Pixels vs Sensor Size
The luxury about buying Refurbished Olympus Cameras is that the vendor goes to a great amount of trouble to highlight the Pixels size and Sensor size of the camera in his advertisements.
It Pays to Think Big With Digital Camera Sensors
Jack Schofield: A camera’s mega pixel rating can be misleading because it stops people thinking about sensor size I’ve just bought a new digital SLR camera, my old one having failed, and been reminded just how fast these things change.
I went for a Nikon D40 for 250 (after cash back), which is less than half what I paid for my first digital camera, an Olympus Camedia compact. One thing hasn’t changed: buyers still have to negotiate the pixel inflation problem. In my case, this meant choosing a D40 that records six mega pixels (6MP) rather than the newer D40x, which offers 10MP. Both have the same size light-capturing sensor, much the same body and the same lenses, so the D40x is unlikely to produce noticeably better pictures, despite having 66% more pixels. You should see a difference if you print pictures bigger than 11 x 8 inches, but you won’t see it on screen or in the Technology section. Maybe you would see it if you crop images, but I grew up with the Henri Cartier-Bresson Adoration Society, and always use the whole frame. Anyway, it felt like a bargain to get what was a 450 camera for 250. It’s amusing, in hindsight, that the camera review site DP Review welcomed the D40 by saying: "The biggest news however is probably [the] fact that Nikon resisted the temptation to keep chasing mega pixels (hooray for that) and instead appear to have concentrated on what makes a good camera." (tinyurl.com/yhte7g). Nikon’s resistance was so strong that the D40x was launched only four months later … Pixels are, of course, important. As someone with three Canon 35mm SLRs and more lenses than would be polite to mention, I certainly wasn’t willing to pay any price for early models that captured 640 x 480 pixels or 0.3MP: the same resolution as a VGA screen. Any pixels you don’t capture at the scene are lost forever. For comparison, my 1.3MP Olympus compact offered the resolution of an SXGA (Super Extended Graphics Array) screen, which is 1,280 pixels across by 1,024 pixels down. This is enough for snapshots, websites and most newspaper uses. A 6MP camera gets you up to about 3,000 by 2,000 pixels, enough for a 15 x 10 inch print, if the image is printed at 200ppi (pixels per inch). Beyond 6MP, it’s the law of diminishing returns: you get more pixels, but if the pixels are smaller, you also get more noise (tinyurl.com/k2ma4). This can make the image worse rather than better. To benefit, you need a camera body/lens that delivers more resolution (to exploit the smaller pixels) or does a better job of noise reduction – preferably both. This should not be a surprise. Nobody expected a Box Brownie to produce the same image quality as a Hasselblad simply because they used the same film. In fact, a camera’s mega pixel rating can be misleading because it stops people from thinking about sensor size. In the days of film cameras, many or most people knew that a bigger negative generally produced a better quality image. The sensor in a digital camera is the equivalent of the film, and having a bigger sensor also makes a difference. Nikon’s "prosumer" models such as the D40/50/60 have sensors that are roughly half the size of a 35mm negative, whereas the 12MP professional D3 has a full-frame (36mm x 24mm) sensor, albeit for 3,300. If you want more, you can get a 39MP Hasselblad H3D-II with a sensor twice the size (48mm x 36mm), for something over 20,000, and that’s without the lens. Buy a compact camera, however, and the sensor could be anything from 2/3 (8.8mm x 6.6mm) to 1/2.5 (5.8mm x 4.3mm). I’m sure somebody can get 6MP out of a 25 sq mm sensor, but can it match 6MP from a Nikon D40’s 370 sq mm sensor? No way.
| © Guardian News & Media 2008 Published: 3/5/2008 |
Most of the digital cameras have auto-focusing which enables even a kid to take decent photography. The LCD viewer helps in getting the right composition of the image. The preview of the images clicked allows keeping the best one from the lot and deleting the rest thus saving on space for more clicks.
