Los Angeles, CA, USA, Aug 16, 2019: Caldwell Photographic Inc. and Metabones® are pleased to announce a new Speed Booster® Ultra 0.71x, exclusively designed for the exciting new Fuji GFX medium format camera. The initial version is specifically optimized for use with the famous Hasselblad V series lenses. This new Speed Booster uses an advanced 6-element design to achieve excellent optical performance at apertures up to f/1.4 when paired with the Hasselblad 110mm f/2 lens.
Although the Fuji GFX uses an extremely large sensor, it is nevertheless significantly smaller than the 6x6 cm film format. The new Speed Booster Ultra 0.71x is an ideal match for 6x6 Hasselblad V lenses since they can now be fully utilized as they were originally designed when mounted to the Fuji GFX. Unlike 35mm format lenses used on the Fuji GFX via glassless adapters, Hasselblad V lenses adapted to the GFX via the Speed Booster Ultra are completely free of disturbing vignetting and other corner issues.
In addition to increasing the field of view and lens speed, the new Speed Booster Ultra achieves superb performance by being carefully matched to the unique optical characteristics of the Hasselblad V lenses. All of the Hasselblad V lenses were analyzed for exit pupil size and location, and this was fully taken into account in the new Speed Booster Ultra for the Fuji GFX. This approach dictated the use of extremely large lens elements throughout in order to avoid vignetting and maintain high quality imagery into the corners, but the results speak for themselves.
Like all Metabones Speed Boosters, the Hasselblad-V to GFX Speed Booster Ultra is optimized to fully account for the camera’s filter stack located near the sensor surface. This is especially critical when using high-speed optics like the 110mm f/2, which becomes a high-performance 78mm f/1.4.
In addition to superb optical performance, the Hasselblad-V to GFX Speed Booster Ultra is equipped with an extremely robust cine-style positive locking mechanism to ensure that no play occurs during focusing. This is especially important when using Hasselblad V lenses for cine work because even though they provide a very smooth focus movement, they tend to require more torque than lesser lenses. The new Ultra also includes a very sturdy 360-degree rotation collar and extra length Arca Swiss style tripod mounting plate.
(1) MTF data is a full diffraction-based calculation that assumes the Speed Booster is attached to a perfect master lens having an exit pupil distance of 120mm. Note that the MTF calculations do not take into account vignetting inherent in the master lens, so actual results at large apertures are likely to be better than the calculations indicate.
(2) Illumination data assumes a perfect master lens with an exit pupil distance of 120mm and zero vignetting. The slight falloff shown at f/4 is due to cos4 effects alone, as the mechanical vignetting is zero. Actual results will depend on the exit pupil distance and vignetting characteristics of the master lens used.
(3) Distortion data assumes a perfect master lens with an exit pupil distance of 120mm and zero distortion. Actual results will depend on distortion characteristics of the master lens used.