Outdoor Photography. Chiz Dakin
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Название: Outdoor Photography
Автор: Chiz Dakin
Издательство: Ingram
Жанр: Спорт, фитнес
isbn: 9781849658690
isbn:
Kayaker on Ullswater, Lake District (Jon) Although a lucky shot in the sense that the kayaker just happened to pass by, it did help that I was already shooting the landscape and had the exposure settings already dialled
2 HARDWARE FOR THE OUTDOOR PHOTOGRAPHER
Mohammed Hammad, Jebel Khazali, Wadi Rum, Jordan (Jon) A wide-angle lens (27mm equivalent) makes the most of light and texture in the foreground
First Thoughts
There is no such thing as the perfect camera. There may not even be such a thing as the perfect camera for any one individual. What seems ideal when you’re shooting exquisite landscapes during a leisurely walk may be far less so on a spindrift-haunted winter climb or a wild mountain bike ride. Only if you specialise exclusively in one type of photography are you likely to get close to finding one camera that suits you perfectly all the time.
If you had limitless money you might think that owning lots of different cameras would be the answer, but actually it probably isn’t (we can’t say for sure as neither of us are in that position!). The more cameras you have, the more you might struggle to choose the right one for any given outing – the more, too, you might be tempted to take two or three to cover every eventuality and end up hating it because you’re so overloaded. And the harder it would be to feel really familiar and at ease with every camera.
Hang on, what about film? If you’re still using film and you’re happy with the results, stick with it. And if you really want to master photography in all its aspects, there’s definitely a place in the learning process for shooting, developing and printing your own black and white pictures. But apart from that, you’d need a very good reason to buy a new film camera today, and if you’re in that situation you probably know it already.
Emperor penguins, Antarctica (Chiz) The heart-shaped moulting pattern on this penguin chick is entirely normal, if unexpected
For most of us it’s a moot point anyway. Money isn’t limitless and we don’t have time to master lots of different cameras. In the real world, camera choice is always going to be a compromise. There’s no perfect camera but there are lots of good ones. It shouldn’t be that hard either to find the best camera for your needs or to get the best out of the camera you do have. But one thing is key, and that’s being as clear as possible about what you want. What sort of situations do you want to shoot in, and what sort of results do you want to achieve? Maybe these are questions you can’t answer fully until you’ve read the rest of this book. That’s OK. We had to put this chapter somewhere!
There’s one thing we can be pretty clear about. In the first edition of this title Jon was fairly sceptical about digital cameras – and with good reason at the time. But things changed pretty rapidly within the next few years. Quality went up, prices came down, and digital rapidly became mainstream. Today we feel fully justified in assuming that the vast majority of our readers use digital cameras.
Cameras
The sensor
The heart of every digital camera is the sensor, the image-forming chip which has taken the place of film. If you believe the hype, all that really matters about a sensor is how many megapixels it has. This is rubbish. Most digital cameras today have more pixels than you need, and there’s a strong argument that some have too many.
But first, what is a pixel anyway? The word is short (sort of) for ‘picture element’. In essence it’s a coloured dot. Blow up any digital photo big enough on your computer screen and you can see the individual dots of which it’s made. In a 6-megapixel camera, for example, there are (approximately) six million of these individual dots, in an (approximately) 3000 × 2000 pixel array.
Sunset over hills behind Garden Cove, Campbell Island, Sub-Antarctic New Zealand (Chiz) Bigger pixels are better at holding detail from deep shadows and bright highlights
Lyth Valley, Cumbria (Jon) It’s much easier to build wide-angle lenses for larger sensors – and without a wide-angle lens (24mm) this dramatic sky would have been lost
The camera’s processor has to read, record, and subsequently reassemble data from each and every one of these pixel-sites. Actually it has to do even more than that. The individual pixels in almost all cameras only record data of one colour. If you could enlarge an image straight from the sensor, you would see it’s made up of red, green and blue dots of varying brightness. Recompiling these into a genuine full-colour image is a complex process called demosaicing.
For each shot the camera has a lot of number-crunching to do before it can save a JPEG image file to the memory card. If that number-crunching power doesn’t keep pace, then adding more pixels will make a camera slower.
There’s another, even more basic, reason why the mere number of pixels is not the only issue. If you have two sensors of the same physical size, one with six megapixels and one with 12, it’s obvious that the individual pixel-sites on the 12mp sensor are going to be smaller; each will only have half the area, which means it can only collect half as much light. This may not matter too much when there’s loads of light around, but that’s not always certain in the great outdoors.
This indicates that we should be less obsessed with pixel numbers and more concerned with pixel size. Pixel size is determined by the number of pixels and the size of the sensor. However, while the pixel number is plastered all over advertising and packaging, you’ll usually have to dig deeper for any information on sensor size.
So here it is in a nutshell:
SLR-type camera: big sensor
Compact camera: small sensor
Mobile phone camera: teeny tiny sensor.
There are variations within each category – for more information, see under ‘camera types’, below – but very crudely, SLR sensors are somewhere in the postage-stamp size bracket. Compact camera sensors are smaller than your smallest fingernail. And cameraphone sensors are so small you can barely see them.
Even an HD TV screen is only equivalent to about a two (yes, two) megapixel image. So exactly who needs 14 or 16 megapixels?
To coin a phrase, you can’t change the laws of physics. There are physical limits, set by the wavelength of light among other factors, which mean pixels can’t go on indefinitely getting smaller and smaller. Cameraphones are close to the limit already. Ultimately, the only way to add more pixels will be to use a bigger sensor.
Alternatively, a bigger sensor allows the use of bigger pixels. Because bigger pixels grab more light they perform much better in lower light levels. This means less need to use flash, which is usually a good thing. But bigger pixels also produce cleaner, less noisy, images at all light levels. They’re also better at holding detail from deep shadows and bright highlights – something else which is often an issue in outdoor photography.
Of course bigger pixels require bigger sensors, which in turn means СКАЧАТЬ