Editing the Milkyway with just Lightroom, can this be right?
Milkyway & Lightroom
Lightroom is a brilliant tool in Photography, it allows me to see the potential in a photograph extremely easily by making only a few adjustments. For my astrophotography this is no different, I will import my images to Lightroom, quickly browse over them and then select and play with the ones that I think are the most compelling. Once I have found my two or three photos that I want to keep from a night shoot I will then really process them in Photoshop, but this can be a lot more complicated and time consuming so lets just focus on the basics for today.
I have picked an image that I took at Catherine Hill bay, on the New South Wales coastline, and one of the reasons I shoot at "Catho" is the relative light pollution levels are pretty low for the region. I have included the RAW files and a preset with all the settings I used to come up with my results so that if you don't have anything to work with you will have no excuse to practice.
Divide and conquer
In any photograph there are several parts to it, be it subject, foreground, or elements these things are all important. One of the difference between Photoshop and Lightroom is that Lightroom doesn't use layers and so this means if we want to target areas and process them independently we need to think about where they are, and in what order we want to process them. For me I divide my photos into three simple elements;
- Galactic core or primary subject.
With my three elements defined I also need to think about in which order I will treat them, as if you recall we can't actually use layers. Essential one element will be a so called "base" layer and the filters that we use will adjust out sub-regions without affecting the base layer. For me I always start with the sky, and the reason behind that is generally speaking it will take up the largest portion of the photograph so it makes sense to make it the base layer, I then process the foreground, and lastly the Galactic core.
Setting up your base layer
Really what we want to achieve here is getting the sky to look and feel as natural as possible; we're first going to tackle the colour cast and temperature of the image. This photo I shot quite warm at 4700K, and I will admit this is unusual for me as I normally would shoot much cooler but as we have shot in RAW this wont be an issue. In the end we can add a little colour here and there to adjust the photo to make it pop out a little but we first want to have a natural and netural photo and so we are going to use our histogram in the top-right of the develop module to tell us when our colours are at neutral.
The histogram itself can't be adjusted, in case your wondering, but we can adjust what it's telling us by adjusting a few sliders. We are going to focus White Balance area in the Basic area, and the adjust our Tonal Curve. If you have in your photograph an area that you know is a natural colour then you can quickly adjust the WB by selecting the Eye Dropper tool and clicking on that area. If it is over or under exposed it will not work; the other way we can do this is by using the temperature and tint sliders. I could tell you that around 4000K is where it should be, but really the histogram is what you need to check. Slide it to the left or right until you see all the little humps aligning and for the most part the wave form looks grey as you can see in the example above. I brought the temperature down to 4081K and the tint to -20 and that his brought the majority of the large mid tones into neutral.
We can also use our Tone Curve to adjust specific areas of the histogram; firstly we want to make sure you are able to adjust the curve with points, so in the bottom right hand corner on the panel you will see a little line with a dot on it. Hover over and it will either say "click to start editing with Points Curve" or "click to start editing with Points Curve" if it is the latter of the two then click because we want to edit the Points Curve. To get more specific you can select which channel you want to use, either R (Red) G (Green) or B (Blue) or all three combined. There is no formula here, it really is a trial and error but in my example I have made little or no changes to Red Channel, small changes to the Green Channel, and almost all of the changes were in the Blue Channel.
LETS GET CREATIVE
Now that we have a nice blank canvas so to speak this is where you eye is the best judge of how your image looks. As I am still working with just the Sky component of my image then I am going to play with just the Tone sliders. This is a very quick and easy adjustment, and you don't have to worry to much about it as you can always come back to this part if you don't like how it's all looking.
- Firstly I am going to drop my exposure, this can be down to any value it really just depends on your image and how it was exposed. In this image I am going to come down about 2/3 of a stop (-.66) which will darken the entire image, but remember we are just focusing on the sky at this point;
- To add a little more black and white-ness to the image I am going to really bump up that contrast to around +35. In the past I have pushed that even higher, so experiment and see how it looks for you;
- My highlight I drop quite heavily as well to around -50, and my shadows down to -25;
- Lastly I will push up my whites and blacks, as this will push a little contrast back into the image after dropping those highlights.
A real point to remember here is that we are trying to make the sky look beautiful, but realistic too. When I look up at the sky I see black and white for the most part, so when I process I try and keep that in mind. When it comes to the Galactic core, your colours will really pop out, but for the dark parts of the sky I suggest trying to keep them black.
Bring up the foreground
Remember how we mentally separated out image into three sections? This is where we really begin to separate out image. If you have a linear foreground, by which I mean the transition from foreground to horizon is straight, select the Linear Gradient tool which is just under the histogram ( or press M) and drag that over your foreground. If you have a none linear foreground then perhaps you should use Adjustment Brush (or press K) and paint on the masking area for the foreground. If you press "O" you will see the areas you are either painting or dragging over that will be affect by that mask and hit "O" once again to turn off that feature. Once we've selected the area we wish to isolate/modify with our mask we can then start to bring up the foreground detail.
You're going to need to over come all the reduction from when we adjusted the sky, generally I start with my exposure and bump that up which will do most of the work for you, after that it's time to bring up the detail in the shadows that are probably still a little dark. The idea here is that we bring up the foreground so that most of the detail is visible without introducing great amounts of noise.
Normally I would tackle noise with Photoshop, and its usually one of the last things I do; however as we are using Lightroom we are going to do it as we go along. Using noise reduction in any application has one big disadvantage, and that is loss of detail. If we using the noise slider for just the linear gradient filter then we can quickly see what I mean.
If you look at the images above you will see three stages of noise reduction. The first image has no noise reduction and you will see all the detail of the image, but you will also see quite a lot of colour noise as well. The second image really is to demonstrate how much detail loss you will get if you push the slider all the way to the right, and the final image is what I am using in this example which is a nice balance between colour noise supression and detail loss.
Now For The Fun Part
The last part of the image that we are going to tackle separately is the galactic core, and really this is the main subject or feature of the image so we need to be careful in how we approach this. Our goal here is to introduce nice colour tones, brighten the core, separate the clouds from the dust lanes, show the detail, and of course not introduce any extra noise. But how are we going to do all this?
Again like the foreground we are going to use a filter or mask an area except this time it will be the radial filter. In addition we also need to over come the reductions set by the base layer as we did without foreground, so bumping the exposure up will pull that up nicely. Then adjust the contrast to give the whole filter area a more "pop" as they say and set it so that the black ares match roughly to the rest of the sky. When it comes to highlights vs whites I will push them in opposite directions to try and bring up a little more detail in the light areas, and I will do the same with the shadows vs blacks as well. By doing this it creates a kind of s-curve in the upper a lower regions of the tonal curve. You could probably achieve the same with a tonal curve adjustment however that will apply it to the whole image and we just want to target this Galactic core.
The next part is really a matter of taste in my opinion, but clarity can be a bit of a hot topic at times. Clarity if you're not familiar with it will give off the illusion of make an image soft or sharp to a degree. It does this by flattening the contrast in the mid tones. If we push the slider to the right you will see the galactic core pop out with even more detail, in the other direction and you will see a bit of a mystical glow. I personally push it to the right a little, but not all the way because then it starts to look unrealistic, which is what we are trying to avoid. I will also push the vibrance up, and saturation up. I think vibrancy and saturation is where I see a lot of over processing errors occur so don't be tempted to push it too far, you just want it to punch out enough so the copper tones, and some of the other cosmic colours just begin to pop off the screen.
So now that we have treated our individual areas we really have a nice balanced image going on, but we can do a little more to really steer the eye into the image, and give it just that little bit extra to more of that wow factor.
I am mostly going to work from top to bottom in the panel here, and first of all is the tone curve, I know we've touched on this before but I want to make a few further adjustments. In this image I think that black are just too deep, so on the curve I am going to bring them up, and drop my mid tones down a little. This gives the appearance of a slightly drier look, and it might not look great now you'll understand why shortly. Adjusting my mid-tones brings in a little more detail into that white area of the core but it will also drop the overall luminescence of the core as well. So I will also head back to my radial filter sitting over the core and increase that exposure a little to brighten it up again. Remember it is a balance game, you can't do much with affecting at least something else.
As my stars seem to be really blue at this point I am going to jump down to the blue saturation and drop that down by half. Again you don't want to remove all the blue, you just want it so it looks balanced. You may not have to do this in your own example, but certainly in mine I do.
Sharpening, like noise reduction, is also a little tricky. One tip I picked up years ago about the subject is to always zoom into 100% to see the affect its really having. You can do this by pressing the space bar, or left click of the image when you see the magnify symbol. In the Sharpness area you have 4 sliders, for the most part you wont ever really touch Radius or Detail but to quickly summaries what they do I will touch on them.
Sharpness is essentially adding amounts of noise to an image to bring out detail; noise when you look at it closely kind of resembles sand. As you increase the Radius, those grains of sand increase in size, and when you increase the Detail you visibility of those grains. This leaves us with the Amount and Masking sliders; the Amount slider I think is rather obvious it is just the amount of the grains that we want to use; however what masking does which is really cool if you hold down CTRL or Command and select the masking slider you will see the entire image go white, slide it to the right and you will slowly start to see the edges within the image pop out. What this is doing is applying a mask to the image so that sharpening is only applied to the edges or the white areas of the mask.
So lets apply out sharpening, I usually push the amount quite high, usually to the start of the red indicator. Radius, and detail are always in the lower one third of the slider but again that can depend on the image. Finally my mask setting is also really high if not all the way to the right as I just want to sharpen the edges and not introduce noise into the dark areas.
Onto Noise Reduction, the main part here is actually colour noise reduction. I brushed over this topic previously so I will just tell you my general settings.
- Luminance is set around 10;
- Detail is set to 50;
- Contrast is set to 10;
- Colour is set to around 25;
- Detail is set to 50;
- Smoothness set to 25;
I really only adjust the Luminance and colour sliders, the others I usually don't mess with too much like the Radius and Detail sliders for sharpness.
Finally the last detail that I adjust is the vignette appearance. This is a really useful tool but can, like saturation, be over done.
There are two methods of approaching this one is using the Effects panel and the other is by using a Radial filter much like we did for the core.
So lets talk about the Effects panel approach first. You will see on the top "Style" and you have three options here. Highlight, Colour, and Paint I only ever use the first two of these.
Basically the Highlight mode will allow you to recover the highlights in the darkened areas; however you will like get colour shift in the darker areas. Colour Priority does the opposite; you can't recover the highlight but you will not colour shift either. Which you use depends on your taste, for astrophotography you might find the highlight option useful as you can bring back some of the dull stars in the dark edges. The draw back to both of these is that you can not target the centre of the vignette, which means the eyes might not be going exactly where you want them. We can get around this by using the radial filter once again instead.
Things to remember is we don't want to loose that detail in the shadows so boost that a little, while you drop the exposure to darken the image. You might get the sense that the transition is a little harsh so open the feathering to around 80-85 which will also help. I also consider using clarity here as well just to soften the edges while the over all image detains its detail. The very very last thing to remember to uncheck the invert box so that it works from he outside in.
I know this all might seem a like a lot of information, but with time it will become second nature and you will be able to make all the adjustments in just minutes.
I really hope you found this useful, please feel free to comment below and give it a like if you enjoyed this. With enough support I will keep producing these totorials on my own journey to help yours along.