berikut ini, katanya, artikel di BJoP (British Journal of Photography)... mungkin yg langganan bisa konfirmasi.

'There are no plans for a full frame camera,' says Jeremy Gilbert, imaging division group marketing manager with Nikon UK. 'We'd never say never to the idea, but it's not in the plans. We believe the DX format offers the best combination of value and performance.'

article on the different sized sensors and the system implications

good for you nikonian... 8-}

wah, maap, broken link... berikut text-nya

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The first digital camera I ever used was a Kodak DCS200. The first self -contained digital SLR, it hit the market in February 1994. Boasting 1.5 million pixels, it stood more than twice the height of the Nikon F801 on which it was based, thanks to a built-in 80MB hard disc and a battery that, with good luck, would last for 100 images. That, of course, was without using the monitor, for there was no monitor. Retailing at £8000, Kodak was not rushed by an Ikea-like stampede of buyers.

We can laugh now, but this was truly the pioneering era of digital photography. The DCS200 was little more than a prototype that Kodak was willing to sell to the unreasonably well-heeled and curious. And one thing in particular marked it out as straight from the laboratory test bench, something that became evident the moment you put the camera to your eye and saw the world reduced to a tiny, distant square in the centre of the viewfinder. The sensor chip was so small that it cropped the viewfinder image by 2.5 times, so that the 28mm wide-angle fitted to the demonstration camera gave the coverage of a 70mm lens. Its applications were limited, to say the least.

We have moved on since then, but the field of view cropping factor is still with us and is still causing angst to some photographers. Only two manufacturers - Canon and Kodak - are currently producing cameras with full-frame sensors, and there was much speculation as to whether the Nikon D2X would be fitted with a full-frame sensor. It wasn't - Nikon stayed with its 23.7x15.7mm DX sensor dimensions, which imposes a 1.5x crop.

Some potential buyers were disappointed and questioned Nikon's commitment to professional standards. Various Nikon user websites have been alight with posts asking if they are ever likely to get a full-frame camera to match Canon's finest.

Clearly, many photographers believe that full-frame should be the ultimate goal of any manufacturer in the professional market. But maybe it's time to step back a pace and reassess the situation. Full-frame sensors do have their advantages, but small sensors also open up some interesting possibilities. Nikon's strategy may ultimately prove to be the more forward-thinking long-term option.

Who uses what?

Before pursuing this line of argument, it's worth recapping the various sensor sizes currently used in 35mm-derived cameras.

Full-frame (24x36mm) is used by Kodak in its Pro SLR/n and /c models, and by Canon in the EOS 1Ds Mk II. Next down the scale is the 19.1x28.7mm sensor fitted to the Canon EOS 1D Mk II - the so-called APS-H sensor, although it equates only roughly to this film format. This chip imposes a crop factor of 1.3x.

Then there's a raft of sensors of around 15x23mm, collectively known as APS-C sensors, though again the link to the film format is tenuous. The exact size used in all Nikon models is 15.7x23.7mm, which the company calls the DX format. Pentax and Konica Minolta use the same format and sensors close to this size are used by Fujifilm in the S3 Pro and by Canon in the EOS 20D and 350D. These impose a crop factor of around 1.5x. Sigma is out on its own, with its SD10 using a Foveon chip measuring 13.8x20.7mm, equating to a 1.7x.crop, but all these sensors adhere to the traditional 35mm aspect ratio of 2:3.

In addition to these is the Four Thirds format, currently only used by Olympus in its E-System cameras. These cameras use a chip measuring 13.5x18mm, with a diagonal of 22.5mm, which is almost exactly half of the 35mm diagonal. Being a system designed around this chip size, it doesn't impose a crop factor, but focal lengths are halved, compared to 35mm, for any particular angle of coverage.

Canon and Nikon make the most DSLR models and they are clearly intent on taking very different approaches. Canon has four models using three chip sizes, while Nikon has four models, all using the DX format. Nikon has no intention of building a full-frame camera in the foreseeable future.

'There are no plans for a full frame camera,' says Jeremy Gilbert, imaging division group marketing manager with Nikon UK. 'We'd never say never to the idea, but it's not in the plans. We believe the DX format offers the best combination of value and performance.'

Why full-frame?

In their transition to digital capture, manufacturers understandably wanted to retain existing lens systems, and this dictated that DSLRs were derived from established 35mm systems. Olympus was the one exception, having been out of the professional market for so long that it had virtually no user base to worry about. All other manufacturers had to make the economic impact of switching to digital capture as financially painless as possible.

The logical extension of this was to make the lenses work exactly as they did with film, with no cropping factor. Full-frame seemed the ideal, eliminating the problem of restricted wide-angle coverage. Anything less than full-frame was generally seen as a compromise between cost and usability.

But while this used to be a valid argument when wide-angle coverage was seriously curtailed by the lack of adequately wide lenses, it now rings rather hollow. The problem went away when manufacturers started making ultra-wide lenses specifically designed for the DX format. Both Nikon and Sigma now make 12-24mm zooms, while Nikon makes a 10.5mm prime lens that gives coverage equal to a 16mm lens on 35mm. At the time of writing Sigma had just announced a 10 -20mm zoom. So there are plenty of options for those who need to compensate for lost wide-angle coverage.

Of course, these lenses cost money, and users might reasonably resent having to buy another lens when they already own a set that would meet their needs with a full-frame camera. But in reality a DX camera costs a lot less than a similarly specified full-frame camera - and in fact you could have a DX camera and lens for less than the cost of a full-frame camera body.

And the image cropping factor has a flip side when working with telephoto lenses. Rather than being a disadvantage, it works in the photographer's favour by allowing them to use smaller, lighter, faster lenses for equivalent tasks. Take the example of two photographers working side by side, one using a full -frame camera with a 600mm lens, the other using a DX-format camera with a 400mm. The 400mm on the DX camera gives the same pulling power, but from a lighter and more compact lens. Furthermore, the 400mm is available with a maximum aperture of f/2.8, while 600mm lenses top out at f/4. Which would you rather be using?

Circle of coverage

Full-frame lenses need a circle of coverage 43.3mm in diameter, DX lenses need cover only 28.5mm, while Four Thirds lenses cover 22.5mm. As the circle of coverage increases, the technical constraints faced by lens designers multiply. Maximum apertures are reduced to keep optical aberrations within acceptable limits; lenses become heavier as more glass is needed to create the larger image, and costs rise proportionally as manufactur ing becomes more complex. That's why medium format lenses are slower, larger and more costly than 35mm. Conversely, lenses with a smaller circle of coverage can be faster, lighter and cheaper than 35mm optics.

It's the combination of reduced circle of coverage and the need for shorter focal lengths that makes small sensors such an attractive option - a fact becoming particularly evident with the Four Thirds System. The Olympus range includes a 150mm f/2 lens that is equivalent to a 300mm on 35mm, such an aperture is unheard of in a 300mm lens. New in the range is a 90-250mm f/2.8 zoom, equivalent to a 180-500mm lens. Again this is an aperture not available in the 35mm equivalent.

Lens resolution

But while small sensors have some clear benefits, they do introduce their own set of technical hurdles.

One of these is lens performance. As chip dimensions decrease, lenses need to focus the same amount of detail onto a smaller area, so resolution has to increase. It surprises many people to learn that some high quality digital compacts, in which the sensors are far smaller than anything found in any SLR, often have lenses with far greater resolving power than high grade 35mm optics. Even the Four Thirds system requires lenses with twice the resolving power. Olympus made a point of this when the system was launched, claiming that its lenses meet this demanding parameter.

Lenses for any film format have generally been designed with sufficient resolution for the intended format, and little more. High-grade 35mm lenses are no exception, despite the fact that many photographers regard them as the last word in sharpness.

This brings us to an interesting point. If lenses designed for the 35mm format are used with a DX sensor, they are unlikely to have sufficient resolving power to produce optimum quality. Nikon's new DX lenses are actually built to a higher standard to compensate for the reduced image size.

As sensor resolutions grow and more photo diodes are crammed in, the limitations of 35mm lens resolution are becoming increasingly evident. With some high resolution digital cameras, it is now possible to detect differences between lenses that remained undetectable on film - and that means lenses are already starting to become the quality bottleneck.

Lens design

Resolving power is not the only limitation of conventional 35mm lenses. One of the most obvious faults in many digital images is the presence of colour fringing along high contrast edges away from the centre of the frame. This occurs even with high-grade lenses that produce perfectly good images on film. It arises from the fact that digital sensors are very unforgiving when the light strikes them at a glancing angle. The problem is most evident with wide-angle lenses, from which the light rays emerge at a steep angle. The extent of the fringing can be quite severe and visually intrusive at moderate enlargements.

Image fade-off or vignetting is also more pronounced in digital images than with film. To understand why this is so, think of a grain of film as a ball and a photodiode as a flat plate. The grain of film presents the same profile regardless of what angle the light is coming from, while the photodiode presents an ever-diminishing profile as the angle of view steepens. A photodiode near the edge of the frame catches very little light from the steeply angled rays of a wide-angle lens.

There is a single solution to both of these problems, but it requires lenses built to a different optical design. The telecentric design, as it is called, shapes the emerging light into a wide column in which the rays remain close to the lens axis. The result is that light hits the sensor close to the perpendicular, regardless of focal length.

But this poses a problem for manufacturers using full-frame sensors. To accommodate this lens design, the camera's lens mount opening has to be approximately twice the diagonal of the sensor - and there is no 35mm camera mount on the market that even approaches this requirement for a full-frame sensor. The Nikon lens flange opening, at 45mm, is barely more than the 43.3mm frame diagonal. Canon's mount, at 48mm, is just marginally wider but still a long way from being able to accommodate telecentric lenses. For full-frame cameras to meet this requirement they would need a flange opening of 87mm - wider than the opening of a 6x7cm camera.

Even with a DX sensor, all existing 35mm mounts fall well short of the ideal, although Nikon does apply the general principles of telecentric design in its DX lenses to beneficial effect.

The Four Thirds system was designed with this requirement in mind and, at 46mm, the flange opening is a little more than twice the sensor diagonal. It is because of its large lens flange opening that the Olympus E-1 is not a great deal smaller than a 35mm SLR.

Telecentric lenses are not technically possible with full-frame cameras using existing mounts, so these optical problems can't be eliminated.

The only option is to minimise their effect during image processing.

Sensor sensitivity

A small sensor tends to generate more image noise than a larger one of equal resolution. This is because the photo diodes have to be smaller to squeeze into the smaller area, which means they catch less light and are less sensitive. To counter this, the signal has to be amplified more and this degrades the signal to noise ratio.

While the above principle is true, it over-simplifies the issue and doesn't always reflect what happens in practice. One of the least noisy sensors currently available is the APS-C chip used in the Fujifilm S3 Pro, one of the noisiest is Kodak's full-frame sensor. There are too many other variables and different technologies for such a generalisation to hold true.

Some chip designs minimise the area taken up by the wiring that carries the signals away from the photo diodes, making more efficient use of the available space. Some chips use microlenses to focus light from non-sensitive areas onto the photo diodes, and some don't. These and other design differences often outweigh the effect of sensor size.

Depth of field

One of the effects of using a small sensor is that it increases the depth of field, but whether this a good or bad depends on the type of work being undertaken. Fashion and portrait photographers might well prefer the isolating effects of a shallow depth of field, while many others will welcome the extra depth.

The difference arises because smaller sensors require a shorter focal length for a given composition.

This is offset to some extent by the fact that they must be assigned a smaller circle of confusion value to account for the larger degree of enlargement required. Without going into the calculations here, the effect is that, at a given aperture, a Four Thirds camera will produce twice the DoF of a full-frame camera. To achieve the same DoF with a full-frame camera, it would be necessary to stop down the lens by two stops.

A DX sensor will increase DoF by about 1.5 times at a given aperture, and a full-frame camera would have to be stopped down by one stop to produce approximately the same effect.

The image-degrading effects of diffraction also need to be considered when using a camera with a small sensor, as the effect sets in at a wider f-stop. With a full-frame camera, diffraction effects only become significant at f/16 or smaller, but with a Four Thirds camera it becomes noticeable from below f/11. For optimum lens performance the aperture setting should be kept above this setting.

Where to now?

Clearly there are more important considerations to consider than the crop factor imposed by small sensors. What we should be seeking now is the format that offers the best possible platform for exploiting the potential of digital capture. It would be a truly remarkable coincidence if this just happened to be the 35mm format adopted, largely by accident, 80 years ago, for a totally different capture medium. This format has served photography well, but it simply doesn't square with the optical and physical considerations of the digital medium. It's time to move on and start thinking small.

FLEXIBLE FORMATS

MULTIPLE ASPECT RATIOS

A camera fitted with a chip that covered the whole image circle could be used to switch between multiple aspect ratios. With a Four Thirds camera this could be achieved with a chip measuring 22.5x22.5mm.

All the 35mm derived cameras use the traditional 2:3 aspect ratio, which is not always the most appropriate for the task. There really is no reason why digital cameras need stick to this format, as the companies behind the Four Thirds standard realised. Contrary to popular belief, manufacturers who build cameras to this standard do not have to adhere to the 3:4 aspect ratio used by Olympus. Providing that the diagonal of the image is 22.5mm they are free to use any shape they like, from square to panoramic.

Technically, it would not be difficult to build a camera with variable aspect ratios. Provided the chip filled the entire circle of coverage, it would be possible to create any aspect ratio. The technology to achieve this involves being able to switch out certain sections of the sensor, and is already being used by Nikon in the D2X, which switches to a cropped down section of the chip in its high-speed mode.

A format that might appeal to editorial photographers is 1:1.41, which is the aspect ratio of the A-series paper sizes. This shape would make more sense when shooting a magazine cover or double-page spread. Social photographers might prefer 1:1.25, which enlarges to exactly to 4x5, 8x10 and 16x20 inch ratios. Landscape photographers would be able to choose a shape to suit the situation.

Mechanically, this would not be difficult with Four Thirds cameras as they are being built from the ground up. Cameras derived from 35mm models would be much more problematic as the existing shutter gate height would prevent filling the entire image circle with sensor. The effect could still be achieved, but only by cropping into the captured rectangular area. Digital APS, if you like.

How the professional market benefits from digital compact design

Professional digital cameras are enjoying the trickle-down of technology developed for the consumer market, particularly in sensor technology.

Competition in this sector is fierce and driving development at a rate that could never be sustained by the professional market alone.

Much of this development goes into improving the performance of small-scale sensors. For instance, Panasonic, now a partner with Olympus in developing Four Thirds cameras, recently announced a sensor with two micron elements. The previous record was 3.1 microns. In developing this new chip, Panasonic reduced the conductor path wiring from 2.5 to 1.5 microns, providing an extra 40% of the chip space for light-gathering. Despite doubling the number of photo diodes in a given area, noise should not increase. This sensor, if scaled up to Four Thirds size, would have around 36 million pixels.

good reading. Makasih infonya.

Pake d70 ajah udah cukup kak Radix ...

kak Wiwin,
cukup sekali kak! nanti kalo 10 tahun lagi D70 tsb mati, tinggal beli body D99 seharga 2 juta, dan lensanya masih bisa dipake. Kalo beli Rebel XT, nanti 10 tahun lagi waktu 1Ds Mk13 keluar dan harganya cuma 3 juta, lensa EF-S nya ga bisa dipake deh... ;))

Psssstttt...Nikon D50 udah diregistered loh jeng.....;;)

Terjemahin lah Pak Cik. Awak nih org melayu. Mana pula bisa cakap org bule.

IMO, nggak full frame nggak masalah ...
Kalau kurang wide, beli lensa DX. Apalagi beli lensa lete, pasti dapat keuntungan focal length bertambah panjang karena dikalikan 1.5x. Buat yang punya uang lho ...

Full frame atau bukan full frame, yang penting motret harus jalan terus :D

Mau full frame terserah, mau kagak juga gak 'patheken' :D

Kalau kayak saya sih belum merasa perlu pakai full frame digital, toh kalau mau full frame bisa pakai kamera film. Kalau professional kan memang maunya lain, musti perfect gitu kali yak?

Barang-barang termasuk kamera dibuat untuk dijual dan kemudian dipakai. Kalau nggak ada yang mau pakai, nggak ada yang mau beli, ngapain susah-susah dibikin :p

ahhhhhhh, saya lupa, kalo ada ujar-ujar "pembuat kamera hadir di muka bumi tidak untuk menyelamatkan dunia, tapi untuk menjual produknya"...

mumpung lagi di topik ini, berikut link yg udah pernah di posting tapi mungkin berguna juga ditaruh sekali lagi disini. Diskusi mengenai Full Frame antara Mike Johnston dan Michael Reichman di Luminous Landscape:
Thoughts About "Full Frame"

oh ya, satu lagi yg mungkin menarik juga diskusinya: Nikon the conservative dan Canon the agressor ... plus lain lainnya .... sebuah pemikiran di product strategy

:-? bukannya udah lama tuh berita kaya gini? gua kayanya udah taunya dari taon kemaren ye ;))

tapi dengan 1.5 crop at least nikon persistent . kalo kaya gua canonian ada 3 type , full frame, 1.3 and 1.6, kalo mao beli lensa mesti mikir dulu apakah ini bisa masuk ke tiga tiganya. salah satu factor gua rada males beli 10-22 soalnya nga bisa masuk ke 1.3 and full

Emang udah lama kok ing... dulu banyak orang sempat skeptis kalau Canon akan mengeluarkan pengganti EOS 1Ds. Ternyata keluar juga 1Ds Mark II. Ngapain dibikin kalau nggak ada yang mau beli? Ongkos R&D nya aja muahal banget tuh pasti :-?