become a better photographer

Digital cameras have one very interesting advantage over good old film cameras: you can adjust settings that you would normally have adjusted by changing film. An obvious one is the ISO setting: one shot can be taken at 100 ASA, the next one at 400. A less obvious but very important setting is the white balance. This setting is meant to adjust the colour balance in different types of light so that white areas actually come out white. If you get the white balance wrong, the white areas in your shot will come out yellow or blue, depending which way you got it wrong.

Most DSLR cameras and some high end compact digital ones allow you to override the white balance, typically by offering a presets for tungsten or fluorescent light, cloudy or shade conditions, etc. But your specific lighting conditions don’t always match a preset. Some cameras allow you to provide a sun temperature equivalent in Kelvin but this is confusing if you are not an astronomer or a physicist. Finally some cameras allow you to specify a custom white balance by giving them a reference. I had never used this setting as I wasn’t too sure how it worked on my camera, until today when I picked up a copy of Mac User that has a very simple and straightforward explanation.

I decided that the subject for experimentation would be my bedroom, complete with unmade bed. Not that I want to pretend I am Tracey Emin but the wall behind my bed is the best white reference in my flat. To make my life easier, I composed the shot to ensure a large area of white wall would cover the centre of the image, as this is the area the camera will use as white reference.

• The first picture is taken using the automatic white balance setting. Although the camera tried to compensate for the yellow hue produced by the tungsten light, it is still very yellow.
• The second picture is taken with a preset white balance for tungsten light, which should be the right setting in this case. unfortunately, and probably because of the lamp shade that modifies the light, it is still quite yellow. Although, in this case, when seen on its own and in the original light, the mind adjusts and makes you think it is actually white.
• The last picture was taken using the custom white balance seting and the previous picture as a reference. This time it is really white: I verified this by using the colour picker tool in Photoshop. The funny thing though is that seeing the shot on the camera’s LCD screen, on its own and just after the previous one, the mind plays tricks again and makes you think it is blue-ish.

Using a custom white balance produces great results. The only complication is that you have to take a reference shot and adjust the setting every time you change light condition but it is easier and quicker than doing that in Photoshop afterwards, especially if you take several shots in the same lighting conditions. Also note that, because it consists in comparing the balance of primary colours in a reference subject, this reference doesn’t have to be pure white, it can be light grey. So a photographic 18% grey card is an ideal reference object.

One typical photographic trick to draw the viewer’s attention to the subject is to use a shallow depth of field so that the main subject is sharp while the rest of the picture is blurry.

The main parameter that drives the depth of field is the aperture, that is how wide the diaphragm in the lens is open. The lower the aperture value, the wider the diaphragm and the shallower the depth of field; the higher the aperture, the narrower the diaphragm and the deeper the depth of field.

A secondary parameter is the focal length of the lens: the longer the focal length, the shallower the depth of field. At the same aperture setting, a telephoto lens will produce a shallower depth of field than a wide angle lens. This is one of the reasons why landscapes come out better with a wide angle lens and portraits come out better with a telephoto one: a wide angle lens will allow you to have everything in the picture very sharp while a telephoto lens will allow you to have your subject sharp while the surroundings are blurry.

In this picture, I used a focal length of 400mm and an aperture setting of f/5.6. With my camera, a focal length of 50mm has an angle of view equivalent to the human eye so 400mm is a very long focal length: we’re getting into papparazzi territory here. An aperture of f/5.6 is as wide open as can be with this lens. So the result is a very shallow depth of field.

Sometimes you just can’t resist: you have perfect photograph material staring at you. I was at a party at a friend’s on Sunday and she had those tired sunflowers against the wall. Even though they were past their prime, the white wall behind made them stand out in amazing fashion. Sunflowers are great. No wonder Vincent van Gogh loved them.

I have the ideal experimentation ground for macro photography just across the bridge from where I live: the Royal Botanic Gardens at Kew, also known as Kew Gardens. I went today and experimented.

To take extreme close-ups, you need a macro lens, a lens that has a very short minimum focussing distance, thus enabling you to get very, very close. At such a short distance, the depth of field is very shallow: you have to focus manually and set your camera on a very narrow aperture, thus requiring a longer exposure. All this means that the most important factor when taking macro shots is to ensure that your camera and your subject are absolutely still. So, after the macro lens, the most important piece of equipment for macro photography is a tripod.

Once you’re all set, you just need a good pair of eyes to spot the little details that can make a great picture. Nature is absolutely wonderful at creating fantastic minute structures in the most unexpected ways.

The typical trap for a photographer who is in a place where there are a lot of interesting things to capture is to want to capture everything in one go. Sometimes it can work but often it just produces a cluttered picture with no central subject. There is also the danger that the exposition will be correct for only part of the picture.

Reducing the field of vision and capturing only part of a scene, focusing on a single subject can make a much stronger shot. It can also transport the viewer to a completely different place by removing a lot of the context. For instance, if I were to ask where was this picture taken, what would be your first guess?

One of the good things about being in Atlanta at the moment is that I am working and going out with people who are as passionate about photography as I am and from whom I can learn. So the past few days have been quite busy, as I took 800 shots. Yes, eight hundred. There is a lot of garbage in all this but it is garbage I can learn from and that I can delete by pressing a button. This is the beauty of digital photography: you can keep shooting as long as you have room on the media card, it doesn’t cost you anything and you can throw away the bad stuff afterwards.

But still: 800! Why? Because I was shooting moving targets. The best way to explain is to go over the week-end’s activities:

Friday evening: we went to a basketball game at Wesleyan high school. We were cheering the home team. I learnt quite a few things:

• Basketball is a very fast game. I didn’t realise how fast until I saw it and tried to photograph it. It is impossible to get a good action shot by just waiting for it because whatever is interesting is usually finished before you have the time to even think about pressing the shutter release. The only way is to shoot continually while following whoever is in possession of the ball. Out of a burst of 10 pictures, one might be good and the rest can be deleted. There is a lot of garbage but you would not be able to take that good one if you weren’t taking the other 9 bad ones.

• The better you understand the game, the better you will be able to predict where the action happens.

• When shooting with a Canon EOS 5D in continuous shooting mode, with AI Servo focusing, keep your subject in the centre of the frame so that the centre focusing point is used. This is the most sensitive focusing point and will be the one favoured by the camera in AI Servo, because it has no time to really use the other ones. It might mean the composition of the shot is boring but you can always crop later and anyway you have no way to think about composition when shooting basketball.

• When using the panning technique with an image stabilised lens, don’t forget to switch the lens to one way stabilisation so that it doesn’t try to counter the panning movement.

Saturday: we went to Callaway Gardens, where we saw a bird of prey show and the exotic butterfly greenhouse. There I learnt:

• When shooting big birds, make sure you have your camera on a high ISO setting, even if you are immobile and even have a tripod. You need a very high shutter speed, not because of your own movement but because of the bird’s movement: an eagle can flap its wings and accelerate much faster than you think so if you want to freeze the bird’s movement, you camera has to be even faster.

• When shooting butterflies, a long telephoto lens can do as good a job as a macro lens. A macro lens is great to enable you go get very close to your subject and photograph small insects. However, butterflies are extremely fast and will disappear before you can focus on them. A good telephoto lens with fast focusing will enable you to take the shot from further away so that you don’t frighten the butterfly or you can take the picture before it flies off.

• Don’t even think of trying to follow a flying butterfly with your camera and take continuous pictures, the same way you’d do with a basketball player. Butterflies are much less predictable and much faster, even though you might think the opposite when at a basketball game.

Monday evening: we went to another basketball game at Norcross high school. We were cheering the visiting team. I learnt:

• There exists a game faster than basketball: basketball played by a winning team that are getting increasingly nervous at seeing their opponents come back on the score board and are trying to score as many points as possible in the shortest amount of time to rebuild their safety margin.

• If you are shooting using the panning technique with an image stabilised lens, do switch it to one way stabilisation. Really, I mean it.

• When using AI Servo focusing, start with a full battery or have a spare one. AI Servo does consume a lot of battery power as the camera is constantly re-focusing.

I’ve had a lot of fun during this week-end and have learnt a lot about taking pictures of fast moving targets like sports or animals. I think it has made me a better photographer but there is certainly room for improvement.