Tim Dashwood
January 14th, 2013, 08:03 PM
Metabones has released the first in its series of "Speed Booster" adapters. It uses an optical reduction lens that widens the angle of view by 0.71x, improves MTF, and increases light transmittance by 1-stop (twice as bright.) Canon EF is the first version available and Leica R, ALPA, Contarex, Contax C/Y and Nikon F (with aperture control for G lenses) versions will follow soon.
Metabones - Metabones and Caldwell Photographic Introduce Speed Booster (http://www.metabones.com/info/105-info/154-speed-booster)
So how does it increase the speed of the lens? It’s a basic optical imaging law known as the “Lagrange Invariant” or simply the optical invariant. Reducing the resultant image size will increase the overall brightness by the same factor (minus a tiny loss due to diffraction.) However, the depth of field will remain the same as the actual focal length and aperture used on the taking lens (as shown in the test shots above.)
This is good news for those of us who shoot high-speed with our FS700 cameras. An extra stop comes in very handy when shooting at 240fps!
It is an old concept that has been done a few times, first by Angeneuix/Zeiss and most recently in JVC’s HZ-CA13U 16mm to 1/3″ adapter. Some technical info and test results are in this review I wrote a few years ago. http://www.dashwood3d.com/downloads/HZ-CA13U.pdf
I am surprised by the considerably low price (compared to $4000 of the JVC adapter) and the fact that it does not invert the image. I’m looking forward to testing out the Nikon version on my FS700 when it is released.
Metabones - Metabones and Caldwell Photographic Introduce Speed Booster (http://www.metabones.com/info/105-info/154-speed-booster)
So how does it increase the speed of the lens? It’s a basic optical imaging law known as the “Lagrange Invariant” or simply the optical invariant. Reducing the resultant image size will increase the overall brightness by the same factor (minus a tiny loss due to diffraction.) However, the depth of field will remain the same as the actual focal length and aperture used on the taking lens (as shown in the test shots above.)
This is good news for those of us who shoot high-speed with our FS700 cameras. An extra stop comes in very handy when shooting at 240fps!
It is an old concept that has been done a few times, first by Angeneuix/Zeiss and most recently in JVC’s HZ-CA13U 16mm to 1/3″ adapter. Some technical info and test results are in this review I wrote a few years ago. http://www.dashwood3d.com/downloads/HZ-CA13U.pdf
I am surprised by the considerably low price (compared to $4000 of the JVC adapter) and the fact that it does not invert the image. I’m looking forward to testing out the Nikon version on my FS700 when it is released.