Laowa ‘C-Dreamer’ 7.5mm f/2 MFT lens
The compact size, light weight and f/2 maximum aperture are the ‘wow’ features of this lens, regardless of which version you choose. The build quality and general usablility of the auto aperture version make it our preferred choice.
The Laowa 7.5mm f/2 MFT is claimed by its manufacturer, Venus Optics, as the widest f/2 low-distortion lens ever designed for Micro Four Thirds Cameras. Compatible with Panasonic, Olympus and Blackmagic cameras it comes in two colours, black and silver, and three versions: standard, lightweight and auto-aperture. The lightweight and auto-aperture versions weigh only 150 grams, allowing them to be used in drone cameras or mounted on a gimbal. This review was carried out with an auto-aperture version of the lens.
Angled view of the Laowa 7.5mm f/2 MFT lens, standard black version. (Source: Venus Optics.)
Interestingly, this Laowa lens doesn’t provide the widest angle of view for the M4/3 format; that honour is shared by the Olympus M.Zuiko Digital ED 7-14mm f/2.8 PRO and Panasonic’s Lumix G 7-15mm f/4.0 ASPH. zoom lenses at their widest setting. However, both those lenses are somewhat heavier and more expensive although they benefit from auto focusing and exposure coupling.
The Laowa lens only offers aperture coupling in one version and that one has the highest price and is only available in black. The standard and lightweight versions are available in black or silver and both include an aperture adjustment ring, which is absent from the auto-aperture version.
This illustration shows the physical differences between the standard version of the lens (left), which has an aperture ring and the auto-aperture version (right) which doesn’t. (Source: Venus Optics.)
The optical design of all three versions of this lens, shown below, contains 13 elements in nine groups and includes two glass aspherical elements, three ED (Extra-low Dispersion) elements plus a water-repelling Frog Eye Coating that stops rain and spray droplets from settling on the surface of the lens. It can also repel dust particles.
The optical design of the Laowa 7.5mm f/2 MFT lens, showing the positions of the exotic elements. (Source: Venus Optics.)
The lens is supplied in a handsome, heavyweight cardboard box with a magnetic closure. It comes with front and end caps plus a shallow petal-shaped lens hood, which was attached when we unpacked the lens.
Who’s it For?
Different versions of this lens will appeal to different types of user and each has a different price tag. The table below provides a quick comparison of key features in the three versions.
|Manual version||Automatic aperture version|
|Angle of View||110°||110°|
|Lens Structure||13 elements in 9 groups||13 elements in 9 groups|
|Min. Focusing Distance||12cm||12cm|
|Dimensions||~50 x 55mm||~53 x 48mm|
|Weight||170g (Standard Version)
150g (Lightweight Version)
|RRP||US$499/AU$929 (Standard version)
US$519/AU$955 (Lightweight version)
|US$549 / AU$979|
Encompassing a field of view equivalent to a 15mm lens on a camera with a 35mm sized sensor, this lens will appeal to landscape and architectural photographers who need a wide angle lens with minimal distortion. The wide angle of view and fast maximum aperture will be useful for astro-photography. Its light weight and compact size make it ideal for bushwalkers and others who shoot stills and video outdoors.
The standard and auto-aperture versions are light enough to make the lens easy to carry but if it’s to be carried by a drone, one of the lightweight versions would be preferable. Lightweight versions are also more suitable for gimbal usage.
Those who plan to mount the lens on drones and/or gimbals should note that, like the standard version, the lightweight lens has no electronics contacts that link it with the camera. Aperture settings must be adjusted via the aperture ring.
This means no control over aperture and focus while the camera is out of the photographer’s hands. It also means EXIF metadata can’t be recorded in the resulting image metadata.
In the auto-aperture version a line of 11 gold-plated contacts encircles part of the lens mount, enabling the camera to record data such as aperture, shutter speed, ISO, exposure compensation, metering mode, flash mode and date created in the image metadata. Exposure mode and white balance are also recorded.
Photographers interested in sunstars should note the differences in the number of aperture blades between the auto aperture version and the fully-manual lenses. There are only five blades in the former, which means ten-pointed sunstars, whereas seven blades in the two manual lenses will produce 14-pointed stars.
Build and Ergonomics
Although some photographers are reluctant to choose manual-focus lenses, in practice using this lens is quite easy. For subjects further than about two metres from the camera you can simply set the focus to between about 1.5 metres and infinity and the aperture to f/5.6 or smaller and everything should appear sharp.
For closer subjects, most users will find it relatively easy to ‘guesstimate’ the subject distance and then refine focus with magnified live view mode. We found most subjects – including close-ups – are best captured at medium aperture settings.
The build quality of the review lens was very good, with a metal barrel and chromed metal mounting plate that fitted snugly to our Olympus E-M1 II camera body. The supplied lens hood is small and quite shallow and we found it impossible to remove without risking damage so we opted to leave it mounted. This made the lens cap a bit more difficult to fit – but not impossible.
The front element is roughly 20 mm in diameter and bulges out a little. It is surrounded by a ring of fine ribbing, which carries the label ‘C-Dreamer 7.5mm F2.0 Ø46 mm NO 008562’ in white and ends at a raised thread for 36 mm filters. The lens is protected by the Frog Eye coating.
There is only one adjustable control on the automatic aperture version of the lens: the focusing ring, which is approximately 25 mm wide. It has a 15 mm wide band of ribbing around its leading edge, while its trailing edge is stamped with distance settings – in red for Imperial measurements and white for metric – from the closest focus at 0.12 metres to infinity. These settings line up against the depth-of-field scale on the fixed section of the lens barrel between the focusing ring and the lens mount.
The manual aperture rings on the standard and lightweight versions of the lens make them a little longer than the automatic aperture version and the standard version is 20 grams heavier. Otherwise they’re effectively identical, although the automatic aperture version of the lens weighs the same as the lightweight version.
The lens barrel ends in a solid metal mounting plate, which lacks an index mark to show the orientation for mounting the lens. And since there’s no rubber gasket to indicate weatherproof sealing, users must rely on the snug fit of the lens and use of internal focusing to minimise the chance of dust and moisture getting in.
We found the automatic aperture control on the review lens to be very effective at matching shutter speeds to the light levels measured by the camera’s metering system and can recommend this version to most potential purchasers. With fully manual lenses (which are slightly cheaper), the photographer would be required to evaluate exposure levels and set the camera accordingly, which could be quite challenging in some situations.
Imatest testing confirmed expectations that resolution across the field of view of the review lens would be quite variable. This is not unusual for an ultra-wide-angle lens where designers have concentrated on keeping distortion as low as possible.
Centre-of-field performance was well above expectations for the resolution of the camera’s 20.2-megapixel sensor, even with JPEG files. ORF.RAW files converted into 16-bit TIFF format with Adobe Camera Raw produced resolution that was too high to measure with the software; hence our relatively high rating for Image Quality.
Measurements made at roughly half way out to the periphery fell a little short of expectations but could be classed as reasonably good. Those made between 70% and 75% out from the centre were somewhat lower, which was evident test shots taken with wider aperture settings. The results of our test are shown in the graph below.
Lateral chromatic aberration was well up in the ‘moderate’ band, shown by the green line in the graph of our test results below. Without in-camera corrections, similar results were obtained for JPEG and ORF.RAW files. The issue was confirmed in test shots so we recommend shooting raw files when this lens is used as it’s relatively easy to correct most of the problem when converting files into editable formats.
In camera corrections normally tend to address both rectilinear distortion and vignetting in JPEGs so all assessments must be made on raw files. But with the review lens, this information is not passed to the camera so both JPEGs and raw files showed these aberrations to the same degree.
Barrel distortion was obvious in our dedicated tests, even when the lens was absolutely square-on to the subject. But it was not nearly as bad as we would have expected for such a wide angle-of-view, a good result for a lens of this type.
Vignetting is also common on ultra-wide angle lenses and the review lens was quite heavily affected. It was clearly visible at f/2 but had largely vanished by f/5.6.
Backlighting presented another challenge for the review lens, which was prone to flare when a strong light source was within the image frame. Ghosting and flare artefacts were an issue at such times, although when the light source was partly occluded, the review lens could produce attractive 10-pointed sunstars at apertures smaller than f/16. (Examples are shown in the Samples section below.)
Nobody buys an ultra-wide angle lens for its bokeh qualities so it’s no surprise to find they’re not great in this lens. But they’re certainly not unpleasant and no worse than other ultra-wide angle lenses produce.
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Picture angle: 110 degrees
Minimum aperture: f/22
Lens construction: 13 elements in 9 groups (including 2 glass aspherical, three ED elements and Frog Eye Coating)
Lens mounts: Micro Four Thirds
Diaphragm Blades: 5 (circular aperture)
Weather resistance: Not specified
Focus drive: Manual focus
Minimum focus: 12 cm
Maximum magnification: 0.11:1
Filter size: 46 mm
Dimensions (Diameter x L): Approx. 53 x 48 mm
Weight: 150 grams
Standard Accessories: Front and end caps, petal-shaped lens hood
Distributor: Venus Optics
Based upon JPEG images captured with the Olympus OM-D E-M1 Mark II camera.
Based on ORF.RAW images recorded simultaneously and converted into 16-bit TIFF format with Adobe Camera Raw.
Recorded with the review lens on the Olympus OM-D E-M1 Mark II camera body.
Vignetting at f/2.
Vignetting at f/5.6.
Close-up; ISO 200, 1/20 second at f/8.
ISO 200, 1/320 second at f/10.
ISO 200, 1/125second at f/16.
Backlit subject with sun obscured; ISO 200, 1/25 second at f/20.
Flare artefacts with strong side/front lighting; ISO 200, 1 second at f/20.
ISO 200, 1/1000 second at f/5.6.
Crop from the above image at 100% magnification showing edge softening and coloured fringing.
ISO 200, 1/80 second at f/8.
Crop from the above image at 100% magnification showing edge softening and coloured fringing.
Sunstars at f/22, ISO 400, 1/20 second.
Crop from the above image at 100% magnification.
Perspective distortion; ISO 200, 1/25 second at f/11.
ISO 200, 1/100 second at f/16.
ISO 200, 1/1600 second at f/5.
ISO 400, 1/100 second at f/11.
ISO 400, 1/20 second at f/13.
RRP: AU$979; US$549 (for auto-aperture version, as reviewed)
- Build: 8.8
- Handling: 8.9
- Image quality: 8.9
- Versatility: 8.5