I've never been a big Leica fan: while its cameras' photo quality is great and they feel like tanks, the cameras always felt stubbornly anti-tech and too quirky for their price britches. I only put this out there for context so that when I say that the Leica Q is the first Leica I have ever wanted and that I hated having to give it back after a mere five days of testing, it's not hyperbole.
At $4,250 I'll never own one, but this full-frame, fixed-lens "compact" incorporates all of Leica's traditional quality and aesthetics without forgoing the modern features many of us lower-level beings want, like autofocus, optical image stabilization, a touchscreen and Wi-Fi.
When I reviewed the first camera in this class, thein March 2013, I dubbed it "a pricey slice of heaven." The Leica Q is really a pricier slice of heaven. In the UK, the Q will cost £2,900 and will go on sale this week. I don't yet have prices for Australia, but that $4,250 price tag converts to about AU$5,500.
The Leica Q's photo quality is, of course, terrific; however, Leica's processing decisions and options are not as mainstream as its feature set. You should probably always shoot DNG+JPEG, because the JPEGs have minimal processing and you'll want to edit the DNGs.
Photos display broad dynamic range with accurate but saturated colors, though in its default settings the Standard contrast option will blow out the highlights and shadows of JPEGs. You can always pull them back by editing the raw image. Leica's home-grown, OLPF-free 24-megapixel sensor has very fine-grained color noise through ISO 12500, and combined with Leica's processing the photos retain a lot of detail up through the top of the range, ISO 50000.
Leica doesn't perform any noise smoothing in the JPEGs, however, so the photos look grainy starting at about ISO 6400. I prefer this approach, but it won't be to everyone's taste, as it's different from what we've come to expect from most cameras. Additionally, at the two highest ISO sensitivity settings horizontal striations appear in the noise. If that's a problem for you, I'd wait to see if it's something Leica can (and will) address with a firmware update. It would be great if the camera had some options for the JPEG processing, as just a little smoothing would help at the higher sensitivities.
The 28mm f1.7 lens delivers beautiful bokeh, with smooth out-of-focus areas and round highlights. It displays excellent sharpness, across the entire aperture range and from edge to edge, with little fringing. Although Leica warned me that the optical image stabilization could degrade the corners somewhat,not an uncommon problem, but I didn't see any issues. If you do, you can turn it off.
All that's great; the moire, not so much. (Moire is an interference-pattern artifact that appears in high-frequency patterns, like fabric, as shown below.) It's everywhere. Normally, I have to search for examples of it in my photos, but for the Q I had to narrow down an example from a wealth of choices. While I expect it with a sharp lens and an antialiasing-filter-free sensor, the camera should at least offer some moire reduction for the JPEGs.
The video looks great as well: sharp and relatively noise-free in low light. It's a bit too contrasty, but you can fiddle with that in the settings. The continuous autofocus doesn't work very well here -- it's easily distracted -- but with the viewfinder manual focus works extremely well.
Given Leica's relative lack of experience with autofocus systems, the Q acquits itself very well. It powers on, focuses and shoots in under a second; it's extremely tough to accurately measure startup time because of the camera's design. In practice, though, it never slowed me down and never missed a shot waiting for it to start.
It takes 0.2 second to focus and shoot in good light and 0.3 in dim, good performance for this type of camera, as is its 0.4 second time to shoot two consecutive photos in both JPEG and DNG+JPEG formats.
Continuous shooting speed with autofocus for JPEGs is great for its class. In testing it sustained a rate of 4.7 frames per second for over 30 shots. While it can burst DNG+JPEG at 5fps, it can only do it for nine shots before slowing. The camera doesn't offer a raw-only mode.
The tracking autofocus is a little rough, though. Like most older contrast-autofocus systems, the focus areas are in the center of the frame and it loses the subject easily. However, using center-area autofocus and panning I got a reasonable number of in-focus shots, and it locked focus quickly while street shooting. Its manual focusing is everything you'd expect: smooth and easy, with accurate focus peaking to aid you.
(Although the Sony and Panasonic cameras I've listed here aren't serious competitors for the Q, I've provided the numbers for context in fixed-lens enthusiast compacts. I haven't tested the Sony RX1R.)