If you're a newcomer to photography, or taking portraits, you may not be aware that the lens you use can drastically effect the outcome of your images. Here, we explain a bit more about lens perspective and angle of view, to help you decide what's best for what you want to achieve.
Wide angle lens, 18mm
Medium focal length, 70mm
Long focal length, 210mm
Angle Of View
Angle of view is basically how much of a scene can be seen through the lens. So for example, a fisheye lens, which is usually 15mm, will capture more of the scene than even your own eyes can see, whereas a 200mm lens at full telephoto will only capture a very small portion of the scene when zoomed in.
If you're looking for a view equivalent to what the eye can see, a 50mm lens or around that number will be the best choice. Above is a 70mm shot that looks pretty natural.
Positioning of your model can also play a part in how your photos will turn out. For example, if you want to include lots of background in your shot but still keep the focus on the model, then using a wider angle lens will work, as long as you make sure that the subject is standing close to the camera whilst the background is some way away. This is shown in the 18mm shot above. The model is the main focus, but you can also see a lot of the background relatively clearly too.
If you'd prefer to only have a small amount of background in the shot, then a telephoto lens is the way to go as it will isolate the subject more, as you can see in the 210mm shot above, where the background is nicely blurred.
The focal length of the lens you use will also have a big effect on perspective. Perspective gets compressed the larger the focal length you use, so if you want to add a sense of depth to your photos then a lens around 50-100mm will work well. Any longer than 100mm and the background will appear closer to the model, compressing the perspective.
The smaller the focal length of the lens, the more of the scene you will fit in. For example using a fisheye lens will enable you to get pretty much all of the surroundings in when shooting. You'll be able to see all of the background relatively clearly. The longer the focal length the more the surroundings are cut out, until you're only able to capture the model and a little bit of the surroundings.
The image will also look pretty distorted if you use a smaller focal length, such as a fisheye. These will create a curved effect around the edges, and make the model look out of proportion.
This is a good effect if you want something more surreal, but is not very useful if you want a natural looking shot. As said earlier, the best focal length for natural shots is around 50-100mm. Any longer than this and the perspective compression may make your model look a little flat. As you can see above, the longer focal length blurs out the background and leaves focus purely on the model.
Sometimes the only way to find out what will work best for you is to experiment. Take a couple of lenses out with you and see what works best with what you want to achieve. Take a look at the review section on Totally Tamron
for more lens advice then head over to the Tamron
website where detailed information about their lens range is available.