Saturday, 23 March 2013

Aircraft at night: post-processing

Fig. 1. Armee de l'Air Alpha Jet at RAF Northolt, March 2013
I have previously blogged about taking pictures of aircraft after dark. I went on another night shoot at Northolt last Thursday evening, and thought I would use a picture from that session as a follow-up to my previous blog piece, turning this time to my approach to post-processing.

Parenthetically, I won't put too many pictures from that session here: if you are interested, the set is on Flickr.

The picture at the top of this post (Figure 1) is one that seems to have gone down quite well on Flickr. It shows a French Alpha Jet: notice the pilot's helmet hanging on the side by the cockpit. I'll talk you through my approach to postprocessing this image using Lightroom.
Fig. 2. Original of the image shown in Fig. 1.
Here is the original image, without any alterations (figure 2). It looks pretty ghastly. The night sky looks like West London is some kind of hellish inferno, and the overall contrast is rather low. It was shot with my 18-70 mm lens on the D300, with the zoom was at its longest setting (70 mm). Because I couldn't get any closer, the framing is loose, but it gives me the opportunity to crop to the shape I like, and , in any case, gives a sense that the aircraft can move in the frame. The horizon is – of course! – a little Wonky; however, that's easy enough to correct.

The good thing though is that the exposure on the aircraft itself is pretty much correct. Nevertheless, you'll also notice the nature of the exposure. It looks hugely overexposed, with nearly burnt out foreground, and sky that is way too bright for the night. But the reason is exposed like this is to get light from the shadows under the aircraft.
Fig. 3. The histogram for the original image.
The histogram (Fig. 3) is very ugly, but it shows that I have chosen an exposure that retains data all the way across the brightness range: neither the blacks are blocked up, nor the highlights are badly blown (there is a tiny blip at the very highest exposure data point, but that is from the lights in the background, and there's nothing that can be done about them). So, odd as it may look the exposure was exactly the way I wanted: this is an example of the "expose-to-the-right" method. I might also point out that the exposure was 30 sec: there's really not that much light there, and the picture is way brighter than it looked to the eye.

Evaluating this picture, there are several things that need to be done. First of all, a decision has to be made about the crop: do we give the aircraft space to move, or do we crop in tight? Whatever, the horizon has to be levelled, there's a couple of distracting cars in the background that can go (I make no apology for that: those cars would drive away at some point anyhow). How about the white balance? The lighting is a mixture of sources, so we'll need to think about the overall balance put on the aircraft. And then there's the whole problem of the bright sky and foreground. The sky does not look the way I remember it – the long exposure has brought out all the lights of London glaring on the dusty sky, and at the very least that needs to be corrected. But more than that, the classical way that the eye moves across the picture is that it is drawn from dark to light. So I wanted to keep the aircraft comparatively light while darkening with the sky and the foreground to draw attention to the subject. The image is also quite low contrast, and adding a bit of Clarity should perk it up.
Fig. 4. Import preset applied, and cropped/levelled.
I have a preset that is applied during import into Lightroom: this applies +40 Clarity, +20 Vibrance, as well as some heavily masked capture sharpening, and the Camera Standard version 4 profile. The lens correction profile is also applied by this preset. Figure 4 shows the image after import with this preset applied and cropping plus levelling the horizon. It immediately looks a bit better. That preset is one I regard as my starting point for processing a picture to be modified as required, but in this case I think it works fine and clarity/vibrance don't need further adjustment.
Fig. 5. Sky and foreground darkened
Fig. 6. A little positive exposure painted on to the aircraft.

The next thing is to darken both foreground and the sky. This is done by applying negative exposure adjustments on gradient fills in Lightroom, and also painting in some negative exposure around the undercarriage. I added an additional small darkening vignette. The result is shown in Figure 5.

Having looked overexposed originally, the image now looks more or less fine, but if anything I would like to add some luminosity to the aircraft itself, again to make it pop into the viewers vision. Figure 6 shows the result of applying a positive exposure adjustment with a brush over the aircraft.

At this point, having got the overall look more or less the way I want it, we can look at the white balance. The problem with trying to adjust the white balance earlier is the strong effect of the sky on the image makes it difficult to evaluate what the final look should be. So I left it until this point to fine tune the white balance. The shot was taken on auto white balance and bearing in mind the nature of the mixed lighting it has done a remarkably good job. I've tried adjusting the white balance, but in the end I think I prefer it as shot.

The final step is to clone out the cars and a few tiny distractions in the background.  The picture at the top of page (Figure 1) shows the result.

Although this is a very particular example of my approach, the general philosophy for night shoots applies throughout. 1 – expose to the right. 2 – the eye moves from dark to light, so draw attention to the subject by darkening the area around it. 3 – think about the white balance: even though your camera probably does a very fine job in mixed lighting, it may not give you the results you want, so fine tune it to your taste.


  1. Anthony
    Another excellent aircraft shot, and at night.
    Your notes on post-processing are very helpful and informative. The image is very sharp. Although not part of post-processing I am interested about your method of focussing and depth of field; a] what depth of field did you use and b] the D300 and D700 both have 51 focus points available. How many did you use and if you used a single point where did you locate it on the aircraft?
    Many thanks.

  2. Hi Stuart,

    Thanks so much for your kind remarks. The EXIF says this was taken on AF-C, but I can't tell you any more than that about focusing. If I'd had it on AF-S, I'd have put a single point on the cockpit. EXIF also says f/8 for aperture, 30 sec exposure, ISO 200, +1.3 EV exposure compensation. I'd have chosen that because I know that f/8 would (a) give me sufficient depth of field at the distance I was away from the subject, and (b) I know from experience that the lens I was using (my old 18-70 mm kit lens) has really good performance at that aperture.

    All the best,