In the game of definitions and descriptions, photographers can be a vague bunch, write Jon Adams and Andrew James. But when it comes to lenses and focal lengths, we have the opportunity to be fairly precise, because the focal lengths we use have specific numbers attached.
In traditional photo parlance – based on 35mm film cameras, we can start with ‘normal’ lenses – so called because they have approximately the same magnification as the human eye. If you set a focal length of 50mm on a zoom lens and keep both eyes open when looking though the viewfinder, you’ll see that this is the case. Anything with a focal length over 50mm is called a telephoto, because it’s increasing the eye’s magnification, and anything under that figure is called a wide-angle, because it’s reducing it, and giving you a wider view than the unaided eye.
That ‘normal’ number of 50mm has been a bit scrambled over the digital years, because although the magnification remains consistent, we now have different-sized sensors that require a crop factor to be applied. This varies from maker to maker, but 1.5x, 1.6x and 2x are the most common for APS-C and FourThirds formats.
With wide-angles, we have the fairly pedestrian wides of 24, 28 and 35mm that are often found on ‘kit’ lenses, and then we have the ‘ultra-wides’ which use an even lower magnification to pack a whole lot more into the frame. These take you down to around 16mm (10mm for APS-C users, and 7mm for 4/3rds), and are magnificent tools for landscape photography. But although their scope is tremendous, they have to be used with care, as they present a series of issues which can become a problem if you don’t know about them…
One obvious one is image distortion, where your verticals aren’t straight and even your horizons can be curved. You can get around these to some extent at the shooting stage by holding the camera higher and as level as possible, but you won’t necessarily lose all distortion – especially with extreme wides. What do you do? You either live with it and call it ‘style’ or you need to process it out. Both Lightroom and Camera Raw give you some post-processing options for raw files, and you can see see AJ’s video here.
Photoshop’s Transform cropping facility is certainly the most flexible and powerful option when it comes to removing this kind of distortion and you can watch Jon playing around with this here. If you are taking the post-processing option though, remember to shoot loose as you will lose some of what’s in the frame when working on the file.
The other main factor to think about is that when using a wide-angle lens, distant things get further away and what’s close by becomes more important. Compositionally this makes one hell of a difference. Put bluntly, you need foreground interest and also to consider whether you shoot with the camera held vertically in portrait format. Horizontal or rather ‘landscape’ for a landscape shot seems the most obvious thing to do, but actually, when it comes to wides, shooting upright can often be the best approach.
The photo above is a 16mm wide-angle shot, and there’s some foreground interest, plus a lead-in line that takes us up towards the boat. But in truth, it feels a little ‘windy’! That’s not the breeze blowing off the North Sea but the amount of space that’s not working hard enough in the foreground.
Same boat, same day, same focal length but a different position. Look how we’ve packed the interest into the foreground sand pattern and the anchor chain. It’s a much more successful shot, and we still have a lead-in line. To fill the foreground like this you have to get right over it with your camera and lens.
The big question is, when shooting with a wide-angle lens what do you do if you can’t find any foreground? Panic, obviously. When you’ve stopped panicking use your brain. You don’t actually need much to create what looks like an interesting foreground. Have a look at this next photo.
This shot taken in Scotland a few years ago relies on that big foreground to anchor the image, and the textural quality gives us something to look at as we wander up to the old building. It’s just a bit of dried grass – so even a melange of grass can do the job. Admittedly it wasn’t as effective in colour but with a small amount of processing a decent black & white image has resulted.
Aperture choice and depth-of-field
With wides in general, and especially with ultra-wides, you get lots of depth-of-field built in, thanks to the short focal length. That means you can get shots that appear sharp from front to back at larger apertures that wouldn’t be possible with longer focal lengths. While this may be great for those super-sharp landscapes that your viewer can seemingly ‘walk into’ (more on this later), it does present a challenge if you want to create pictures with a narrower zone of sharp focus and a diffused background, like this woodland image.
Although its more challenging, it’s not impossible, as the key to shallow-focus success lies in the focusing distance. If this is towards your lens’s minimum (which will be around 20-28cm on an ultra-wide zoom) then you can still throw your background out of focus, provided the thing you want to be sharp is just 20-28cm away. And remember that focusing distance is measured from the sensor plane – not the front of the lens, so you’ll be pretty close to your foreground subject. With the lens cranked back to its minimum focusing distance, you’ll easily get background blur, and you can accentuate it even more by opening up the aperture to f/4 or f/2.8.
But while limiting depth-of-field with a wide-angle makes a change and gives a decent creative option, the norm is to extend depth-of-field though the photo from the foreground to the distance. Ignoring processing tricks such as focus stacking, the best way to achieve maximum depth-of-field is to focus in the right place! We’ve covered Hyperfocal Distance before here, so read back if you want. Otherwise just stick with the simple rule of focusing one-third into the composition, just as we’ve marked on this image.
The one-third rule and f/16 have given us a pinsharp foreground and a pinsharp viaduct. It’s not rocket science, it’s just that the hyperfocal distance point which is roughly one third into the composition, is going to maximise sharpness both in front and behind it. You can work it out more precisely for your lens but frankly, life’s too short, right?