Beginner's Guide 6 ? Lenses And Focal Lengths

Article by Mike Browne - www.photographycourses.biz

Hello and welcome to my first beginners guide of 2012. I hope you all had a Cool Yule involving loads of new cameras and lenses and a happy New Year.

If you did get a new lens for Christmas or just want to get to grips with the ones you have already then you’re in the right place – as you've probably worked out for yourself because of the title.

There are basically two types of lens. Consumer lenses and professional lenses – sometimes called 'fast' lenses because they have a wider maximum aperture which allows you to set faster shutter speeds. A professional lens generally costs about £1000 more than its consumer equivalent so I guess the first question is "Can I still take great images without spending a fortune on a professional lens?"

And the answer is: "Yes, absolutely you can!"

Those of you who have joined our photography videos area on our website will have seen me using quite an old consumer lens most of the time because I want everyone to understand great photography isn’t about expensive kit – it’s about learning how to use what you've got.

There are benefits to using fast ‘Pro’ lenses such as wider apertures which let in more light, and allow you to make beautiful blurred backgrounds because of their inherent shallow depth of field. Optical quality is better too but you usually have to look very hard to tell the difference. If you’re interested to find out more take a look at our Pro vs Consumer Lens Test video.

There are three main lenses I recommend you have so you’re covered for all occasions.

Wide Lens

This is a lens with a short focal length which could be anywhere from 8mm to about 30mm. The lower the number the wider the angle of view of the lens. In the case of a wide angle zoom lens it might be something like 10-20mm.

A wide lens gets more into the picture and is great for big scenes in landscape photography and interiors when showing an entire room. To fill the frame with a subject such as a person or a house you need to be very close to it or they’ll appear very small in the image. Wide lenses are also known as ‘short’ lenses because of their low focal length.

Medium or Standard Lens 

Lenses of around 50mm up to 100mm are known as standard, mid range or medium lenses because their focal length is neither wide or long. A medium range zoom lens would typically have a focal length ranging between about 18mm and 70mm. When using a mid range lens at about 50mm you’re seeing the world in roughly the same way we see it with our eyes.

Long Lens

A lens with a focal length capability of more than 100mm is generally termed as being a long lens. Probably the most common long zoom lens would have a range from 70mm up to 200mm. Long lenses magnify more powerfully so they’re great for bringing far off things in closer, but they’re brilliant for isolating things like flowers or someone’s face in a portrait because they’re the opposite of wide lenses in that they have a narrow field of view - a bit like looking down a cardboard tube.

But what about 'Focal Length'?

If you’re just starting out it can be a bit confusing and I know focal length can often be confused with f stops – another way of saying apertures.

Focal length is a measure of how 'zoomed in' you are with your lens and it’s expressed in mms. There's no 'correct' focal length, you just set it according to how much 'zoom' you need to make the picture look how you want it to.

Yes you read that right – I said: "set it according to how much 'zoom' you need to make the picture look how you want it to".

Zoom lenses aren’t just for making far off things come closer – they affect how the image looks too.

Here are three images from our photography training DVD, Digital Photography Exposed – the movie. In each one Tasha my model is occupying the same space in the frame but look at the difference between them.


This shot was taken with a wide lens using a focal length of 18mm.


Same shot with a medium lens using a focal length of 70mm.


And again using a long lens and focal length of 210mm.

Big difference! Once you understand how your focal length affects the way your images look it opens up a whole new world of creative possibility. To do this you obviously have to move yourself according to the focal length you choose, rather than zoom in and out hoping it’ll come good at some point. I’m not sure who it was that said the wise words "The best zoom lens is your feet." But I completely agree with them.

Let me show you how it works with this clip from Digital Photography Exposed – the movie.



To practice this technique start by checking what focal length you’re using each time you take a picture. To find out what focal length you’re using first compose the shot and zoom to where you need to. Then look at the barrel of your lens to see which of the numbers written on the zoom ring lines up with the white dot on the barrel of the lens.

After you’ve taken a shot try a different focal length, move yourself about to get the composition back as it was and compare the two images. As you practice you’ll become familiar with the appearance of short, medium and long lens images – and as you gain experience you’ll instinctively know which focal length you need to make an image look the way you want it to.

Next time let’s put all this together and make the image I showed you in beginners guide 1 of a car speeding down a country lane.

Until then get yourself out and about and have a play with those focal lengths – I promise you’re going to love them.

See you all in a couple of weeks.

Mike Browne - www.photographycourses.biz

You can read the previous tutorial in this series by Mike Browne here: How To Use ISO