustments is that you can apply the luminance and colour adjustments independently of your main adjustment – gradient adjustments are coming on top of it. Here I want to make the foreground darker to accentuate the Northern Lights. I am reducing the Exposure a little bit (–0.17) and adding some contrast. Just a touch!
My second gradient adjustment applies to the sky. I am colouring the area in red again in order for you to see where I am making the adjustments. I add some Exposure (+0.20) and a touch of Clarity and Saturation. As I’ve mentioned before, those need to be used carefully!
After two gradient adjustment here is our result. Looking much better! As you can see, we have changed the focus to be more on the sky than on the foreground. There’s one more thing, however, that I could do. The upper part of the sky area of the image looks too luminous now as a result of the previous gradient adjustment.
We are applying another gradient to the sky, but only to the upper part.
Here the settings for this third gradient. We are making it just a little bit darker by setting the Exposure and Highlights lower and raising contrast. As you might also notice, we are making colour temperature cooler and blue (-11). This is a purely stylistic adjustment as I want to make the sky and Northern lights more bluish, as I think it is more smooth and pleasing to the eye.
This is what we’ve got so far:
Our image looks great, but still it is a little bit soft, so we need to make those details pop up out. We will move to sharpening and noise reduction settings. These can be found in the Detail tab of the Develop settings. This is how they look like by default:
In order to sharpen it you must set the amount, which is self-explanatory, and radius. Radius is how big the “net” of sharpening is applied to the image. Generally, the bigger the image, the bigger the “net” must be. Also, if you know for sure that you are going to print the image and export it in full width, you will need to use a bigger radius, otherwise your sharpening result will not be visible after being printed. If you are working with medium-sized or small images, use a smaller radius. The Detail slider sets up the “grain” of the image, but at higher iso settings at which Aurora images are often taken it is working against us and brings up the noise so I will leave it at default value. Masking takes some of this effect back and “blurs” the image to hide the grain. I am not going to use it because I will be applying noise reduction anyway.
Because my image is well lit (that moonlight really helps!) and my ISO is of moderate 1000, I do not need much noise reduction. In this case I only use 25% noise reduction, but in many cases I need to go further. There are many fine-tuning settings to be done here, but just working with Luminance slider will bring good results in many cases.
After the sharpening is done, this is our final result!
These are rather subtle adjustments but work well enough. There are many other adjustments that are possible in Lightroom. We could also take it to the next level by opening this image up in Photoshop and doing some post-production there, but I think the result is good enough!
Take care and hope you’ll catch some epic lights this season!