Call Me Crazy: LS Lens Adapter Tube Concept

See this? This is an 80mm lens from my old Hasselblad film camera. It was built 50 years ago. The leaf shutter is built into the lens. It syncs at 1/500th of a second.

My current 80/2.8LS is a PhaseOne leaf-shutter lens. It syncs at 1/1600th. And it would be very possible—perhaps even simple—to manufacture an inexpensive tube to marry a PhaseOne LS lens to a Nikon or Canon DSLR.

Why, and how, inside.

Why Even Do This?

Without continuing to bang the "why" drum ad nauseum, suffice to say that for every stop you gain on your sync speed (1/500th vs. 1/250th, for instance) your flash effectively becomes twice as powerful vs. the ambient because of the corresponding change in your aperture.

And no, high-speed, focal-plane flash is not the same thing. It's mostly a gimmick that robs you of power very quickly. I am talking about true, high sync speed. Like shooting at 1/1 power on manual at, say, 1/1000th of a second.

The relative power that true high sync speed will give your flashes is almost magic.

But Nikon or Canon will never do this. They are all about the meat of the prosumer bell curve. Give 'em megapixels and pay Ashton Kutcher to hold it and look pretty. Let the sync speeds fall where they may.

How Could This Be Built?

First off, the lenses are already built. And because of the difference between the flange focal distances of 35mm vs medium format, you already have to use a thick adapter ring to mount a medium format lens on a 35mm body:

See that? That's a $75 third-party Mamiya/Phase to Nikon adapter tube. By design, it has to be almost an inch thick. That's plenty of room to house the fairly simple electronics it would take to marry PhaseOne's screaming sharp (Schneider glass) 80mm f/2.8 leaf shutter lens to a pro DSLR.

Yes, the lens is expensive. Two mortgage payments, figure. But the tube itself would be pretty reasonable. And the combo would be worth its weight in gold to, for instance, wedding and portrait shooters who light people outside. And this lens combo would travel with you to subsequent bodies—buy once, use for many, many years.

And you folks at PhaseOne, think of what this one piece of kit could do for you.

One, it would dramatically increase the market size (now pretty niche) for your LS lenses—especially the 80mm model. Two, when any of the LS-Adapter owners made the move to medium format, they would already have at least one Phase/Schneider lens. It would be hard to go Hassy. You'd grow your market again.

And three, the increased sales could very well change the economics of making the lenses themselves, driving the costs down to the benefit of all.

How Would the Tube Work?

It's kind of interesting, really. You are just matching the PhaseOne lens protocols to that of the Canon/Nikon bodies. (Two tube models would be needed.) Can't be that hard—3rd party manufacturers reverse engineer or license the protocols all the time.

Let's follow what would happen as you take a high-sync photo.

The Sync Chain

First off, the shutter that is contained in the lens is the new point of sync. Your flash would sync to a jack on the adapter tube itself. The tube would in turn hard-connect to the camera's sync jack or hot shoe.

The tube would have a shutter dial or button on it: 1/500th - 1/1000th - 1/1600th - and FP. When set to FP, the shutter and sync control would revert to the body and pass through if needed. When the tube was set to the higher speeds, the lens shutter would control the sync.

What Actually Happens When You Press the Button?

You'd want to set the camera itself on a slower shutter speed, as the lens will become the new, higher speed shutter. Let's call it 1/30th, but it does not really matter as the lens is blacked out during the time around that slower shutter speed.

Remembering that the body itself supplies power for the lens' focusing motor and timing signals for the process, follow the bouncing ball. Let's say you want to sync at 1/1000th. Your camera is on 1/30th. You press the shutter.

The first thing the lens normally senses is the signal that stops down the aperture. It will do so here, too, but this signal will also black out the leaf shutter.

Next, your body's focal plane shutter opens, but the lens' shutter is still closed.

The body then sends a sync signal (from the PC jack or hot shoe) when its shutter is fully open. This signal opens, and then syncs, the leaf shutter. After the required delay (depending on where you would need to set the host body shutter in our hypothetical example) the lens shutter would close and the body shutter also closes. Then the lens shutter would reopen, returning your visibility through the viewfinder.

Autofocus signal and power would pass through normally, just as with a third party lens.

A Guy Can Dream, Right?

So, PhaseOne, whaddya say? Will you build us this tube for us? Will you let us have the amazing sync speeds that make our flashes feel like they are on steroids?

Please say yes.

Besides, if you don't do it, some enterprising Chinese company (wink, wink) is going to build a stand-alone 80mm leaf-shutter lens for Nikon (and Canon, nudge, nudge) and maybe even a 35 or 50mm version (wink, nudge) and happily sell them to photogs all over the world at a thousand bucks a pop.


New to Strobist? Start here | Or jump right to Lighting 101
Connect w/Strobist readers via: Words | Photos
Got a question? Hit me on Twitter: @Strobist
Grab your passport: Strobist Destination Workshops