アダプター内にCaldwell社製の5枚4群レンズが内蔵され0.71倍ワイド化しF値を1段明るくできるSpeed BoosterULTRA搭載モデルです。マイクロフォーサーズでは通常2倍の画角（35mm換算）になるところが1.4倍の画角で利用できます。 光も同時に集光させる事で開放値も1段明るくなりMTF値、シャープネス、コントラストも向上する仕様となっています。
フェルト材料を採用したフロックコーティング処理により、アダプタ内に入った光の反射を抑えフレアを低減します。チルトシフトレンズ使用時などのパフォーマンス改善や逆光等の強い光の条件でさらに画質改善を行いました。電子接点によるオートフォーカス、EXIF情報、手ブレ補正等に対応します。
●テスト済みのカメラボディ
Blackmagic: Micro Cinema Camera, Pocket Cinema Camera
JVC: GY-LS300
Olympus: E-M1, E-M1 Mark II, E-M5, E-M5 Mark II, E-M10, PEN-F, E-P5, E-PL3
Panasonic: GX1, GX7, GX8, GX80/85, GH1, GH4, GH5, G2, G3, G5, G7, GM1, GF3, AF100
●Metabones（2017/12/13）によるレンズ動作検証リスト
Canon EF 8-15mm f/4L USM Fisheye*
Canon CN-E 18-80mm T4.4L IS KAS S* (requires external power to autofocus)
Canon EF 20-35mm f/3.5-4.5 USM
Canon EF 24-105mm f/4L IS USM
Canon EF 28-80mm f/3.5-5.6 II
Canon EF 35-80mm f/4-5.6
Canon EF 40mm f/2.8 STM*
Canon EF 50mm f/1.2L USM
Canon EF 50mm f/1.4 USM
Canon EF 50mm f/1.8 STM*
Canon EF 70-200mm f/2.8L IS II USM*
Canon EF 70-300mm f/4-5.6L IS USM*
Canon EF 85mm f/1.2L II USM
Canon EF 100mm f/2.8L IS Macro USM*
Canon EF 100-400mm f/4.5-5.6L IS USM
Canon EF 100-400mm f/4.5-5.6L IS II USM*
Canon EF Extender 1.4x III
Canon EF Extender 2x
Sigma 18-125mm f/3.8-5.6 DC HSM
Sigma 24-105mm f/4 Art
Tokina AT-X PRO 11-16mm f/2.8 DX II
※ユーザー検証によるレンズ動作検証リスト
Canon EF 70-200mm f/2.8L IS USM (Mark I)
Canon EF 85mm f/1.2L USM (Mark I)
Canon EF 200mm f/2.0L IS USM
Canon EF 300mm f/2.8L IS USM (Mark I)
Canon EF 400/2.8L IS USM (Mark I)
●Accurate only on newer cameras such as Panasonic G7, GX8 and GX80/85
Canon EF 70-200mm f/4L USM (non-IS)
Canon EF 135mm f/2L USM
Canon EF 200mm f/2.8L II USM
Canon EF 300mm f/4L IS USM
Canon EF 400mm f/5.6L USM
Sigma 18-35mm f/1.8 DC Art
Sigma 50-100mm f/1.8 DC HSM Art 016*
Tamron SP 15-30mm f/2.8 VC USD A012*
Tamron 18-270mm f/3.5-6.3 VC PZD B008
Tamron SP 45mm f/1.8 VC USD F013*
●Inaccurate
Canon EF 28-70mm f/3.5-4.5 II
Canon EF 50mm f/1.8 II
Canon EF 100mm f/2.8 Macro USM
Sigma 50mm f/1.4 EX HSM
Tamron 18-250mm f/3.5-6.3 Di II Macro A18
Tamron 18-270mm f/3.5-5.6 Di II VC B003
Tamron SP 24-70mm f/2.8 Di VC USD A007
Tamron 28-300mm f/3.5-6.3 XR Di Macro A06
Tamron SP 70-200mm f/2.8 Di VC USD A009*
Tokina AT-X PRO 11-16mm f/2.8 DX (I)
●Require external USB power supply owing to high current consumption; AF inaccurate
Tamron 28-300mm f/3.5-6.3 XR Di VC A20 (note 1)
Tamron 150-600/5-6.3 VC USD A011*
●Manual focus only
Contax N lenses modified by Conurus
Tamron SP 17-50mm f/2.8 VC B005
Zeiss ZE lenses
●Not supported
Focus confirmation “chips”
canon EF-S 18-135mm f/3.5-5.6 IS Nano USM
※補足注意事項
・* with smooth iris support
・ VC function of Tamron 28-300/3.5-6.3 XR Di VC model A20 may not operate, due to usually high current requirement.
●制約事項
・EF-S lenses require modification to fit or may remain incompatible even after modification (but third party DX lenses can be used without modification)
・Some EF-S and DX lenses may not have enough coverage of the entire image circle for stills after widening by 0.71x (but video will have enough coverage).
・No video AF for Olympus
・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.
・AFC (continuous AF) and AFF (flexible AF) modes are not supported, except on Olympus OM-D E-M1.
・Panasonic video AF may hunt more than a native lens or have unsatisfactory performance.
・Some Tamron lenses may have unsatisfactory AF accuracy.
・No support for Focus Stacking and Focus Bracketing on Olympus.
・On Olympus, other than E-M1, you may move the single AF point among any of the 81, but you may not multi-point AF. There is no restriction on E-M1 and Panasonic.
・Very early Olympus models (e.g. E-PL1) have no autofocus support.
・EF-mount lenses are not silent but may make audible click noises during autofocus operation and iris changes which may be picked up by the built-in microphone of the camera. An external microphone is recommended for video.
・Use of Canon Cinema lenses such as CN-E 18-80mm T4.4L IS KAS S for still photography is not supported.
・Iris changes are in 1/8 stop steps which may be noticeable in video recordings. Programmed exposure mode and shutter priority exposure mode should not be used for video. This limitation does not apply to Cinema EOS lenses which permit fine resolution iris control, such as CN-E 18-80mm T4.4 L IS KAS S.
・No support for in-camera correction such as peripheral shading, CA and distortion
・Designed to cover a 24mm image circle, JVC GY-LS300 needs to have VSM configured to 86% (4k) when using a true Super 35 lens such as Canon CN-E 18-80mm T4.4L IS KAS S. Higher VSM settings is possible with full-frame lenses, but will be operating outside of the design parameters of the ULTRA optical formula. Many APS-C/DX lenses do not have adequate coverage at 86% (4k) and on JVC with ULTRA the use of full-frame or true Super 35 lenses is advised.