Metabones Canon EF to E Mount T Speed Booster ULTRA 0.71x - Black Matte

The Metabones Canon EF to E Mount T Speed Booster ULTRA 0.71x - Black Matte features an advanced 5-element/4-group optical design incorporating ultra-high index, tantalum-based optical glass to achieve extraordinary optical performance with improved corner sharpness, distortion and reduced vignetting.

The Speed Booster ULTRA has a magnification of 0.71x, effectively reducing the crop factor of mirrorless cameras with DX-sized sensors (such as Sony E-mount and Fuji X-mount cameras) from 1.5x to 1.07x.  However, the new ULTRA design makes very effective use of exotic materials at the furthest limit of glassmaking technology, and is well corrected for use with virtually all full frame SLR lenses regardless of exit pupil distance.

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 and Nikon, 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.

Features:

• Advanced 5-element/4-group optical design incorporating ultra-high index tantalum-based optical glass by Caldwell Photographic in the USA (patent pending)
• AF-C tracking during high speed drive at up to 10fps on Sony A9
• If both your lens supports optical image stabilization (OIS) and your camera supports sensor-shift, in-body image stabilization (IBIS), the choice is yours on which one to use, or have both of them work together
• Smooth iris support with the latest Canon (2009+), Tamron (SP series 2013+) and Sigma (2016+) lenses
• Custom function button (Focus Hold button) assignable to more than 50 functions, such as Aperture Preview and Eye-AF, on A9, A7 series, A6500 and A6300
• Cinema EOS lens (CN-E) support, including power zoom, AF and auto iris
• Detachable tripod foot, compatible with Arca Swiss, Markins and Photo Clam ball heads

Optical / Mechanical Specifications:

• Increase maximum aperture by 1 stop
• Increase MTF
• Makes lens 0.71x wider
• Felt material flocked inside to reduce internal reflection
• Full-frame lens required (EF-S/DX/DC/Di II lenses are NOT supported)
• Speed Booster ULTRA is designed to cover an APS-C image circle, which is not large enough to cover a full-size 36mm x 24mm sensor
• On a full frame camera body (A7 series, NEX-VG900) the camera needs to have "APS-C/Super 35mm" set to either "Auto" or "On"

Electronic Specifications:

• Fast contrast-detection AF on all E-mount cameras (except AF-S/DMF with Sony A9)
• Pure phase-detection autofocus support on A9, A7RII, A7II, A6500 and A6300 (the fastest)
• Supports 5-axis in-body image stabilization of A7II, A7RII and A7SII (distance information from lens required; 3-axis IBIS if lens does not transmit distance information)
• Powered by camera body; no external power source required
• Efficient switched-mode power supply
• Supports image stabilization (IS) lens
• Supports electronic manual focusing (e.g. EF 85/1.2L II and discontinued EF 50/1.0L)
• EXIF support (focal length, aperture, lens name)
• Distance and zoom display on VG and FS series camcorders, A9, A7 series, A6500 and A6300 (lens with distance information support required)
• Auto magnify (lens with distance information support required)
• Auto "APS-C Size Capture" on full-frame cameras

Autofocus Specifications:

• AF-C is supported on A9, A7RII, A7II, A6500 and A6300 only, and only in Green mode
• Continuous video AF is functional in Advanced mode, but performance may be unsatisfactory
• On Sony A9, only phase-detection autofocus is supported; contrast-detection autofocus does not work (see firmware release notes for details)
• AF may not work if the maximum aperture of the lens plus any EF Extender or other teleconverter attached is smaller than f/8 before boost or smaller than f/5.6 after boost
• The first two autofocus attempts are used to calibrate the lens and as a result may not lock successfully on the target. Half-press the shutter release button again and autofocus will lock successfully
• Autofocus may have difficultly locking onto subjects which are very close to the nearest focusing distance of the lens
• Autofocus accuracy depends heavily on the design and working condition of the lens; lenses with hidden problems which may not be apparent on Canon DSLRs will lead to inaccurate and unreliable autofocus on Sony (typical problems of this kind include an unsmooth/erratic autofocus mechanism, e.g. getting stuck intermittently at a certain focusing distance, a faulty/worn-out distance encoder, or other faulty/worn internal sensors)

Other Specifications:

• No support for lens corrections such as peripheral shading, CA and distortion
• Use of Canon Cinema lenses such as CN-E 18-80mm T4.4 for still photography is not supported (functional, but slower than lenses designed for still photography)
• Some EF-mount lenses may make audible noises during iris changes and autofocus, wich may be picked up by the built-in microphone of the camera during video recording; use of an external microphone is advised (some of the recently-introduced Canon-brand lenses are very quiet, however)
• Early Tamron VC lenses such as the AF 28-300/3.5-6.3 XR Di VC LD Aspherical [IF] Macro (model A20), AF 18-270/3.5-6.3 Di II VC LD Aspherical [IF] MACRO (model B003), SP AF 17-50mm F/2.8 XR Di II VC LD Aspherical [IF] (model B005) may not be able to freely switch between OIS and IBIS because they may not report IS activity status; later Tamron VC lenses equipped with USD or PZD focus motors are compatible.
• Some aftermarket battery grips may cause the aperture to change erraneously; this is a bug inherent in the aftermarket battery grip, NOT the Metabones Speed Booster.