Metabones® Introduces Canon EF to EOS R (RF mount) Speed Booster®

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Vancouver, Canada, November 22, 2019 - The award-winning Metabones® Speed Booster® with optics by Caldwell Photographic Inc., which makes lenses faster, wider and sharper (note 1), gets a rather unexpected addition to its line-up - Metabones EF-RF Speed Booster ULTRA 0.71x - to adapt Canon EF mount full-frame lenses to the new Canon RF mount. Filmmakers are now able to mitigate most of the 4k video crop factor of EOS R (1.75x) and EOS RP (1.63x) and reduce it to 1.24x and 1.15x respectively. The field of view is now much closer to still photo mode. This new Speed Booster is not intended for still photography, but will work if the camera is configured to APS-C mode.

Videography with today's technology typically involves difficult engineering choices. As the resolution of the image sensor increases, there is not enough bandwidth to convert, move and process all the data from the sensor at video frame rates. The camera designers are then faced with a trilemma: 1, reducing the resolution of the sensor will both increase low light sensitivity and solve the video bandwidth problem but at the expense of still photo resolving power, 2, the brute-force approach of increasing A/D conversion, readout and processing speed will increase noise, shorten battery life and risk heat dissipation issues, and 3, pixel binning and 1:1 readout from the center portion of the sensor are the most common design choices, but the unused pixels are just throwing useful light away, increasing noise. None of these 3 solutions are ideal and this is the reason why many digital cameras on the market have a crop factor when shooting 4K video.


Speed Booster offers a viable solution to this trilemma. By 'condensing' the full-frame coverage of the lens to a smaller APS-C image circle, we get great low-light capability in 4K video mode on cameras which adopt the center cropping strategy. Footage has the appearance of the full-frame sensor size. Wideangle lenses remain wide angle.


EF-RF Speed Booster ULTRA 0.71x has a multi-function control wheel that can be programmed to control ISO, shutter speed or aperture. In addition, the wheel can be pushed in like a button. That in turn can be programmed to be a depth-of-field preview or numerous other functions. EF-RF Speed Booster ULTRA 0.71x has a 'chip' emulation function for fully mechanical manual lenses. The user may preset lens metadata using the Metabones App. To make sure this 'chip' emulation function does not get in the way when not required, it is only activated after pushing the control wheel inward. Since both the lens and the camera speak the same protocol most features are supported with the exception of lens aberration correction, which is automatically turned off. The autofocus speed of the lens is adjusted and optimized for the change in focal length and aperture to ensure the best performance. This is especially important for dual-pixel autofocus (DPAF) in video mode on EOS R. Although EOS RP supports both 4K video and DPAF they cannot be combined. For this reason, we recommend EOS R over EOS RP to our patrons who use autofocus.


Speed Booster ULTRA


Speed Booster ULTRA uses an advanced 5-element/4-group optical design by Caldwell Photographic Inc., incorporating ultra-high index tantalum-based optical glass to achieve extraordinary optical performance with improved corner sharpness, distortion and reduced vignetting. Speed Booster ULTRA has a magnification of 0.71x, effectively reducing the crop factor of 4k video on EOS R from 1.75x to 1.24x and on EOS RP from 1.63x to 1.15x. The Speed Booster ULTRA design makes very effective use of exotic materials at the furthest limit of glassmaking technology, and as a result is well corrected for use with virtually all full-frame SLR lenses regardless of exit pupil distance. Thus, the Speed Booster ULTRA performs extremely well with professional-grade f/2.8 zoom lenses such as the 24-70mm f/2.8 and 70-200mm f/2.8 zooms by Canon to produce 17-50mm f/2.0 and 50-142mm f/2.0 high-speed zooms, respectively. Similarly, high-speed fixed focal length lenses such as a 50mm f/1.2 will be transformed into a 35.5mm f/0.9 lens with excellent contrast and resolution from the center all the way to the edges of the image.



Metabones® EF-RF Speed Booster® ULTRA 0.71x is available right now for USD479 plus applicable taxes, duties and shipping, from Metabones' web store and its worldwide network of resellers.

Note 1: compared to the same lens on the same camera with an ordinary lens mount adapter without optics.



Product name (Model Code):

Canon EF Lens to EOS R (RF Mount) T Speed Booster® ULTRA 0.71x (MB_SPEF-EFR-BT1)

Product page:

Dimension: 28.1 x 73.0 x 77.2mm

Weight: 198g

Retail Price: USD 479.00

Color: Black Satin exterior; Black Matte interior



About Metabones

Metabones®, together with its allied partners Caldwell Photographic and WB Design, is the pioneer and leader of two key technologies which have catalyzed the transition from mirror to mirrorless. Speed Booster® (winner of the 2013 TIPA Best Photo Accessory Award) makes lenses brighter, wider and sharper, and Smart Adapter™ breaks the lens mount compatibility barrier by electronically integrating interchangeable single-lens reflex (SLR) lenses and mirrorless cameras. Metabones® offers a comprehensive range of adapters covering most popular lens mounts, as well as some rare and exotic ones. "Always at the forefront of innovation without ever setting aside practicality as a professional tool" perhaps best epitomizes Metabones' philosophy.

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