Leica’s new M Monochrom (246)

Leica Monochrom 246

Leica Monochrom 246

Leica’s new M Monochrom (Typ 246) was introduced in May.

We spoke with Jesko von Oeynhausen, the Leica M Monochrom Product Manager.

Jon: The previous Monochrom had a CCD sensor. This one has a CMOS sensor. What is the difference?

Jesko: There are many differences. The sensor for the Leica M (Typ 240 and 246) was designed and constructed by Leica and CMOSIS especially for photography with Leica M-Lenses. The actual sensors are manufactured by one of France’s largest semiconductor suppliers. The precision integration of the sensor in its ceramic housing and the installation of the cover glass are carried out in Germany.

Thanks to the use of only one cover glass instead of three, the number of air-to-glass surfaces is reduced from six to only two. This means that less light is absorbed, fewer reflections occur, and more light can reach the sensor. On top of this, the cover glass used for the sensor in M-Cameras is also multi-coated to reduce reflections.

One of the key prerequisites for optimum imaging performance when using M-Lenses is the minimization of the number and thickness of any layers of glass that could negatively affect the passage of light. Typical sensors currently used in cameras made by other manufacturers usually have several layers of glass in front of the sensor: for example an IR cut filter, a low-pass filter, and a cover glass as well. These additional layers of glass, with a total thickness of several millimeters, leads to unsatisfactory imaging performance everywhere except at the center of the frame, particularly when using wide-angle lenses. This is why we use only an IR cut filter with a thickness of less than one millimeter in the construction of the Leica M and dispense with any other layers of glass. This ensures that we can make optimum use of the full imaging performance of all Leica M-Lenses. We feel that this leads to significantly better imaging results with M-Lenses on the Leica M than with other full-frame cameras, especially with wide-angle lenses.

A particularly flat pixel architecture makes it possible to position the light-sensitive area of each pixel much further forward. This means that each individual pixel can capture light from all directions and at large angles of incidence. What’s more, microlenses gather even more light. Thanks to smart sensor design, more space is also available for each individual pixel.

The sensors of most digital cameras are equipped with a low pass filter. Such filters are installed to prevent moiré effects, which create patterns that look like swirls of lines, and smear the finest structures. This smearing effect, however, also means that the full resolving powers of the lens can not be exploited. This, in turn, has negative effects on image contrast and clarity. Because the sensor of a Leica M has no low-cut filter, it enables noticeably higher resolution and much brighter and clearer pictures.


Why it is the M Monochrom sharper than the color version of the M-System?

Because the monochrome sensor does not use a Bayer color filter array to derive color, there is no interpolation needed to see the lens’ image. With a monochrome sensor, you capture real 24MP information. If you use a color sensor for B/W photography, you have to interpolate 50% of the pixels; for red and blue parts of the image you interpolate 75% of the pixels. Honestly, this sounds worse than it is, because the interpolation algorithms of RAW software processors like Lightroom are so good that you have to dig deep into the pixels to find the difference. On the other hand, if you use an M Monochrom, you are blown away by the sharpness of most of your images.

The difference is very obvious if you use in-camera JPEGs. The M Monochrom JPEGs are also real B/W non-interpolated data. In-camera JPEGs of color cameras lack a lot of detail compared to RAW images. The sharpness advantage of the M Monochrom becomes even more significant when you look at high ISO images. First of all, you gain 1-2 f-stops of sensitivity (and so the noise level is lower) because you are not filtering light with the color filters on the sensor. Also, you maintain fine grain because there is no interpolation blurring the noise; this makes the images much nicer and sharper. And finally, you have no color computation and white balance that additionally adds noise. In the M Monchrom there is no noise filtering necessary, which also results in sharper images.

What is the maximum recommended ISO?

ISO 12,500. We also provide ISO PUSH 25,000 which is also usable in most cases, but postprocessing might be limited by some side effects.

Video files are what format?

Motion JPEG Quicktime 1080p at 24 or 25 fps—recorded onto the internal SD-card.

Leave a Comment

Tags: , , ,