Photographing R/C Models
In this article I'll describe some key points in photographing model aircraft, including camera choice and shooting technique. All of the techniques described have been developed over many years of shooting models for the photo gallery.
Choice of camera
Shooting a model is easy enough when isn't moving. However the task becomes a whole lot more difficult when the model is in the air. The model
- may be moving fast
- may be dark compared to the sky
- may be a long distance away
- optical viewfinder, so no lag
- larger sensor with higher dynamic range, i.e. the ability to capture a wide range of tones e.g. a dark model against a bright sky.
- more flexible exposure controls allow blurring of backgrounds and freezing of action
- quicker focussing
- better sharpness
- less 'noise' in poor light
How many megapixels?
Cameras tend to be priced according to the number of pixels recorded by the sensor. In theory the more megapixels, the greater the detail which can be reproduced. In practice anything above around 12MP is more then enough for both printing and display.
Extra megapixels may be useful if you crop your images, but you'll need a pretty good lens to avoid loss of sharpness.
Composition and lighting are the two most important elements of a decent shot.
As regards composition, here's a check list. It sounds mechanical, but it's a start. The more critically you look at your images, the sooner you'll find yourself applying these rules subconsciously.
Tip #1 Fill the frame. Use a telephoto or else move closer to the subject. If this isn't enough then crop the photo afterwards.
Tip #2 Don't be Vlad the Impaler Look out for fenceposts braining your subject. Alter your viewpoint if necessary.
Tip #3 Lead the eye. The eye tends to follow converging lines, and is also attracted to bright areas. Bear this in mind when you frame the shot.
TIp #4 Avoid distracting highlights near the edges of the frame. When framing a shot, try and get into the habit of looking all around the frame for distractions, especially areas of brightness round the edges.
Tip #5 Use the "Rule of Thirds". The rule of thirds is a useful rule for landscape shots. Some cameras even show the thirds grid in the viewfinder.
Tip #6 Leave space to move into. When photographing flying models, leave more space in front of the model than behind. This will produce a more dynamic image.
Detail is what brings a picture alive! Detail is: the fluffiness in a bright cumulous cloud, or the panel lines on the dark underside of a wing. In order to capture detail, correct exposure is vital.
So what do we mean by'correct exposure? Essentially it means that the range of tones in the captured image should all lie within the dynamic range of the sensor. Put another way, there should be little or no solid blacks or saturated whites in the captured image.
Unfortunately the camera's metering has its limitations, and even with the best cameras, you can't guarantee a perfect exposure every time. Which is where the histogram is your friend.
Enter the Histogram
The histogram is an essential aid for obtaining correct exposure and virtually all cameras and editing packages offer this facility.
The histogram shows the distribution of brightness of the pixels in the image. Most importantly, the histogram tells you if there are areas of over- or under-exposure.
The horizontal axis represents brightness levels ranging from pure black at the LH end to pure white at the RH end. The number of pixels at each brightness level is represented by the height of the histogram.
The presence of a spike at either end indicates solid blacks or solid whites. These areas contain zero colour information. No amount of tweaking with a photo editing package can ever retrieve any colour or texture from areas captured as solid white or black.
Here are a few examples of a histogram (from my camera):
If the histogram indicates under- or over-exposure, then use the exposure compensation feature to increase or decrease the exposure relative to the camera's automatic metering, and re-take the scene. This may mean glancing at the histogram between shots, but it's a price worth paying especially while you're getting familiar with a new camera.
High contrast scenes
There are times when there is so much contrast within the scene that it's impossible to avoid a spike at either end of the histogram. Or to put it another way, the dynamic range of the scene is greater than that of the sensor. Typically this can happen on a very bright day with bright, directly lit objects accompanied by deep shadows.
Under these circumstances, obtaining detail in both the highlights and shadows is impossible, and compromise is necessary. Usually, we sacrifice shadow detail while allowing the highlights to roll off gently. This is OK because human eyes are are less sensitive to shadow detail than highlight.
Sometimes however, shadow detail is crucial to the shot, e.g. if taking a photo of a R/C installation. In this case, it may be better to 'blow' the highlights which are not part of the main subject. This where the judgement and experience of the photographer comes into play.
Another method which I mention in passing is High Dynamic Range (HDR) photography. In HDR, multiple images of the identical scene are recorded, each with a different exposure. The different frames are combined into a single 'HDR' image, thus compressing the very wide tonal range. For obvious reasons, this isn't practical a practical method for moving objects, so we won't look at it further. (Don't confuse proper HDR with the 'HDR-effect' filters provided in some cameras.).
With older dSLR's, you can only view the histogram after the image has been captured. However with point and shoot cameras and dSLR cameras with 'live view', the histogram can be used to check the scene before capture, so the photographer can alter the exposure settings before capturing the scene.
If you're not familiar with the operation of the histogram, do take a look at your camera's manual.
Lighting the Scene
Light is the second crucial ingredient. A small change in the light can have a profound affect on the scene.
- Overcast light is easiest to meter for.
- If it's a sunny day, then early morning and late afternoon are best.
- The most difficult lighting is midday sun, because of the combination of deep shadows and bright highlights.
Let's move on to some specific techniques.
Exposure systems are stoopid! Yes, really.
Your camera's metering system is pretty simple in the way that it treats an evenly lit scene: it tries to make all tones a neutral grey. So a shot of just bright white clouds will come out darker. A sheet of dark grey or black paper, will come out mid-grey. The camera, being dumb, doesn't know that the cloud should really be brighter, or that the black sheet of paper should be darker.
Consequently, you the photographer will have to intervene and adjust the exposure yourself!
Shooting a model against the sky
The classic problem is the "model-against-sky" shot . This photo of Andy Blackburn's Mig shows the issue - there's very little detail in the model, because the meter is being overly influenced by the much larger expanse of bright sky. The metering has rendered the sky as a mid-tone, leaving the plane almost in shadow.
There are various techniques to deal with this. The first, and the one I use, is simply to add +1.5 or +2 EV exposure compensation via the dedicated button on my camera. The camera will say to itself "there's lots of bright sky. Usually I'd make it grey... but the user has asked me to brighten it". The extra brightness will not only make the sky more realistic, but also show some extra detail under the wing.
Be careful not to dial too much compensation though, otherwise you'll end up with the opposite problem - part or all of the sky will end up pure white and all detail in the clouds will be lost. Most cameras have a highlight warning feature which indicates which parts of the image are 'blown'. Use the highlight warning and the histogram together. The histogram tells you if the image is overexposed, the highlight warning tells you where.
A variation of this technique is to point the camera at the brightest area of the sky, then add around +1.5 EV exposure compensation, and then lock the exposure (using the Exposure Lock facility on your dSLR). Then refocus on the model and shoot. By adding +1.5 EV, we push the camera into recording more light from the sky, just as in the last example. However, because the exposure is locked, it works well where the model almost fills the frame. However because the exposure is locked, and because the model is moving, this method is only practical if the sky is evenly bright. If the light varies across the sky, then the previous method is better.
The third method is a bit of a copout but is the most reliable - just wait for a nice blue sky and shoot with the light casting directly on the model. The sky will form a less contrasty background. This photo (right) shows the same model taken later that day.
Before we leave the subject, a quick word about post processing. To retain detail in both the sky and the subject, try playing with the contrast adjustment in your photo editing package. Contrast is basically the separation of adjacent tones, the more contrast in a particular tonal range the more detail you can see in those tones. Often, reducing the mid-tone contrast will provide better results. Why? Because reducing mid-tone contrast paradoxically increases the shadow and highlight contrast (something the magazines don't often tell you!). A detailed treatment of constrast management is outside the scope of this article, instead I strongly recommend the excellent tuturials at Cambridge in Colour (see link at end).
Lighting for people
In the shot on Mark Southall (left), the slanting evening sun has caught the folds in Mark's clothing. Note how the gentle light has allowed some detail to be retained in the shadows.
Lighting for objects
The shot of a Multiplex Evo RF module (left) shows the result. Notice the detail in the shadows.
P, Av, Tv... what mode to use?
All dSLR's come with at least three basic shooting modes: P (program), Tv(shutter priority), Av(aperture priority), and M (manual). In addition many dSLR's have special scene modes like Landscape, Portrait, Action etc.
For shooting models in flight, I use either Av or Tv mode, forcing a fast shutter speed. I also the focus mode to 'continuous' so focus follows the model.
For portraits I use Av mode and a large aperture (small F-number) to isolate the subject by blurring the background.
Polarising filters are useful for gettign those lovely deep blue skies. The only downside is that they soak up about 1 - 2 EV of light. You therefore have to slow the shutter speed, or choose a wider aperture, which makes them less suitable for flying shots. However they are a great way to add some bite to skies in static scenes.
The shot on the right of Frank Hulton's 'Falcon' was taken using a Hoya circular polarising filter (cost ~£15).
Nowadays a similar effect can be achieved in some editing packages - the tool is usually called 'vibrance' (a more refined version of 'saturation' adjustment, because it affects some colours more than others).
More Shooting Technique
The first job is to choose a suitable location for the shot, normally one or other side of the slope - depending on the light.
Here, Andy Ellison (standing on the left) is flying his Mach 1. What it doesn't show is the rather loud communication going on as I tried to get both the model and Andy in the frame. Andy had to fly several passes before we got the shot.
To help reduce the effects of camera shake, or when following a fast moving model, consider increasing the ISO setting to 400 or 800. Increasing the ISO setting effectively increases the sensor's sensitivity, thus allowing a shorter shutter speed to be used.
Each doubling of ISO allows the shutter speed to be halved, so a shutter speed of 1/60th at ISO 200 becomes a much faster 1/250th at ISO 800. This can make the difference between a blurred and an acceptable shot.
There's no such thing as a free lunch of course, and the price is increased image noise. Normally for a dSLR, ISO 800 is a reasonable limit. With a point and shoot camera, anything above ISO 200 may show unacceptable noise.
Post processing: RAW format, JPEG's and editing
I find it very rare that an image does not benefit from some post processing. In fact some post processing is usually essential to produce a really good image, irrespective of how expensive the camera is.
The three main tasks are:
- Optimise the tonal response of the image (contrast/brightness)
- Remove colour casts
No need to go to the expense of Photoshop though, Google's Picasa is a useful image editor and organiser which also happens to be free. See links below.
For ultimate quality, advanced photographers will set their camera for RAW capture.
RAW images contain just the raw brightness levels recorded by the sensor. They don't take into account the characteristics of the colour filters which overlay the sensor. Consequently, an extra step is required to convert the raw data to RGB (e.g. JPEG) images. This step is performed using a 'raw converter', and most raw converters provide the photographer with a great deal of control e.g. the ability to retrospectively alter the white balance, brightness, contrast, hue and saturation.
I hope this has stimulated you to take a camera to the slope and start shooting. I promise it will add some extra fun to your flying sessions!
- My guide to choosing a camera.
- My gallery on Flickr
- Kevin Newton's cool site, has lots of great R/C glider images.
- Cambridge in Colour - an excellent digital tutorial
- For camera reviews go to DP Review.
- For ordering prints online, Photobox is great. Good quality, fast service and cheap.
- Excellent free image editor and web storage: Google Picasa