- Increase maximum aperture by 1 stop.
- Increase MTF.
- Makes lens 0.71x wider.
- Felt material flocked inside to reduce internal reflection.
- 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) lenses.
- 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.
- 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 big 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".