Intermediate Tutorial 7
Thinking of investing in additional lenses for your system camera? This second part of our examination of the different types looks at wide and super-wide-angle lenses, fish-eyes, pancakes and macros. Learn also what ‘fast’ and ‘bright’ mean, and how to compare a lens’ angle of view to our own.
Interchangeable Lenses Explained – Part Two
In the previous tutorial, we looked at the more common standard and telephoto lenses.
In this follow-up, we are moving on to the more specialised lens types.
Let’s recap some basics
We know that all lenses are referred to by their focal length and have a maximum angle of view (usually found in the specification), but how can you tell how much of the scene will be captured by the camera’s sensor when fitting different lenses?
This is a tricky question, because as we know, digital camera sensors vary in size and the sensor size in relation to the focal length, affects the end result.
Of course, there are complex equations for calculating angle of view for different focal lengths and sensor sizes, but for quick reference we need something simpler that all photographers are familiar with: the 35mm film frame and the angle of view it delivers and another thing we all know is how we view the world ourselves.
When looking straight ahead at a fixed object, a person’s clearest area of vision covers approx. 45-50 degrees, similar to the 47° angle achieved with a 50mm focal length lens. So, we can use this standard lens as our point of reference.
If a 50mm lens gives the same view we see, then a 25mm lens will see twice as wide – and a 100mm lens half. Remember: the longer the focal length, the narrower the angle of view.
To realise the angle you might get from your camera and lens, consider the ‘crop factor’ of the sensor and use it to convert the focal length of your lens to the 35mm film equivalent. So, a 25mm Micro Four Thirds lens and a 2x ‘crop factor’ achieve the same angle of view as a 50mm lens – roughly a human’s central visual field.
Technically, any lens with an angle of view wider than a human’s can be considered wide-angle, but we tend to so classify only those with 24-35mm focal length.
Wide-angle lenses are used when trying to shoot large groups of people – when you can’t get far enough back to fit them all in – or wide vista landscapes, of course. But these are by no means their only uses. Two other great features when shooting with wide-angle lenses are an exaggerated perspective effect and deep focus.
Due to the wide angle of view and the generally close focus distance of wide-angle lenses, it is possible to exaggerate the perspective of subjects, used to great effect in the example (right) that was shot by eddy from the LUMIX Experience community.
The ghostly shipwreck leaps out at you due to the striking perspective effect.
When shooting landscapes, wide-angle lenses offer a greater depth of field at any given aperture compared to telephoto lenses, so details in the foreground as well as way off into the distance can be captured in focus such as in the image on the right.
Ultra-wide and fisheye lenses
Lenses with focal lengths below 24mm are known as ultra- or super-wide. When the angle of view exceeds 100 degrees, it makes for some extremely interesting images due to greatly exaggerated distances between the nearest and farthest objects in shot. This can be used to good effect by getting very close to an object and using that as your focal point to dramatise space in your composition.
This image by Gordon Simm (above), was taken with a LUMIX Ultra-wide 14-28mm (equivalent) zoom lens and demonstrates a stretching effect on the lamppost and building, drawing your eye towards the flower basket.
Fisheye lenses add another creative dimension, deliberately adding distortion to the whole image. Due to the ‘curvilinear’ lens, barrel distortion occurs in the image and seems to emphasise the extreme 180° angle of view – pushing, even, the limits of human peripheral vision.
This effect can make even everyday objects and scenes leap out at the viewer, as in these great examples, from the LUMIX G gallery, below:
Their super-compact dimensions compared to regular lenses – usually under half the size with the same focal length – gives ‘pancakes’ their name. Ideal for travel, they can fit on an ultra-compact system camera that still fits in your coat pocket!
With a fixed focal length, these are ‘prime lenses’ with excellent optical quality and often, a wide aperture – shallow depth of field – ideal for portrait photography and low indoor lighting.
At just 20.5mm long, this Lumix F2.5 28mm (equivalent) pancake lens takes beautiful outdoor high-speed shots or indoor low light shots, like this image (right) supplied by Spongo53.
A true macro lens reproduces an object actual size, across the whole width of the camera’s sensor, when that subject is the minimum focal distance away. In other words, it has a 1:1 magnification ratio – compared to regular lenses’ 1:0.2 to 1:0.16, meaning objects are far smaller on the sensor than in real life. The advantage is that at 1:1, small objects can be photographed with incredible detail, very close up to the lens and appear large in the image.
Macro lenses also incorporate a ‘flat field’ focus system, so the focus plane is flat across the entire image. So, if you shoot a postage stamp, say, with your lens parallel, its entire flat surface is in focus with no softening at the edges.
Be warned, though, depth of field is miniscule – in macro shooting, picking your focus point is a fiddly business!
These shots demonstrate the extremely shallow depth of field, meaning a tripod is almost essential to ensure your focus area does not drift.
The term ‘fast’ refers to the shutter speeds that can be used when a lens offers a maximum aperture in excess of f stop 4. They are also called ‘bright’ because a wide aperture allows in a great deal of light. These lenses not only enable faster shutters, even in low light, but the wide aperture = offers a very shallow depth of field, too – making them preferred for portraiture and sports shooting alike.
Professional photographers appreciate the advantages of being able to shoot ‘fast’ wherever movement is involved, but the technology and craftsmanship required to produce these lenses comes at a price… so be prepared to start saving!
These two beautiful shots by ‘BigRed’ show the advantages of a fast lens to good effect. The first was shot hand-held at f1.8 and 1/1600th sec – ensuring sharp detail of the bee while at the same time defocusing its surroundings. The twig shot perfectly demonstrates the smooth ‘bokeh’, or aesthetic blurring, effect; it was shot with a Leica 25mm lens at f1.4.
The LUMIX Advantage
With the largest line-up of lenses designed for the Micro Four Thirds digital camera system, Panasonic and Leica offer a range of high-performance lenses that include super-zoom, super-telephoto, super-compact power zoom and pancake primes, super-fast, ultra-wide-angle and Fisheye.
No matter what style of photography you are into, there will be an amazing lens to satisfy your creative need:
In the next tutorial in this module, we’ll be moving on to using a flash and overcoming lighting issues.
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