Sometimes we want to increase a lens’ image circle so it can be adapted to fit more cameras. This is where optical lens adapters come in. One great example is adapting a 2⁄3-inch B4-mount lens to a PL-mount camera. The HDx35 adapter from IB/E both adapts the mount and increases the image circle of the lens. It spreads the 11mm image circle of the 2⁄3-inch lens out to cover Super 35. Doing this means you lose over 2 stops of light; you can’t spread light out without losing something along the way, but you gain the ability to use these lenses on large-sensor cameras.
The IB/E adapters work with their Universal Mount System (UMS), which allows PL-mount adapters to be easily converted to EF-, E-, F-mount and more. They also make a 2⁄3-inch adapter, the HDx1.4, which adapts 2⁄3-inch B4 lenses to cover a Super 16 image area, as well as PLx2 and PLx1.4 adapters, which are image magnifiers that work on a variety of lenses.
"A common assumption is that a PL lens can be adapted to EF-mount… However, the physical designs of most PL lenses prevent them from being adapted…"
Finally, there are optical adapters that do essentially the opposite of what the HDx adapters do. These adapters shrink an image circle from a lens to preserve field of view. We generally call these "speed boosters" because they focus the light output of a lens in a smaller area—arguably making the lens faster. A popular example of this is the EF to E-mount Speed Booster from Metabones.
BACK IN FOCUS
Although this whole topic may seem a bit confusing, and full of caveats, we’re seeing a trend in the industry that makes the whole process easier. Sony, ARRI, RED, Canon and other camera manufacturers are offering interchangeable-mount systems for their cameras, and both Sony and ARRI are offering their own native 2⁄3-inch adapters, as well. This, along with the wide variety of adapters available today, means we can keep our older lenses working for years to come.
Andy Shipsides is the Director of Education at AbelCine. AbelCine’s training department offers practical classes for serious image-makers of all levels on professional production technology encompassing cameras, optics, audio, lighting, workflows and post solutions. Classes are available in person at their New York, Chicago and Burbank locations, as well as online. Visit training.abelcine.com for more information.