Canon brings to the EOS 5D after much hesitation and a camera with 50-megapixel full-frame chip on the market. One wonders as highly ambitious photographer inevitably: Is such a purchase makes sense? And maybe they even replaced the much higher investment into the digital medium format?
Let's not talk long about the bush: The problem is not the many pixels on the sensor, but the question of whether they are in this abundance can detect with the available lenses at all. An industry representative put it recently to the point: "Ten percent more pixels can be pretty easy to pack on a chip - but just try to increase by ten percent the resolution of a good lens. That's almost as elaborate as the reinvention of the lens. "The new Canon we now have to deal with over 100% more pixels.
One can try to be this rather diffuse contexts in numbers: The best of the current high-end lenses range just made to resolve an image in a subtlety that (a sensor with pixels of an edge length of six microns 10-6m) owns. In other words around: Are the pixels on the image sensor less than six microns - as with most cameras - need the small pixel higher resolution lenses to fully demonstrate their resolution benefits. The problem already have the Nikon D800 / 810 and the Sony A7R with its 4.8-micron pixels: There is no lens - not even the legendary, high-resolution Zeiss Otus 55 millimeters - that the 36 megapixel resolution of the cameras "on the road brings ". How should it then be only at 50 megapixels with 4.14 microns?
Megapixel without end?
According to measurements of DXOmark.com, The central authority for such matters, is reaching the end of the road even at 29 megapixels for example in the Nikon D800. The implication is simple - and perhaps also explains the reluctance of manufacturers: A full-size camera should have no more than 24 megapixel resolution, A APS-C camera theoretically only nine and a sensor in the 4/3-format can modestly with five megapixels, That was the way the resolution, which described Olympus in his first 4/3 system as "well as for professional purposes perfectly adequate". Which although more of pixels on the chip to increase the resolution entails, but as "oversampling" effect. The optical signals of the lens to be processed with a higher sampling rate than is needed to represent the signal bandwidth. This leads practically impossible to higher-resolution images, but by far to the extent as the higher megapixel numbers want to make us believe. And they are due to increased oversampling resolution also not necessarily "better".
Ein Ausweg aus dem Dilemma sind bei gleicher Objektivkomplexität größere Sensoren mit mindestens sechs Mikrometer großen Pixeln. Bisher scheitert dieser Weg der Qualitätsoptimierung an mindestens zwei Hindernissen:Große Sensoren sind teurer als kleine. Außerdem erfordern sie größere Bildkreise und damit größere Kamera-/Objektivkonstruktionen. In den vergangenen Monaten gab es viele Gerüchte, dass Canon, Nikon, Sony und Fuji den digitalen Mittelformat-Markt in den Blick nehmen. Diese wurden besonders durch den Sony-CMOS-Mittelformat-Sensor befeuert, der sich sowohl in den aktuellen Hasselblad- und PhaseOne-Rückteilen als auch in den Bodies der aktuellen Pentax-645-Generation befindet. Doch das Mittelformat unterliegt ebenfalls den physikalischen Gesetzen der „Sechs-Mikrometer-Regel“. Für die „großen“ Mittelformat-Chips mit circa 4 × 5,4 Zentimeter Kantenlänge liegt die Maximalauflösung bei rund 60 Megapixel. Wohlgemerkt: Auch die können nur die besten Mittelformat-Objektive auflösen. Bei dem oben erwähnten Sony-Chip mit rund 51 Megapixeln auf 44 × 33 Millimeter Fläche liegt die Pixelgröße jedoch nur bei 5,3 Mikrometer. Die Idealauflösung für diese Sensorfläche wären etwa 37 Megapixel. Zufällig der Wert, den Leica bei ihrem S-System bietet, das einen ähnlich großen Sensor verwendet.
In short: It is unlikely that one makes much better pictures with a 50-megapixel full-frame than with 24-megapixel resolution. Secured, only that the amount of data is twice as large. Therefore, one can imagine the missing pixel interpolation should in principle also in Photoshop when you because even need a house wall-sized print.
The benefits of the expensive medium-format systems are not necessarily in the higher amount of data. Although details are recorded a touch differentiated, does not make the difference between a good picture and a bad one. The system differences are more complex: First, the medium format will force a systemic by its inertia or awkwardness another style of work than we know it from the small picture. Secondly, the result looks sometimes a bit more interesting because you get with longer focal lengths at the same distance a minimally different, often somewhat pleasing perspective. Then there are the moments when you look at a photo and know that it was made with a larger format, without being able to say exactly what it shows. Who is it, who can not avoid the issue of currently around 30,000 Euros for as a 60-megapixel back. The right camera and lens are usually included in the price. stay awake!
update: Have just seen in the Nikon D800E DxOMark well and the D810 with the Zeiss Otus 55 have now been tested: The result: 33 megapixel resolution at 36 megapixel chip. The Otus 85 removes even 35P-Mpix on to the D810. Let's see how the 5Dsr strikes itself in the measurements ...