By Claus Possberg

Freely translated into English by Michael Reichmann

During the recentNature Photo Daysexhibition in Germany I had the opportunity to try out one of the 40 preproduction units of the Mamiya ZD that are currently (early June 2005) available for testing. The very nice people at Mamiya in Munich were also very patient in answering my questions. This camera is the first completely integrated digital medium format camera – not just an adapted digital back solution.

The body tested appears to be almost full production quality, at least as far as features, functions and build quality are concerned. I found the handling to be quite good, with the large body fitting comfortably in my relatively large hands. The weight is within a few grams of the Canon 1Ds MkII, and the Mamiya even a breath narrower. That is amazing, considering that the sensor, mirror and prism are nearly twice as large.

On the left side of the body are slots for two seperate memory cards (CF and SD) just as with the Canon. Which card is used can be selected via menus. In the base, under the handle grip, is found the rechargable Lithium Ion battery. This is a Sony video battery which can be purchased everywhere. Mamiya is claiming that the battery should be good for 450 exposures, though actual field results remain to be seen.

The viewfinder is better than most small format SLR, but not quite as super-bright as the Mamiya AF645D. In the viewfinder, beneath the matte focusing screen, the usual LED information display is found and it is quite visible. A viewfinder diopter adjustment is found beside the viewfinder. The two LCDs can be illuminated with a soft green-blue light and are easily readable in the dark. Here the usual data (image size, format, compression ratio, picture number, ISO, selected memory card, white balance etc.) are shown. The menus are viewed on a 1.8"color monitor, which is sufficiently bright, but rather small and only of medium resolution. Mamiya claims that power saving is the reason for this design decision. The menus are arranged into four different color groupings, and are well structured. Menues can be displayed in several languages. The adjustment possibilities are rich and clearly arranged and the functions are highly customizable. 31 Presets can be produced and stored separately. Menu selections are made with two scroll wheels and are achieved very quickly. Especially practical is the exposure shift function which can be used with the Program exposure mode, where pairs of aperture / shutter combinations can be scrolled through quickly.

Inside the camera is a 36.1 x 48.1mm sensor from the Canadian chip maker Dalsa. Individual pixels are square and 9×9 microns in size. The sensor diagonal is 60.1mm. Since the 645 film format is nominally 56.0 x 41.5mm, producing a diagonal of 69.7mm, the ZD therefore has a magnification factor of 1.16x. At present the shortest focal length available, the Mamiya AF 3.5 / 35mm, corresponds on the ZD to a 24mm lens on a full-frame 35mm camera. Mamiya is apparently thinking about bringing out an AF 28mm lens, which would correspond to a focal length of 19mm in 35mm format terms.This would meet my needs in outdoor photography very well. As for other focal lengths, all autofocus lenses for the Mamiya AF645/AF645D are also usable on the ZD. The autofocus worked sufficiently quickly (noticeably faster than on the AFD), while only the 300mm lens was slower – probable a firmware problem with the preproduction ZD. The shutter works after focusing practically delay-free. Storing the large amount of data produced by the 22MP chip takes about 8 seconds to fill the internal memory buffer, which holds 11 frames, and which can be filled at the rate of 1.4 frames / second. To flush the full buffer of 385MB takes about 80 seconds on a 1GB Transcend 40X card, used for testing. Thus, writing each file to the card takes about 6-8 seconds.

It is interesting that that the camera comes without a low-pass filter. Instead an Infrared cut-off filter is provided, which can be user removed. An extra available Low Pass filter for photographs of objects with regular, fine structures can be alternatively used to prevent Moire. I find this to be a very good solution, because LP filters tends to soften images, and with photos of people or landscapes is completely redundant. The removable filter also helps to keep the huge sensor clean, because the filter can be taken out for cleaning if necessary. Interestingly, all current DSLRs use fixed LP filters.

A Firewire port is provided as well as video out (PAL or NTSC). The camera can be remote controlled with a Mac or Windows computer.

I found the image quality to be unbelievably good – comparable to high-end drum-scanned 6×7 transparencies. Unfortunately, as is common with pre-production cameras I am not able to provide you with samples.

High quality JPGs with 64 MB of uncompressed image data (8 bit) shrink to about 10 Mbyte on the memory card. The Mamiya’s RAW data format MEF comes in at 34.9 Mbyte. Regretably Mamiya has not adopted the advantages of an open RAW standard, producing yet another proprietray raw format.

The ZD offers sensitivities from ISO 50 to 400. The sensor seems to be sensitive to color noise, but with a program such asNoise Ninjacan easily cleaned up. I therefore vote for 800 and 1600 ISO as well, preferably without the overdone smoothing which Canon uses to achieve "low-noise" at high ISOs.

According to Mamiya the sensor’s data is processed internally as 14 bits per color channel and then recalculated to 12 bit depth. I would suggest to Mamiya that they make the full 14-bit data also available,andin DNG format.

And, while I’m asking for features. I would like the possibility of being able to update the mask for dead pixels. On such an enormous chip area there will naturally accumulate hot / dead pixels over the course of time. A user initiated "black exposure" could serve as a renewed mask in order to recognize and replace bad pixels by averaging values from neighbouring pixels. It would also be useful to integrate mirror lock up with a 2 second self-timer, without the need to use the cable release.

The price of the Mamiya ZD is not final yet, but will hopefully be about 10,000 EURO, or US $12,000. Series production could start this summer. A pre-production build of 40 cameras is currently with selected Japanese photographers to assist in optimizing the camera prior to production. I hope to see the ZD in production soon, because without it I believe that Mamiya does not have a very certain future.

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The Future

With further improvements in sensor technology and internal data processing the ZD system has room for growth, while the best 35mm DSLRs are near the limits of overall quality and maximum resolution, especially with regard to available lenses – primerily wide angles. This is shown by independent tests and my own experience again and again. In future there is plenty of room for a Mamiya ZD MkII with 40 MP sensor and numerous other enhancementgs perhaps over the next 2-3 years. Who is to build such a camera, if not Mamiya? Pentax is still in early days with its wooden design mock-ups and an 18 MP sensor. All the other medium format camera makers are now gone, except for Hasselblad.

I will buy the ZD immediately as soon as it becomes available. I find it to be almost ideal, with optimal image quality and appropriate for outdoor as well as studio applications. It has the 4:3 aspect ratio preferred by many pros, rather than the 3:2 format of 35mm. Only when it comes to fast action sports will the ZD not be the ideal choice.

The concept is amazing, the handling is simple (with 110 Raw pictures and / or 500 high quality JPGs on a 4 GB card), and the existing lens range (at present 35 to 300mm including 2 zooms and a macro lens) is first-class. The photo above shows a mini photo backpack with the ZD and a focal length assortment of 35-300mm. At scarcely 5 kg the whole kit is very well suited for travel. I’m eagerly awaiting a production camera. Well done, Mamiya!

By Claus Possberg

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Dr. Claus Possberg, MD, is a radiologist, living in Germany, who owns his own clinic with 23 employees.

Claus is 46 years old and has been a photography enthusiast since the age of 14. As a university student he bought his first SLR, a Pentax ME Super in 1978, processing his B&W photographs in a bathroom darkroom. For the past 5 years he has been using 6×7 equipment (Mamiya 7 II and Pentax 67II).http://www.possi.de/)

The original version of this article, in German, is available athttp://www.possi.de/fotografie/mamiyazd.html

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