Autumn colour: A Lightroom workflow (part 2 of 2)

we are hoping for something between an American gothic and Victorian English feel. To help do this, I changed the lighting

The first part of this article can be found here (opens in a new window/tab).

In this article, we will see how we can create the  first image  below from the second image below (taken with a Nokia N95 series cell phone’s 5MP camera).

Autumn Colour
Autumn Colour
Unedited source (Nokia N95 camera phone)
Unedited source (Nokia N95 camera phone)

As we saw in the first part, there are several things wrong with the initial image (blown out skin and sky, colour cast causing colour to look washed out, no real framing, etc).

In the first part, we also defined an intent and backstory for our final image. In this concluding part, I will go through what I did in Lightroom to complete the piece.

Framing

Reducing the image to tones
Reducing the image to tones

The first thing I did was reduce the image to tones by selecting the ‘B&W Creative – High contrast’ preset. This removes all colour and adds contrast. The main thing this preset does is to reduce saturation to -100 (no colour).

Temporarily reducing saturation to -100  is always a good thing to do when cropping and reframing an  image, because it allows you to see the underlying subject(s) and lighting of your image clearly.

Cropping

By selecting the Crop tool (yellow arrow), I was able to straighten and better frame my image. There were two driving factors here; I wanted to form some horizontal/vertical straight lines (you can see which ones I chose via the green lines).

I also wanted to create a horizontal rule of thirds (red lines) via the crop.

Finally, I removed some of the image from the top and bottom during the crop. Both these areas contain nothing of significance, and would detract from the scan direction I want the viewer to take (left to right) by adding a conflicting and less desirable up-down scan.

Ambience and shadow

As discussed in part one, we are hoping for something between an  American gothic and Victorian English feel. To help do this, I changed the lighting.

First Graduated filter (before: left, after:right)
First Graduated filter (before: left, after:right)

To change global lighting or add shadows, I use the Graduated Filter tool. Although a real graduated filter is generally used to darken or tint the sky, I almost never use the digital version in Lightroom in this way; it has much more potential when used for creating ambient and light/shadow/chiaroscuro effects on the main subject.

The first step was to set the ambient light; although the image was taken in mid day sun, I wanted to emulate a crisp early morning. To do this, I added a graduation that darkened the top left corner at the same time as adding contrast, falling off towards the middle. Why would this suggest a crisp early morning? As the gradient follows the perspective lines of the fence, we see a gradual whitening and loss of contrast as we move along the fence and to the distance. One cause of this would be a very light early morning mist.

Our gradient also has a happy side effect of fixing the blown skin tones on the face. Bonus! (If this had not fixed the blown out skin tones, we could have fixed it separately via the adjustment brush later).

Second Graduated filter
Second Graduated filter

A second gradient darkens the foreground. I have chosen the Exposure and brightness so that the colour of the shadow is the same tone as the figure.

You can no longer see her feet as they merge into the shadow (yellow arrow). Although technically unrealistic, this gives the figure a different sense; she is now part of the shadow rather than being merely in shadow.

Image completed for light/shadow and tone

Here’s the image so far.

Image completed for light/shadow and tone
Image completed for light/shadow and tone

As you can see, we have fixed almost all the problems in the original image already! We have imposed good framing and have the beginnings of a style in our image.

Setting an image to B&W and then using the gradient tool to add shadows and lighting is something I do often in Lightroom. By changing the tones and lighting/shadow of your image via gradients whilst viewing the image in black and white (tones), you can drastically alter the feel of your image with ease.

As an aside, I noticed that many of the search results for the first part of this article were along the lines of ‘how to get a gothic style in Lightroom’. Well, you know half of the equation now; use the gradient tool to create lighting in that style.

Colour

We now move to adding the colour back to the image. We could just set the saturation back to normal (0%) but there is a better two step way that gives us more control;

'Neutral colour image', ready for recolouring
'Neutral colour image', ready for recolouring

Step 1: First, raise the saturation by a tiny amount so that you now have a little colour. Then, raise the vibrance by a lot. In the image below I raised the saturation from -100% (no colour) to -88%, then raised the vibrance by 33%. This has the effect of making all the colours low and equal; the low saturation gives you almost no colour, and a high vibrance normalises your colours (makes them all the same intensity).

As the entire colour intensities are low and equal, you get a faded colour image, as seen above. I call this the ‘neutral colour image’.

From here, you can colour the image as you wish simply by boosting/cutting the colour saturations. You can also fine tune the light/shadow per colour range by altering the colour luminances. Finally, you can re-colour (swap colours) via the hue sliders.

Step 2: make the colour balance fit your intent by varying the colour sliders.

Re-colouring the neutral colour image
Re-colouring the neutral colour image

I boosted the oranges and yellows (to give me the autumnal leaves) and decreased Aqua (Lightroom’s name for cyan or blue-green) to remove the bluish colour cast in the original image.

More importantly, you can probably see here that I could have boosted/cut other colours, and this would have given me a totally different image.

Finalising the edit

There’s some minor issues remaining. Some of the leaves right at the bottom of the image are too bright and detract from our main subject.

Also, you can tell that the figure is wearing trousers because you see a small gap between the legs. I would prefer the figure to be more ambiguous, and by removing the gap we are more likely to believe she is wearing clothes from a much earlier age.

Spot removal
Spot removal
By removing some of the dots above, we end up with the final image;Autumn Colour;
Autumn Colour
Autumn Colour
Click here to show a larger version (1200×840, opens in a new window/tab).

Conclusion

This article suggests a quick and consistent way to fix images where a significant amount of change is required (i.e. significant crop is required to strengthen composition, and drastic changes in tone and colour balance are required to set a style);

  1. Reduce the image to black and white by reducing saturation to -100%.
  2. Crop and rotate to set the direction you wish the image to be scanned by the user’s eye, and to set the direction of the dominant line(s).
  3. Add or change global lighting and shadow via the graduated filter tool (you can also use the fill light slider, but don’t change it by more than 3-5, because it has a big effect).
  4. Normalise the image colour by increasing saturation by 5-15% and increasing vibrancy by 30-50%. This gives you a faded, neutrally coloured image.
  5. By using the colour sliders, re-colour the image in line with the tonal changes made in 2.
  6. Make local changes (spot removal, local adjustments via the adjustment brush) to finalise the image.

The previous article in this two part set discussed ways of deciding exactly what post processing needs to be performed on the image, and how to decide what style changes will be imposed on the image.

Notes

  1. The source image is a JPEG. This limits my ability to expose-up in my edits, and is one reason why I chose my edits such that they tended to darken (under-expose) the image. This has the side effect of hiding the noise that woudl otherwise exist (cell phone cameras are much more noisy than a typical DSLR even aside from the fact that they export to JPEG only).
  2. During my crop, I used horizontal/vertical dominant lines. Other images may have other dominant line directions; imposing a slant to the horizontal or vertical is often more desirable because it creates a less stable (and therefore more dynamic) framing. A curving dominant line direction can also be desirable.
  3. As an aside, the image in this post shows the view from the other side of the ridge at the far right of ‘Autumn Colour’. The two images were taken less than five minutes walk from each other, albeit at different times of the year.

Shooting to the right (and why it can be a bad idea)

Here’s why no camera manufacturer has added automated shoot-right compensation; shooting to the right has a consequence; you lose accurate color reproduction.

Shooting to the right is practically a recommended technique for digital cameras. The theory is all over the internet, yet actual examples illustrating the stated improvement in output in the actual image are thin on the ground. You will find few, if any. Here’s why.

The percentage of digital noise in your image is reduced if your image is taken as bright as possible (‘shot-right’ or ‘exposed-right’), and this occurs if you

  • shoot in RAW and
  • keep your histogram to the far right as possible but without actually touching the right end of the histogram (to avoid clipping).

Your image will come out of the camera brighter than it should be, but you can fix that by reducing exposure in your RAW converter (Lightroom, etc).

There are many people who recommend shooting-right. Thomas Knoll (co-creater of Photoshop) is a fan, as you can see here. Adobe seem to recommend it as well, as can be seen in the Adobe white paper here (link opens a pdf in a new tab/window). If the concept of shooting to the right is new to you, I recommend that you read at least one of the links before proceeding.

Both the links give a good technical background to the issue (probably because both Knoll and Fraser are primarily looking at the technical imaging issues). As we will see, this means that they may be underplaying an important artistic consequence.

There are also other articles, such as the ChromaSoft Blog that tell us Shooting-right is ‘just plain wrong’, because it doesn’t actually reduce noise or for that matter make anything better  (and simply altering ISO is a better bet). As we shall see, there actually is a good use case for shooting-right; it is just not applicable to noise.

In the first two links, there is one unanswered question; if shooting to the right is so important to achieve low noise, why don’t cameras do it by default?  For a given aperture, shutter and ISO, the camera could easily look at the histogram and do the shift digitally via an automated exposure compensation behind the scenes, but put information in the RAW file that causes an automatic shift back the left in RAW conversion. Surely that would produce a competition killing camera feature?

Here’s why no camera manufacturer has added automated shoot-right compensation; shooting to the right has a consequence; you lose accurate color reproduction.

Shooting to the right gives you a less noisy image (better signal/noise ratio) out of the camera, yet when you reduce exposure back to the left in post processing, your image becomes slightly washed out. This occurs because the red, green and blue components of your image do not change at the same rate as you overexpose and then underexpose the image, probably because your camera is doing all sorts of non-linear things behind the scenes (and even if your RAW converter knew about them by your choosing the most appropriate camera profile, there is no guarantee this will fix the issue). This non-linearity always causes the colors to change, and in the case of shooting to the right, the result is a more washed out photo.

Consider the image below. It is an amalgamation of three shots I took of a color card placed in shade. Each square contains three strips;

Colour card, showing effects of 'shooting-right'
Color card, showing effects of ‘shooting-right’

The strip marked 0 (leftmost) is the image taken at normal exposure (and, for the sake of argument, shot at the camera’s base ISO), reproduced with no post processing. We are not shooting to the right and the lighting has been chosen so that the top 30% of the histogram is empty. This gives us a noisier image than the camera is capable of, but the color is as accurate as the camera can get under the setup conditions.

The strip marked +1 is the same image but taken with exposure compensation set to +1 to better fill the top end of the histogram, then corrected in post production via a subtraction of 1 exposure value.

Similarly, the strip marked +2 is the image taken with exposure compensation set to +2 (making the histogram almost touch the right end of the scale), corrected in post production via a subtraction of 2 exposure values. This image would give us the least noisy shot the camera is capable of at our selected aperture, shutter, ISO and lens.

You would expect the three strips per square to show slight variation in brightness because of slight errors in exposure value between the camera and RAW converter. You would also expect to see differences in noise.  Unexpectedly, what you see is a loss of color and no change in noise!

When you shoot-right and then try to correct by exposing back to the left, your colors become washed out. Worse still, the colors are all washed out by different amounts so it is not trivial to get the color back to an accurate state.  As if that is no bad enough, the worst thing of all is that the colors most washed out are those associated with skin tones and there is no gain in noise!

This makes a kind of sense when you think about it. When we expose up then expose back down digitally, we assume that adding a brightness (say +1/2EV) and then taking the same brightness away (-1/2EV), gives us the brightness we started off with.

The problem is that this situation never occurs in the real world: any natural light source changes color as it changes brightness (especially natural light coming from the sun) and our eyes are calibrated to those natural light changes: human eyes cannot perceive a pure change in brightness without also perceiving a color change, because that is what happens in the real world.

The camera is possibly making color adjustments as we change exposure compensation so that we perceive a pure brightness shift, but Lightroom and Photoshop doesn’t know what that color adjustment was so when we expose back down, Lightroom/Photoshop do not reverse the color adjustment and we thus see a slight change in color.  It may even be something far simpler (camera sensor linearity issues), but whatever it is, cameras do not maintain perfect color with exposure.

What to do?

When you will be post processing your images

Thomas Knoll is recommending shooting-right because he’s assuming your going to be using Photoshop afterward. Although you can’t perceive the extra information, post processing may bring out the enhanced detail associated with the extra information as you open up certain tonal ranges. If you will not be processing your images after shooting and your images are within normal ISO ranges, shooting right has little effect.

Thomas Knoll is right when he tells us that there is more information stored in the RAW file for the highlights. What he doesn’t tell us is why.

A camera stores more information in the highlights and less information in the shadows because that is where our eye sensitivities lie. We are more sensitive to noise in highlights than noise in shadows because we perceive highlights better. If we try to reduce noise by creating a brighter image, it will technically work (signal/noise ratio is better), but because our eyes are more sensitive to  highlights, we see more noise even through there is less of it, so perceptually, we see the same amount of noise!

Put another way, camera manufacturers put more information towards the right of the histogram simply because we see noise (and everything else) at that end of the histogram better; if we actually shoot to the left instead of the right, there is mathematically more noise in the image (worse signal/noise ratio), but because our eyes are less sensitive to noise in shadows we still perceive the same amount of noise. You can shoot to the left or right as much as you want but your eye will not care; it doesn’t do the math and sees the same amount of noise. This occurs because the camera is (again) specifically calibrated to reflect the eyes’s inaccuracy.

This leads to the one reason why shooting to the right is a good thing; when you are shooting an image that you will be postprocessing later in such a way to make portions of it brighter (i.e. dodging) and true color is not a big issue.

Consider the following example; I am shooting an image of someone wearing a dark suit. Color is not important as the overall key is dark anyway; the overall image is tonal. I shoot to the right, then expose down to the left in lightroom. The suit shows no texture, so I dodge (brighten) it. Two things happen;

When I shoot to the right and expose down, the shadows now contain more information than they would otherwise, but because my eyes can’t see into shadow, I don’t notice the difference.

When I  dodge the suit to make it brighter, I start to see the additional information, and shooting right begins to work in my favour (if I did not shoot-right in this case, the suit would become muddy and indistinct when I open up the shadows; I begin to see the lack of information in the shadows). 

Why don’t we just alter ISO? Because shooting to the right adds no new noise (it enhances signal/noise by increasing signal only; noise stays the same). ISO is physically an amplifier stage than sits after your sensor and it therefore amplifies both signal AND noise as well as adding its own noise (noise introduced by the amplifier stage itself). Changing ISO increases sensitivity to both signal and noise. Shooting to the right increases signal only. I believe this is actually a moot point though, as your computer screen is probably lacks sensitivity to see the difference unless you are brightening the image and doing some serious pixel peeping.

When you will not be postprocessing your images

Consider shooting at high resolutions in low light only if you actually need high resolution images. Strange as it may seem, shooting 6Mb images with a 12Mb camera (for example) results in less noise in the out-of-camera images (your camera is effectively using larger photosites in its sensor, reducing the effects of noise significantly). Something to bear in mind if you are taking ‘night out’ type images destined for social websites and 6×4 printed snaps only.

Better still, avoid shooting-right unless the image allows it (i.e. shoot a brighter image only if a brighter image is acceptable). Otherwise simply shoot for the key tones (or put another way; you don’t want to fill your image with data, you want your image to display your main subject accurately), and if that causes noise problems, get more sensitive camera equipment!

When you are shooting High ISO close to your camera’s limits

There is potentially one big edge case when shooting to the right makes a lot of sense: when you are shooting at a very high ISO because there is very little available light. Under these conditions, a number of things occur:

  • You are at a high ISO (typically 1600 or higher) and the amount of noise makes your shots borderline usable especially because noise is now visible in the midtones and even highlights. Under these conditions, you may quite rightly consider trading color accuracy for less noise.
  • The histogram has a large gap to the right because you are in low light conditions.
  • There are no highlights in your image because of the low light conditions.
ISO 12800 vs ISO12800 shot to the right
ISO 12800 vs ISO12800 shot to the right

Consider the two images above. The image to the left was shot at ISO12800,at 1/125s shutter and f4.5. The image to the right is identical except it was shot with an exposure compensation of 1.3eV, a value that was chosen as it pushed the histogram up to the right edge without going over (it also decreased the shutter speed to 1/50s). I then decreased the exposure of the rightmost image by 1.3eV in post processing. I have not done anything else to either image.

What has happened? Well, the left image has better color (the surface the pen is sitting on is white, but looks bluish in the shot-right image), but the image to the right has much less noise and is actually usable, which cannot be said of the left one irrespective of color accuracy! So shooting to the right under high ISO conditions has saved us from an unusable shot by reducing noise considerably, but at the expense of color accuracy. I’d call that a good trade-off!

Why not just increase ISO for the second shot and then you don’t have to bother exposing down? Well, ISO and exposure compensation work differently. Increasing ISO amplifies everything.It gives you more signal, but it also amplifies the noise (as well as adding some amplifier noise for good measure). Increasing exposure compensation allows more light to the sensor by changing shutter speed or aperture (in our image, it left the shutter open longer). As long as the shutter is still fast enough to prevent camera shake and you don’t blow highlights, exposure compensation is better (and certainly looks visibly better) than a higher ISO, because the former increases light to the sensor and therefore increases signal only.

The rightmost image looks better, so why don’t cameras do this exposure compensation trick automatically? Because camera manufacturors are very conservative and don’t want to blow highlights. Even though you are in low light, your image may still contain spots of bright highlights (night sky stars or stage lighting at an otherwise dark rock concert venue for example), and the camera is trying to preserve them but is not clever enough to realise when your scene doesn’t contain any, so it doesn’t mess about with exposure compensation even when the opportunity arises.

Although noise will always reduce if you shoot right via exposure compensation, its worth noting that the practice will always reduce color accuracy. There is a trade-off between noise and color accuracy, and this typically occurs at high ISOs (ISO 1600 and above), where the reduction of noise is worth the reduction in color accuracy.

It’s also worth noting that cameras equiped with image stabilisation will prevent camera shake when using  exposure compensaiton at high ISOs. For example, Sony cameras tend to have poorer high ISO noise, but Sony DSLRs also have in-camera stabilisation as standard. Using image stabilisation in conjunction with exposing right at high ISO can give Sony users results comparable with Canon/Nikon cameras at high ISO.

Carefully reading the histogram and knowing how ISO and exposure compensation both work can produce better results than the camera default in low light (i.e just increase ISO) as long as you know how to read the scene and expose for noise rather than highlights when the opportunity arises.

When you are shooting AVCHD video

This section added November 2013: adds extra information relating to video enabled DSLRs.

There is one very good reason to always shoot right: when you are shooting AVCHD video. AVCHD compression splits the scene into lots of 16×16 blocks and saves each block with a different compression based on how important it is to the overall frame. Think of it as splitting the image into lots of little JPEGS, each with a different quality.

The ‘how important it is to the overall frame’ bit is partly based on how dark the 16×16 block is (it also depends on how many color variations the 16×16 block contains, so nearly solid color is deemed less important). Thus, shadows get the most compression, and appear blocky if you expose them up in post (an effect called ‘macro blocking’). By exposing to the right when shooting AVCHD, you give the compressor less opportunities to over-compress shadows and give you macro blocking. It also helps with uniformly lit skin (which may macro block because the compressor encoded it as a solid color). See also this post for more tricks and tips when working with AVCHD.

Examples

Here’s an image with a dark overall key and subdued highlights.  Overexposing (or for that matter, using a flash) would lose the gold and blue hues I’m trying to capture, leaving me with a yellow shell. Instead, I actually underexposed the image because that is the only way I can be sure of capturing the subtle coloring on the shell.

Snail hibernating in a clump of leaves

Here’s the histogram for the same image.

Histogram for the above image

Although this histogram tells me that less than 50% of the image data contains anything other than zeroes, I couldn’t care less. By shooting for my key colors, I capture the image I set out to create. Sure, there’s a low amount of information in the dark areas, but my eye can’t see into the dark; perceptually it doesn’t matter.

I re-took the image, this time shot to the right. I then tried to get the same effect as the original in post by digitally underexposing. This is as close as I get;

Same image, shot to the right, then processed back to the left.
Same image, shot to the right, then processed back to the left.

The wonderful and subtle gold has gone, to be replaced by metalic yellow (of the type used on packaging to fake gold – yuck), and the earthy blue-black becomes a more detailed but less compelling brown.

I don’t know about you, but I prefer the first image!

Conclusion

Shooting right is useful if your key tones are low key AND you will be post processing later to bring parts of the key higher. Shooting to the right helps you in this case because it adds more information for you to open up in post processing. Color should not be an issue in this case as the image will be largely tonal anyway.

Shooting to the right is also very useful in low light, high ISO conditions. If you can read the scene well enough, there are opportunities for forming an ISO, exposure compensation and shutter combination that will reduce noise much more aggressively than your camera could (or rather would dare) to do if left to its own settings.

Thomas Knoll is recommending shooting-right because he’s assuming your going to be using Photoshop afterward. Although you can’t perceive the extra information, post processing may bring out the enhanced detail associated with the extra information as you open up certain tonal ranges.

If you will not be processing your images after shooting and your images are within normal ISO ranges (50-400), shooting right has little effect. The data is stored in the RAW file in a form suited to the needs of your eye and you can forget the underlying data structure. You are not ‘losing any data’ by not shooting right. Concentrate instead on your composition and key.

Notes

  1. When shooting in RAW, the histogram can be misleading because it is sampled from a JPEG representation. The RAW file has better dynamic range (about 1/3 to a whole of a stop at the top end). I’ve ignored that complication but accounting for it could in theory add more information to your RAW file. I say ‘in theory’, but I’m sure nobody would rely on that theory when shooting at a wedding, because  in practice, that blown out wedding dress may cost you significantly…
  2. I am shooting with a Sony Alpha a500. Certain makes of cameras may produce a worse/better result, but the issue will certainly exist with most cameras.
  3. The effects of shooting right at high ISO, and the resulting loss of color accuracy is mitigated somewhat by the fact that all cameras tend to lose color acuracy at high ISO anyway (noise has a random color, and this reduces overall color accuracy for your scene if noise dominates – i.e. at high ISO).
  4. Anyone wishing to explore the concept ‘Shooting for the key tones’ (a far better exposure policy than shooting-right in my opinion) is directed at Perfect Exposure by Micheal Freeman. You can see the promo for this book on YouTube here (link opens YouTube in new window/tab).