Canon 1ds mkIII goes MF

As Focus in England and PMA in the states draw nearer, the Canon 2007 DSLR rumor mill comes alive again. This time, the flagship Canon 1DS MKIII gets a share of attention as images of site designs start to leak.



For a long time now, it has been asumed that Canon is working on a behemoth for the mid-format range.

What is mid-format? Well, any format bewteen normal film size "fullframe" (which is a film or sensor area of 36 x 24 mm with a 3:2 area relationship) and "big format" which is basically plate size photography measured in centimeters and not millimeters.. The Canon EOS 5D 12.8 MP Digital SLR Camera (Body Only) is an example of a digital fullframe 35 mm camera.

However, "fullframe" simply means using the full sensor area - "fullframe" is actually a term born within the midformat class, since changing backs on these cameras allows you to alter the amount of frame, or film illuminated. Enough.

The Canon 1Ds MKIII suposedly uses a larger than 36 x 24 mm sensor. The indication of a 4:3 area (in comparison to the 36 x 24 mm 3:2) assumes a 48 x 36 area, or double the area, and presumably pixels, of today. Based on the present Canon 1Ds MKII this would give 32 megapixels. It all depends upon pixel density of course.

A couple of points come to mind.. 1) who needs 32 megapixels? 2) How do you managed storage of these giant files? 3) What about noise and sensitivities?

ALl you have to do for answers is to look at the medium format community that today use Mamiya, Hasselblads and exchangable digital backs. All of these operate at these high megapixel levels. Here you also have the community that doubtless will want to put their hands on a weather sealed, ergonomic body of high megapixels.

The Problem solution
What is the biggerst issue that Canon and all dslr users face today? Lenses. A Canon digital fullframe cmos sensor is much more demanding than any film quality of the same area. The lenses on market today have a very hard time resolving the details that the sensors can (and the photographers want to) capture. As you increase the area, the glass quality deteriorates and edge sharpness and distortion becomes a problem.

Creating quality glass means 2 problems. Size, better glass is bigger, and price. One way around this is to cram more megapixels into the same area but this creates other problems - noise being the most notable.

One solution is to add more pixels by increasing the sensor area where it is shortest. The 5D sensor is 36 x 24. Add 50% on the short side and you get a 36 x 36 sensor area with added megapixels, without added noise and without putting additional strain on the glass. You can do it in the same body with the same lens mount. Well, not quite since the sensor is optimimzed in central placement. Take away just a bit though and a square format on the same mount is clearly possible.

Personally, this would be a great camera since the perspective of square format is incredibly powerful for certain images. retrack.. What was the hasselblad key selling point in the beginning of film days?

So, the solution, unless you want to force your whole client base to change lens lineup in order to extract detail, would be to maximinze use of the glass area instead of using a rectangular portion of it. But, as you can see from the illustration where pink is your glass, squaring the format alone gives very little additional area.

Want to guess which sensor format the new Canon is? ;)



UPDATE - Canon has launched the 1D Mark III at 10 megapixels and 10 fps with live view and sensor cleaning. More info here.

Suppose you alter the focal distance to the sensor. The illuminated area can be made bigger - but at optically acceptable quality levels?

This is perhaps where we are going. To a more unified distribution of pixels which you can crop in-camera to your preference. On a square format sensor, the word "fullframe" earns its right. On a system where the whole geometry of format - focal distance - lens configuration - and perhaps mount is involved the word "market leader" gets a whole new meaning.

There has been widespread talk of Canon developing a new lens lineup. A MF body with optional crop, much the same as the Nikon D2Xs 12.4 Megapixel Digital SLR Camera would support both formats and perhaps both lens lineups. If you want full quality, you will need the new lenses.

Monday, February 19, 2007