Introduced at the same time as the new CL camera, the Leica Elmarit-TL 18mm f/2.8 ASPH. ($1,295) fills a couple gaps in the system. It's now the widest and slimmest prime lens available, the latter aspect a big plus for use with the compact CL and TL2 mirrorless cameras. But to achieve its size and, in Leica terms, relatively low asking price, there's a drop in sharpness as you move away from the center of the frame. If that's a compromise you're willing to make, the 18mm f/2.8 ASPH. is worth a look. But if you want crisper performance and the convenience of a zoom, the Super-Vario-Elmar-T 11-23mm f/3.5-4.5 ASPH. is a better choice.

Design

We call the Elmarit-TL 18mm a pancake lens because of its fairly flat, circular design. It measures 0.8 by 2.4 inches (HD), weighs just 2.8 ounces, and supports 39mm front filters. There's no lens hood included, but according to Leica that's a feature, not a detriment; The lens is designed to be used without a hood, so you can take full advantage of its small form factor.

The lens is available in black or silver, housed in a metal barrel. The design is understated, with 18 printed at the top of the barrel in yellow print and Leica branding in white surrounding the front element. The signature Leica red dot is placed on the barrel and shows you how to position the lens to mount it to the camera.

There are no switches or controls, save the standard manual focus ring. Manual focus is an electronic affair, so you don't get tactile feedback when adjusting it. The ring turns comfortably, and offers some resistance, to make manual focus adjustments more pleasant.

The minimum focus distance is 11.8 inches (0.3-meter), which is a bit limiting. The lens captures a field of view equivalent to a 27mm full-frame lens, which typically focus to 9.8 inches or so. It's not a huge difference, but you may find yourself backing up a little bit to get a shot.

The lens omits optical stabilization, a feature that's not included with any APS-C lens for the L-mount system. The only stabilized mirrorless lenses currently available from Leica are the full-frame 24-90mm and 90-280mm zooms. They both work with APS-C bodies, but are a bit too large to handle comfortably with the svelte CL and TL2 cameras.

Image Quality

I tested the 18mm with the 24MP Leica CL . It uses the same image sensor as the TL2, so we expect identical performance when paired with Leica's other current APS-C L-mount body.

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At f/2.8 the lens scores 1,649 lines on Imatest's center-weighted sharpness test. That's less than the 1,800 we want to see from a lens. The central area of the frame does show good results (1,983 lines)—but as you move away from the edges details soften. It's not something that's going to kill an image when viewed on a screen, but if you want to make big prints you'll notice it.

Stopping down to f/4 improves overall image quality. The average resolution climbs to 1,751 lines, with a sharp central area that's crisper (2,192 lines) and larger than what you get at f/2.8. Image quality remains fairly steady at f/5.6 (1,783 lines) and f/8 (1,771 lines). Diffraction detracts from resolution at f/11 (1,616 lines) and f/16 (1,347 lines).

The 18mm might not be the sharpest lens in your toolkit, but it does deliver in other areas. Distortion is controlled: We see about 0.9 percent of the barrel variety, which is negligible in the field. Illumination is even across the frame from f/4 onward, and even at f/2.8 the corners only lag behind the center brightness by -1.2EV. That's outside our -1EV tolerance, but just barely. Finally, I can't find any evidence of color fringing caused by chromatic aberration in images, even in areas of high contrast towards the edge of the frame, where they are likely to appear.

Conclusions

The Leica Elmarit-TL 18mm f/2.8 ASPH. is one of the smallest, lightest mirrorless lenses available for any APS-C system. That alone makes it desirable, especially when paired with the CL or TL2 ($1,950.00 at GoldenMine) , for days when you want to carry a light kit. It does make some optical compromises to get there, typical of a wide-angle pancake. Leica gear is expensive when compared with competing systems, but the Elmarit-TL is the least expensive lens you can get for its mirrorless system, and can be had at a discount when bought along with the CL body. We like it for its size and wide angle field of view, even if it doesn't deliver sharpness up to the edges of the frame. If that's what you're after, spend a bit more on the larger 11-23mm zoom.

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