Have you ever wished your vacation photos looked a bit sharper or wondered why your nose looks big in a selfie?
Two scientists from the University of Surrey, England, embarked on a mission to help us get the most out of our digital cameras.
These devices, with their automated and computerized components, represent the technical pinnacle of photography in its 200-year history. And every year more advanced and cheaper technology hits the market.
«But it is still remarkably easy to take a bad photo,» Radu Sporea tells the BBC.
Sporea and his colleague, Andrew Pye, go out of their way to explain some of the principles that give photographs a touch of class.
Perspective: the selfie problem
A key step that is often missed, Dr. Sporea tells me, is to think about where the photo is being taken.
Using a normal digital camera, with a wide angle lens, placed very close to the object – say, an arm’s length away – is going to distort the object in question.
If it is a portrait, the face (yours or someone else’s) may appear slightly protruding, with a large nose and ears that fade.
So to avoid taking a photo that looks like the famous monkey in the selfie, taking a step back can make a difference.
Obviously, this is not very useful for a quick self portrait. But distance yourself and then do zoom, so that the object still looks nice and big, it produces a ‘foreshortening effect’ that makes everything appear glued and similar in size.
Even if it is not a portrait, this foreshortening effect can create interesting effects, particularly if the objects in the photo are at different distances.
«The way we move around the subject is important,» says Sporea. «What people do sometimes is just stay stationary and zoom. But doing this and moving physically is not the same.»
Perspective is also the kind of trick to be reckoned with when the only thing at hand is your smartphone’s camera.
However, Sporea and Pye are skeptical about the possibility of taking really spectacular photos with phones.
«You can’t do anything because the phone’s camera is completely automatic,» says Sporea.
But you can add some life to the image by completely contradicting the instructions I just described for taking a portrait and getting very close, which can work for food or natural landscapes.
«Because the lens is very small and the sensor is very small, you really have to be very close to achieve some kind of separation.»
Exposure: time is of the essence
The photograph is created when light hits the sensor. Once upon a time there were sensors that were nothing more than a strip of film: if there was too much or too little light, the photo was useless and had to be thrown away.
Digital technology means that we can retake the photo without wasting the film. However, getting the right amount of light to the electronic sensor – controlling exposure – is still critical.
Most of us are familiar with the «washed out» and bleak result of over and underexposed photos, respectively.
The most obvious way to control the exposure is to change the time of the exposure in question, with the shutter speed control.
Automatic cameras adjust this automatically, but it’s worth figuring out how to intervene.
A digital camera also allows you to manipulate its sensitivity directly (something that is often listed as ISO in camera settings), which can be useful for enhancing the photo if the scene is very dark.
Sporea warns of the dangers of manually manipulating the ISO.
«This is not a physical control. You are electronically amplifying what is happening,» he says. «And this has its consequences.»
If the sensitivity is maximized to detect extremely low levels of light, for example, the tiny amount of light striking the sensor is drowned out by electrical noise within the chip. Amplifying everything produces speckled images.
«So – basically – it’s better to use the ISO as a last resort.»
Opening: expand your options
Another way to control how much light enters the camera is by changing how much the lens uses, enlarging or reducing the «aperture».
This produces other effects besides changing the brightness of the photo; some that can be very useful to play with the way the image looks.
If the aperture is very small, there is almost no limit to what can be focused on within a single shot. Light coming from any distance can be clearly focused on the sensor, because the distances involved are much larger than the extent of the lens used.
This is why everything appears in focus when using a pinhole camera.
Photographers call this property «depth of field». And using a much wider aperture flattens the scene much more, so that only the area you choose will appear in focus, and the rest will be blurred.
Sometimes this produces fantastic photos, professional and atmospheric.
«If you’re shooting portraits, you want a shallow depth of field, so only the subject appears in focus,» says Sporea.
So, in this situation, Sporea recommends choosing a large aperture (which, contrary to what you might think, in a digital camera is represented by the smallest number, since the value is the denominator of a fraction).
«But if you’re shooting a landscape, you want as much depth in the scene as possible to appear in focus. So reduce the aperture.»
Lighting: soft is better
One last tip from Sporea and Pye relates to how the scene is lit, if you have the option to manipulate this element.
In particular, in addition to thinking about the direction of the light (for example, to avoid backlit silhouettes), the quality of the light itself can make a big difference.
«If you have a small light source – including the Sun: it is large but far away, so it appears as a point – the shadows are very pronounced. There is a clear separation between the light and the shadow,» explains Sporea.
«In short, avoid photos at noon or in very strong light.»
Covering that light with a shade or an umbrella, or bouncing it off to another surface, produces a lighter light source and less prominent shadows.
This does not require expensive equipment, emphasizes Sporea, who points out that even fashion photographers improvise with sunlight reflected off road signs.
Experiment to win
In short, the recommendations of these scientists – none of whom study light or lenses – boil down to trying different things.
«Don’t worry about the camera you have; that’s not what makes good photos,» says Sporea. Just experiment with any digital camera that allows you to play around with some of these settings.
In particular, he advises having the courage to leave the «automatic» mode.
«It is not always reliable.»
Instead, he suggests trying a «semi-automatic» mode. Many cameras have it, allowing you to control the shutter speed or aperture, while the rest is adjusted by the machine.
With this starting point, the lesson ends.