In summary
The Summilux-TL 35mm f/1.4 ASPH lens fulfils its objectives as a fast prime lens for Leica’s L-mount camera bodies. Its build quality is up to the company’s traditional high standards and when used within its limitations it can produce sharp, high quality images, particularly if you shoot raw files.
For most of the aperture range, resolution remains high and images are sharp and detailed. The lens is also virtually distortion-free. The internal focusing mechanism makes it relatively quiet to operate and offers potential for very fast autofocusing.
Full review
The Leica Summilux-TL 35mm f/1.4 ASPH was announced 29 October 2015 as the fast standard prime lens for the company’s cropped (APS-C) sensor cameras, where it covers a 35mm equivalent focal length of 52.5mm. It is compatible with all L mount cameras, including the T-series and SL-series, the latter when used in APS-C crop mode. The anodised metal body of this lens is available in silver or black and supports 60 mm filters.
The two colour options for the Summilux-TL 35mm f/1.4 ASPH lens, shown with the lens hoods fitted. (Source: Leica Camera.)
The optical design of this lens uses 12 elements, four of which are aspherical, arranged in eight groups. The position of the aspherical element group is shown in the diagram below.
The optical design of the Summilux-TL 35mm f/1.4 ASPH lens. (Source: Leica Camera.)
Beyond the optical diagram shown above, Leica doesn’t provide much in the way of technical information about the inner workings of this lens. We don’t know what type of AF drive motor is used, nor does the diagram show which elements are moved during focusing, although we know from using the lens that focusing is internal. There’s also no information on lens coatings (although we assume a lens at this price would have them).
The specs sheet states the ‘distance setting’ is electronically controlled and says users can select between Automatic (AF) and manual (M), with manual override possible in AF mode at any time via the setting dial. Aperture settings are also electronically controlled, again via dial adjustment on the camera.
The lens has only one control surface: the focusing ring. There’s no distance scale and no depth-of-field indicator. The lens hood (which wasn’t supplied with the review product) adds 46 mm to the overall length of the lens and 11 mm to its diameter.
Who’s it For?
The simple answer is: anyone with a Leica L-mount camera. Given its ‘TL’ designation, this lens has been designed for the T-series cameras, which have APS-C sensors. When fitted to an SL-series camera, it requires the camera to use the cropped sensor-format. This works well for photographers who shoot video with the SL, which uses an APS-C sized area in the centre of the full-frame sensor when recording 4K movie clips.
An important feature of this lens is its wide (f/1.4) maximum aperture, which enables photographers to shoot with the camera in low light levels. Unfortunately, in practice we found the lack of stabilisation in either the camera or the lens resulted in camera shake when hand-held shots were taken at shutter speeds below 1/20 second. In contrast, cameras with stabilisation can usually be hand-held at 1/10 second or slower.
On the positive side, the combination of the effective focal length with the f/1.4 maximum aperture provides plenty of scope to control depth of field for selective focus applications. Internal focusing also means the front of the lens doesn’t rotate during focusing, allowing for easy use of polarisers and graduated filters.
Build and Ergonomics
It goes without saying that Leica products are renowned for their superior build quality and the Summilux-TL 35mm lens is no exception. The barrel is made from solid metal, with a 40 mm wide focusing ring covering roughly half of its length.
Side view of the Summilux-TL 35mm f/1.4 ASPH lens without the lens hood. (Source: Leica Camera.)
The ring is located 15 mm behind the front edge of the lens barrel and 10 mm back from the bayonet fitting for the lens hood. A 32 mm wide strip of fine, moulded ribbing around the middle of the ring provides a decent grip surface.
The focusing ring rotates through 360 degrees when power is off and turns smoothly when power is on, engaging a motor that moves the focusing elements. Rotation is well-damped, providing a slight resistance when the ring is rotated, a little like using a mechanically-driven lens. Manual focus over-ride in AF mode is supported.
The lens barrel continues for 13 mm behind the focusing ring and then steps in to a thin, glossy metal ring that marks the edge of the solid metal mounting plate. There’s no rubber sealing between the lens and the camera body, indicating the lens isn’t weatherproof (nor is the TL2 camera). Ten metal contacts inside the mount provide connections to the camera.
Performance
The review lens performed well on the TL2 body we used for our tests. We carried out our usual tests with JPEG files but also captured raw files as part of our testing of the TL2 camera and the results can be seen in that review.
Our Imatest tests showed the highest resolution was at f/4.0, which is three stops down from the maximum aperture. However, for the central third of the frame, resolution remained above 3000 line widths/picture height all the way from f/1.6 to f/7.1, inclusive, falling just short at f/1.4 and f/8. This is reflected in the amount of detail captured in image frames.
Edge softening was measured towards the periphery of the frame but, as expected, it was reduced as the lens was stopped down. Diffraction begins to reduce resolution a little at f/8 but is well entrenched by f/11, although images are still sharp enough for some applications at f/16 (the smallest aperture). The graph below shows the results of our tests.
Unusually for a modern camera, the Leica TL2 we used appears to lack any processing to correct chromatic aberration in JPEG files. As a consequence, our Imatest graph shows it to be well into the ‘low’ band and reaching into the ‘moderate’ band at the widest aperture settings. In the graph of our results below, the red line separated the ‘negligible’ and ‘low’ bands, while the green line marks the lower edge of the ‘moderate’ band.
We found some coloured fringing in test shots taken with the TL2. We don’t see this as a major problem, partly because all Leica cameras support raw file capture using the ‘universal’ DNG format, which can be used in virtually any processing software. Converting the raw files from our tests into TIFF format with Adobe Camera Raw enabled us to use the software’s automatic corrections, which brought the readings down to ‘negligible’ levels.
The lens handled strong backlighting very well and was virtually immune from veiling flare. No flare artefacts were found in any test shots.
The wide maximum aperture provided plenty of scope for differential focusing, particularly in dim lighting. Bokeh (out-of-focus softening) was generally smooth at wide apertures with low contrast scenes. However, brighter out-of-focus highlights were prone to outlining, which interrupted backgrounds that would otherwise have appeared relatively uniform.
Conclusion
The Summilux-TL 35mm f/1.4 ASPH lens fulfils its objectives as a fast prime lens for Leica’s L-mount camera bodies. Its build quality is up to the company’s traditional high standards and when used within its limitations it can produce sharp, high quality images, particularly if you shoot raw files.
For most of the aperture range, resolution remains high and images are sharp and detailed. The lens is also virtually distortion-free. The internal focusing mechanism makes it relatively quiet to operate and offers potential for very fast autofocusing.
Although its minimum focusing distance of 40 cm provides little scope for close-up shooting, with appropriately-sized subjects, the f/1.4 maximum aperture can deliver attractive pictures in optimal conditions.
Leica’s listed price for this lens is AU$3350 but if you shop around you’ll probably find it for less than AU$3000. B&H has it listed at US$2395, which converted to AU$3026.80 when this review was published. To that you’ll have to add roughly AU$60 for the cheapest shipping plus ‘Duties and Tax’ of roughly AU$450 so you’d be better off buying from a local Leica Boutique or specialist re-seller.
SPECS
Picture angle: 45 degrees
Minimum aperture: f/16
Lens construction: 12 elements in 8 groups (including 4 aspherical elements)
Lens mounts: Leica L bayonet (suits all Leica T and SL models)
Diaphragm Blades: 9 (circular aperture)
Focus drive: Electronically controlled (motor type not specified)
Stabilisation: No
Minimum focus: 40 cm
Maximum magnification: 1:9.4
Filter size: 60 mm
Dimensions (Diameter x L): 70 x 77 mm
Weight: 128 grams
Standard Accessories: Lens front and end caps, lens hood
Distributor: Leica Camera Australia, (03) 9248 4444, http://en.leica-camera.com/
TESTS
Based upon JPEG files captured with the Leica TL2 camera.
SAMPLES
Vignetting at f/1.4.
Rectilinear distortion.
ISO 320, 1/100 second at f/1.4.
ISO 3200,1/100 second at f/5.6.
Close-up; ISO 100, 1/250 second at f/2.2.
ISO 100, 1/500 second at f/5.6.
Crop from the above image at 100% magnification showing details near the centre of the frame.
Crop from the above image at 100% magnification showing details near the edge of the frame.
Strong backlighting; ISO 100, 1/1000 second at f/8.
Strong backlighting; ISO 100, 1/1600 second at f/6.3.
ISO 100, 1/250 second at f/6.3.
Crop from the above image at 100% magnification showing coloured fringing.
No flare; ISO 100, 1/1600 second at f/6.3.
Bokeh at f/1.4, 1/500 second at ISO 100.
ISO 100, 1/500 second at f/5.6.
ISO 100, 1/320 second at f/6.3.
ISO 100, 1/1000 second at f/5.
ISO 100, 1/200 second at f/6.3.
ISO 100, 1/125 second at f/11.
ISO 100, 1/400 second at f/4.
ISO 100, 1/160 second at f/1.4.
ISO 100, 1/400 second at f/3.5.
Additional image samples can be found with our review of the Leica TL2 camera.
Rating
RRP: AU$3350; US$2395
- Build: 9.0
- Handling: 9.0
- Image quality: 9.0
- Versatility: 8.6