9/10/2009 - Updated with tests of the M9 sensor's infrared response compared to the M8.

Three years ago Leica revealed the M8, its first digital rangefinder.  The M8 looked similar to the film M7 but was a completely new body, with a 27 x 18 mm (1.3x FOV crop) 10 megapixel Kodak CCD sensor and no resolution-sapping anti-alias filter.  However it wasn’t all plain sailing, all modern digital cameras feature a glass UV/IR filter in front of the sensor, and in the case of the M8 the design was particularly thin (just 0.5 mm) which turned out, in production, not to be strong enough.  We along with several other testers noted this issue, and soon Leica were producing screw-on UV/IR filters for their lenses in order to eliminate the effects of such spectral pollution.

In September 2008 came a subtle update; the M8.2 was identical from a sensor and imaging sub-system point of view but added a few new features; a quiet metal shutter, discrete shutter re-cock, snapshot mode, sapphire crystal cover glass for the LCD and most importantly the ‘stealthy’ black Leica dot.

And now comes the M9, 'the world's smallest full frame camera', which on paper at least looks to be the ultimate digital M; an 18 megapixel full-frame (36 x 24 mm) sensor, still with no low-pass filter but now with a new UV/IR cover-glass filter which means no need for lens filters. Here are some salient image quality related points which came out of an interview we conducted with Leica in Solms:

  • A stop improvement in noise (ISO 1250 M9 = ISO 640 M8) - this comes from a range of significant re-engineering efforts - the sensor is effectively a scaled up version of that found in the M8 (the photosite architecture and pitch remain the same) but it has a different CFA dye to improve red sensitivity, the output stage has been improved, the signal paths have been shortened (new PCB design), two processors are now used for improved JPEG quality (and speed) and the firmware was written from scratch with improved noise reduction.
  • 'Negligible' difference in corner fall-off between the M9 and M8 - the new microlens layout has increased offset at the corners to keep the effects of shading to a minimum. There is no limitation on the lenses which can used, even short back-focus ultra-wide angle designs will work without issue (we tested the M9 with the 16 / 18 / 21 mm Tri-Elmar-M and saw no obvious corner problems).
  • New UV/IR filter cover glass - the M9's sensor now has a 0.8 mm UV/IR filter, which is not only thicker than that on the M8 but also made from a new material with improved IR cut-off properties (I'm sure Leica are happy to put that episode behind them).

Leica M9 vs. M8 / M8.2

  Leica M9 Leica M8 Leica M8.2
Sensor • 36 x 24 mm CCD
• 18 million effective pixels
• 6.8 x 6.8 µm pixel pitch
• No anti-alias filter
• 27 x 18 mm CCD
• 10.3 million effective pixels
• 6.8 x 6.8 µm pixel pitch
• No anti-alias filter
Sensor FOV crop None (1.0x) 1.3x
Sensor UV/IR filter 0.8 mm (no lens filters required) 0.5 mm (required additional lens filter)
Processors Dual Single
Sensitivity range ISO 160 - 2500 (ISO 80 'pulled'*) ISO 160 - 2500
Lens selection Auto or Manual (database) Auto or Off
Bright-line frames 35 & 135 mm, 28 & 90 mm, 50 & 75 mm 24 & 35 mm, 28 & 90 mm, 50 & 75 mm
Frameline optimization 1.0 m 0.7 m 2.0 m
DNG Uncompressed or compressed Compressed
Color spaces sRGB, Adobe RGB sRGB, Adobe RGB, ECI RGB
Metering Center-biased reflected from white & grey stripes on shutter blades Center-biased reflected from white stripes on shutter blades
Exposure bracketing Yes, 3/5/7 images, 0.5 - 2.0 EV None
Exposure compensation Menu or rear dial Menu
Shutter Quiet metal blade Metal blade Quiet metal blade
Shutter speed 32 - 1/4000 sec 32 - 1/8000 sec 32 - 1/4000 sec
Flash sync 1/180 sec 1/250 sec 1/180 sec
Shutter release Standard / Soft / Discreet Standard / Discreet
Continuous shooting 2 fps, max 8 images 2 fps, max 10 images
Self-timer Off, 2 sec, 12 sec 2 sec, 12 sec
B&W modes B&W, Vintage B&W B&W
User profiles 4 3
Snapshot mode Preset user profile None Mode dial
White balance Auto, 7 presets, Kelvin, Manual Auto, 6 presets, Kelvin, Manual
ISO setting Dedicated button Menu
Information display On main LCD only Small top-panel LCD and main LCD
LCD monitor 2.5" 230,000 pixels 'brighter output' 2.5" 230,000 pixels
LCD cover glass Perspex Sapphire glass
USB mode PTP or Mass storage device PTP
Menu languages 8 7
Folder management Select / Create / Reset None
Body finishes Steel gray, Black Silver, Black
Leica 'dot' color Red Black
Bundled software Adobe Lightroom 2 Capture One LE

* This is effectively over-exposed ISO 160 which is then pulled down a stop by a different tone curve, it’s indicated as “PULL 80” and will have less dynamic range than ISO 160

Solving the corner vignetting problem

Because a rangefinder camera doesn't have a mirror box its lenses don't have to be retrofocus in design, meaning they can sit much closer to the film (or in this case the sensor). The problem with this comes with wide angle lenses (which are pretty much the main staple of the rangefinder camera). Towards the corner of the frame the angle of incidence of the light rays coming from the rear of the lens can be so severely off-perpendicular that they won't pass equally through the microlenses above the sensor, which can lead to fairly strong vignetting. Even a modest wide angle lens at this kind of distance could produce a difference of a stop or two between the center of the frame and the edges using a standard CCD sensor.

The M8 had a 27 x 18 mm (1.3x crop) sensor and some thought it simply wouldn't be possible to use a full-frame (36 x 24 mm) sensor on a rangefinder, but Leica appear to think otherwise. Their approach is the same as for the M8; use offset microlenses (instead of placing all microlenses directly over the photodiode they are gradually offset as you get closer to the edge of the frame - see below) and to know which lens is being used and apply some software correction.

Below is a diagram provided by Leica which does some way to explaining how microlenses at the edge of the frame are offset from the photodiode below them, compared to a normal microlens / photodiode combination in the center of the frame.

Rangefinder advantages / disadvantages (for the uninitiated)

  • Fewer moving parts (no mirror or diaphragm) means slower shutter speeds possible (-2 EV)
  • More compact, discrete and quieter than an SLR
  • Shorter shutter lag
  • Lenses are considerably smaller than an equivalent SLR lens
  • No auto-focus makes them less suitable for action shots (or at least doing so requires a lot more skill)
  • Many users claim rangefinder focusing is faster than using a focusing screen
  • Rangefinder
    • You are not looking through the lens itself and do not have a focusing screen hence it is more difficult to get a sense of depth-of-field
    • Framelines indicate the field of view of different lenses
    • Because there is no mirror you have no mirror black-out
    • Brighter than any SLR viewfinder, and not affected by lens maximum aperture
    • Not as accurate as an SLR viewfinder, especially with longer lenses (or close subjects)
  • Longer minimum focus distances compared to an SLR
  • Virtually no telephoto lenses beyond 135mm
  • Very wide angle or telephoto lenses require an accessory viewfinder, meaning focus and framing are separated

Leica factory tour

Don't miss our factory tour article which includes a description of the assembly of the M9.

A brief history of the M series

Leica introduced the first M series camera, the M3, at Photokina in 1954, which was the first Leica rangefinder body with a bayonet interchangeable lens mount. It marked the beginning of a legendary series of cameras and lenses, the latest of which (the M7) is one of the few 35 mm rangefinder cameras still in production. For over half a century Leica has resisted the temptation to change the essential simple design established with the original M3 (it wasn't until 2002 that an electronically-controlled shutter was introduced allowing aperture priority automatic exposure).

With an average 10 years between major upgrades and many of the original M3s still in regular use, the M platform is felt by its legion of fans to be the purest photographic tool available, and a welcome antidote to the mass of plastic feature-laden models that make up the rest of the market. Owning a Leica M camera has always been something people do with their hearts as much as their heads - and some of the most famous images of the 20th century's greatest photographers were taken using them.

Leica M series History (brief)

  • M3 (1954 - 1966)
  • MP (1956 - 1957)
  • M2 (1958 - 1967)
  • M1 (1959 - 1964)
  • M4 (1967 - 1975)
  • M5 (1971 - 1975)
  • CL (1973 - 1976)
  • M4-2 (1977 - 1980)
  • M4-P (1980 - 1986)
  • M6 (1984 - 1998)
  • M6J (1994)
  • M6 TTL (1998 - 2002)
  • M7 (2002 - )
  • MP (2003 - )
  • M8 (2006 - 2008)
  • M8.2 (2008 - 2009)
  • M9 (2009 - )

Full disclosure - personal bias

Before the M8 review I had no experience of rangefinder photography, something I considered relegated to history.  During the review process (and thanks to input from those who had used rangefinders before) I gradually began to ‘get’ the advantages, being better ‘connected’ to the subject thanks to the huge bright viewfinder, and being forced to focus manually, alwys select the aperture, and think more about the shot. Not to mention in the case of the M8, the look from those gorgeous prime lenses (amazingly sharp at the point of focus fading smoothly to silky bokeh).  Hence not long after posting my review I bought an M8 for myself (along with a bunch of lenses), and ever since (and unconsciously) all of my personal favorite photographs have come from the M8.

Obviously M series ownership isn’t for everyone, nor is rangefinder photography.  But if you’re serious about photography and you get the chance, even if you’d never considered it before, you really should try it.