FIFTY
piece of metal.
Most barrels are two shells and a seam. This one starts as a single billet of 6061-T6 and comes out of the machine as one part, which is why the wall thickness never drops below 1.8mm and why the whole thing rings rather than rattles.
The consequence is weight — 684 grams of it. That is the trade, stated plainly: a lens that holds its alignment for twenty years is not going to be a light one.
- 01Front element72mm · ground fluorite
- 02Focus ring165° throw · knurled
- 03Aperture11 blades · f/1.2–f/16
- 04Barrel6061-T6 aluminium
- 05Index ringEngraved · lume-filled
- 06Rear elementAspherical · nano-coated
- 07MountStainless bayonet
- 08Contacts11-pin · gold
Keep scrolling — the assembly comes apart along its optical axis, front element first.
Eleven blades, curved rather than straight. Straight blades are cheaper and give you a star at every point of light; curved ones hold the opening round all the way down, so what was a highlight stays a highlight.
- Nano coating
Sixteen air-to-glass surfaces, each one a chance for light to bounce back at you. The coating is what keeps a backlit frame from washing out.
- Damped helicoid
Brass on brass, packed with a grease that holds its viscosity from a cold morning to a hot lamp. The resistance you feel is the same in either.
- Weather sealing
A gasket at the mount and again at every moving ring. Rated IP52 — rain and dust, not the bottom of a river.
- Balance point
The mass sits back toward the mount, so the lens hangs off the body instead of tipping it forward. You notice this after an hour, not a minute.
Silver
Bead-blasted alloy
The same machine work under every one. Anodising is thinner and harder; the bare metals are softer and will take a mark — which some people want and some people very much do not.
- Focal length
- 50mm
- Maximum aperture
- f/1.2
- Minimum aperture
- f/16
- Optical formula
- 9 elements / 7 groups
- Aperture blades
- 11, curved
- Closest focus
- 0.40m
- Filter thread
- 72mm
- Weight
- 684g
- Mount
- Stainless bayonet
- Weather sealing
- IP52
A lens is just a way of deciding
what to leave out.