Image Quality

Shooting a rock show with a rangefinder is a bit like trying to ride up Mont Blanc on a unicycle. You can do it, and maybe one of the people who sees you trying might think you're pretty cool, but there are easier ways of getting to the top of a mountain.

35mm F1.4 Summilux ASPH. F2.8 (ish), ISO 6400. (Converted from Raw)

Auto ISO

I mentioned earlier that I tend to keep manual ISO dials locked to ‘A’. Some Leica users will cry foul at this, but I’m primarily an aperture-priority shooter, and I enjoy the luxury of only having to worry about one exposure variable. Also, I'm lazy. But this only works if the Auto ISO setting is actually useful. Fortunately, Leica’s automatic ISO system works very well. A simple 1/FL option is a good starting point, whereby the camera will stick to shutter durations shorter than (for example) 1/30 sec when using a 35mm lens. In addition, 2/FL and 4/FL options provide more insurance against shaky hands or faster-moving subjects, and you can also pick your own specific maximum exposure time from 1/500 sec down to 1/2 sec.

Image quality is superb across the M10’s standard ISO sensitivity range of 100-6400

Of course, the X/FL modes rely on the M10 knowing the focal length of whatever lens you’re using. Modern M-series lenses are '6-bit coded', which means that the M10 can recognize their focal length and maximum aperture (albeit not the aperture you’re shooting at, hence the 'ish' noted in my image samples in this review). If you’re using an older lens, or a third-party one which isn’t 6-bit coded, you can enter its focal length manually in the menu system. If you don’t swap lenses much this is very straightforward, but if you shoot with a wide selection of older glass, it’s something to bear in mind. Auto ISO works in manual exposure mode, as well as aperture priority.

'Newly Developed' Sensor

Speaking of ISO sensitivity, the M10 has a new base ISO of 100, courtesy of its 'newly developed' sensor.

Leica won’t be drawn on the exact details, and we can’t perform in-depth lab testing on our late pre-production camera, but it certainly seems better than the 24MP sensors in the Typ 240 and the Q. At low ISO sensitivity settings there’s no banding, even when files are pushed considerably, and image quality is superb across the M10’s standard ISO sensitivity range of 100-6400.

At low-medium ISO sensitivity settings, the M10's 24MP sensor delivers excellent resolution. And compared to some previous M-series models, its shutter is very discreet - certainly discreet enough to use in a library.

35mm F1.4 Summilux ASPH. F2.8 (ish), ISO 500. (Converted from Raw)

The M10's center-weighted metering system is a little prone to underexposure when there are strong light-sources in the scene. I set +1/3EV exposure compensation for this low-light shot but ended up pushing it further in Photoshop.

35mm F1.4 Summilux ASPH. F1.4, ISO 12,500. (Converted from Raw)

Leica claims around 13 stops of Raw dynamic range and anecdotally, this is backed up in my use of the camera so far. We don’t know yet whether the M10’s sensor is technically ISO invariant but I have found that in Raw mode I can shoot the M10 in the same way as I tend to shoot the Nikon D750 in contrasty conditions - expose for highlights, and pull the shadows up later, without needing to worry about a lot of noise or banding spoiling the view.

This shot was not taken to deliberately test the M10's sensor, I just messed up the exposure.

I shot in JPEG+Raw, and right now you're looking at the out of camera JPEG.

If you look really closely at the lower-middle shadow area, you might be able to tell that there's a dog in there...

35mm F2 Summicron ASPH. F4 (ish), ISO 100.

Do you see it now? This is the simultaneously-captured Raw file, pushed by 3.5EV in Photoshop. As you can see, even after a fairly aggressive exposure push, there's very little penalty in terms of image quality loss in what had been areas of deep shadow.

We'll expand this section of our review when we have access to a fully reviewable M10. For now though, we're impressed.