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I’m having a lot of difficulty understanding depth of field. Can you explain it more clearly? Peter, Seoul.

Depth of field (DoF) is difficult to explain without diagrams and charts. It’s more about math and physics than it is about photography. However, I can give you some starting information, which is enough for most photographers.

DoF, simply, is the distance between the nearest and farthest objects which appear to be in focus. This is quite a subjective concept, because it’s difficult to always define the focal range. Further, all photographers have different views regarding the use of DoF.

However, DoF is extremely important to photography and film.

Focal range is controlled by the camera’s aperture. A small aperture (eg f22) will have a very wide depth of field. A small DoF will result in large elements of the photograph appearing in focus. Conversely, a wide aperture (f2.8) will have a much smaller depth of field. As a result, the out of focus area will be quite big. Yes, it’s ironic that these concepts seem inverse (small aperture - wide DoF, wide aperture - small DoF).

When it comes to understanding what parts of the photo will be in focus, there’s a two thirds rule applied to DoF. One third of the area in front of the focal point will be in focus, but two thirds of the area behind the focal area will appear to be in focus. So it’s important to know that much more of the focal range is behind the focal point, not in front. It’s not evenly split (50/50) around the focal point.

There are a few other factors which can make the focal range either larger or smaller.

Firstly, as stated, small apertures give wider DoF.

Second, shorter lenses also create a wider DoF. A 50mm lens will give a much wider DoF than a 200mm lens, if the same aperture and settings are used.

Finally, the greater the shooting distance, the greater the depth of field. This one is logical really. If photographing mountains, DoF can be read in kilometers. If photographing bugs (macro photography) DoF is mere milimeters. So the further away your subject, the longer the DoF.

Generally, photographers have two approaches to controlling DoF. In most cases, photographers prefer short DoF and large areas which are out of focus. This helps control the viewer’s attention by blurring the foreground and background elements, while keeping the subject in perfect focus. Portrait photography is a good example of this. Most portrait photographers use longer lenses and wide apertures.

Small DoF also creates more ‘bokeh’ which is one of photography’s most important attributes.

However, there are many times when a wide DoF is desirable, such as in landscape photography. A good landscape photo should appear to have everything in focus, from mountains at the back to rocks in the foreground. This can be achieved with wide lenses, small apertures and focusing to infinity (which all cameras can do).

Those are the basics to depth of field. The important thing to remember is that DoF is easy to control because the aperture, lens length and focal length all play a simple part. Combine them well and you can be a master of controling DoF, producing great photos with very high impact.

Happy shooting!

David Smeaton

I’ve really started to enjoy photographing landscapes. Can you give me some tips to improve my landscape photography? Christina, Seoul.

Landscapes are great fun. Many travellers find themselves with lots of opportunities to photograph landscapes and nature. So it’s handy to have a couple of tricks up your sleeve to make the most of your shots.

Here are some handy hints for shooting landscapes.

1. Get up high - A high vantage point often gives you quite a commanding view and can create a sense of awe in your photos.

2. Shoot early or late - When taking photographs, it’s always best to shoot in the morning or late afternoon. This is particularly true for landscapes; colours are more natural and light is less harsh. Your photos will come out looking much better.

3. Reflections - Including water in your photo is a great trick to giving the shot an extra dimension. Use rivers, lakes, ponds or other water features to your advantage.

4. Tripods - Use a tripod when possible. This will give you a much more stable platform and more control over your camera settings. You can use longer shutter times and shoot in lower light.

5. Wide angle lens - Use the right lens for the job. A wide angle lens, somewhere between 10mm and 18mm, will give you much more distance and you can get a whole lot more in your frame.

6. Filters - A circular polarizing filter is your best friend to give your colours more punch. A ND filter can also reduce contrast and capture more details in your photo.

7. Focus - Use lower apertures, such as f16 or f22, to give your photograph much more depth. Focus on the foreground and your background will still appear to be in focus. In low light, you’ll need a tripod to
ensure your aperture (depth of field) is sufficiently low. If there’s an object in the foreground, such as rocks in a river, then use it as your main focal point. A foreground object helps frame the scene and give the image a more three dimensional appearance.

8. Framing - Control your frame and be aware of what elements you want to ‘frame out’ of your shot. Use the rule of thirds to include some sky or water in the foreground. Frame out unwanted trees, grass in the
foreground, or other distractions.

9. Be Patient - If you arrive at your location in the middle of the day, take a few shots, have lunch, or look around. Find some shade and rest until the sun has cooled off. You need to be prepared to wait for just the right conditions; otherwise your photos will never look their best. If you’ve made the effort to trek all the way out to a secluded spot, then at least put in the effort to get your photos right.

10. Experiment - Don’t be afraid to be creative. Try bracketing or similar techniques which you can use to create HDR photos. Another good trick is to use a slow shutter speed to blur water. Infrared landscapes are also very popular.

Happy shooting!

David Smeaton

i found this great lecture by sir ken robinson. he talks about schools and education, whether the current education system kills creativity. it’s really interesting and he’s quite funny. there are a lot of useful and valuable points made … as a drama teacher, i completely agree with much of what he says.

I’m thinking about buying a tripod, partly because I’ve been told that it’s a good idea. Do I really need one? - Mitch, Seoul.

Definitely! Anyone who’s serious about photography should own a tripod. The most simple reason is because shooting from a stable tripod is going to give you more ways to shoot. The biggest benefit of a tripod is longer exposures. It’s difficult to shoot slow shutterspeeds by hand. Once your shuttter speed gets down to 1/30 or lower, then it’s almost impossible to make your shot steady. One solution is to use a higher ISO, but then you trade off quality for speed. The other option is a tripod.

Buying a tripod is almost as difficult as buying a camera. There are a few important considerations: stability, leg joints, type of head and cost.

Stability is the most important. A cheap or flimsy tripod may move or sway under the weight of the camera. This makes the tripod useless in most situations because it’s no better than hand held photos. Each tripod is recommended for a certain weight. Make sure you get a tripod that can handle 8-10kg, which is good enough for most photographers.

Most tripods have 3 legs, obviously enough, but monopods are also popular amongst sports shooters. The most important consideration with legs is the number of joints. Commonly, tripods have either 3 or 4 joints. This equates to how high the tripod can be extended. 4 joint tripods are taller, but again there’s a trade off in terms of stability; the higher the tripod, the less stable it becomes. A three joint tripod is usually good enough. They can extend to about 150cm.

When considering legs, I recommend getting a tripod with independent legs (so that the legs can be moved separately). Some tripods have extra joints holding the legs together. Although this provides greater stability, it limits how far the legs can be spread and also limits the tripod’s flexibility on uneven ground.

The type of tripod head is another important issue. Amongst serious photographers, ball heads are by far the most popular because they allow the greatest mobility. Ball heads have fewer moving parts and are also lighter. However, just like tripod legs, check the rated weight limits of the tripod head. The head should be able to handle 10kg of weight. Otherwise it may not be stable enough.

The cost of a tripod is relative to quality. The more you spend, the better the tripod. However, big manufacturers do make budget tripods that are very good. The only real downside is that cheaper tripods can be heavier, due to less expensive construction materials. If you can afford it, buy carbon fiber tripods. They’re incredibly light and strong.

Most tripods have a neck column. Extending a tripod neck is a bad idea, because they’re always the most unstable part of the tripod. Good tripods have a hook under the neck column. The hook can be used to hang your camera bag (or other objects) to add weight to the tripod. Why would you do that? Because the weight gives the tripod further stability.

Buy yourself a good tripod and it’s a decision you won’t regret. You’ll also start to see amazing opportunities for photos that you never had before.

Happy shooting!

David Smeaton