UPDATE: Strobist was archived in 2021.
Here is what I am up to now.


Leaf Shutter + ND + Flash: A Fuji X100s Daylight Primer

Right about now I feel like Alice in Wonderland, holding the "drink me" cup. Having a leaf shutter, a built-in 3-stop neutral density filter and a real chip in a compact camera is opening up a whole new world of possibilities.

But with these possibilities come some quirks, some compromises and a few technical things to be mindful of. What you need to know about leaf-shutter compacts and daylight flash, below.


Looking at my Google calendar, I have half a dozen shoots scheduled over the next two weeks. And for every one of them, I am now trying to figure out ways to explore the sunlight-killing sync capabilities of my X100s.

What I am finding: there are real limitations involved. But once you get a grasp of the quirks, there is still plenty of room to do things you have never been able to do before.

This post will be part example, part white paper and part hacker guide. And my hope is that it'll be a useful reference for people going forward.

Wide-Open Flash

The first thing you have to realize with a leaf-shutter compact is that even the tiny little built-in flash actually becomes surprisingly useful. Is it powerful? Nope, not by a long shot. But cranking the shutter and shooting wide open gets you a lot of bang for your lumen buck. Also, being able to shoot flash wide open in daylight gives your photos a look that almost (ironically) evokes the soft backgrounds of a much bigger chip.

The photo at top is a quick snapshot of Mandy, one of our Cuban hosts in Havana last month. It's shot at 1/300th of a second (no huge jump there) at f/2 at ISO 100.

I have the ISO as low as it can go, with the 3-stop ND filter engaged, to kill as much ambient as possible. I am set to wide open (to soften the background) and letting the camera choose a shutter speed.

From that point I am letting the on-board flash drive, set to TTL -⅔ stop. (McNally is in Lagos, Nigeria. So I can safely print this.)

I am not sure if that -⅔ is from full TTL or from an already fill-balanced TTL. Fuji really doesn't parse that too well in the manual. But a zoom-in to the collar area reveals just how much that little flash is doing:

So the sun is my key, the flash is my fill and I am shooting wide-open on a sunny afternoon. It's just a quick snapshot, but the photo has a cool feel due to the wide-open depth of field. And that DoF is also helping my flash, in that it is far easier to balance at f/2 than at, say, f/16.

Except it Isn't Really f/2

But that's something you have to remember. As far as the flash is concerned, I am really at f/5.6 at ISO 100, because the ND filter is eating three stops of both ambient and flash. So the flash is having to work as if I am at f/5.6.

But I could easily knock down that background down an additional stop and a half or so by moving the shutter speed to 1/1000th of a sec and staying at f/2. The current flash power needs would not change at all.

!/1000th at f/2: The Sweet Spot

So, technically, the camera syncs at any speed. But (and this is a big but) the iris-like leaf shutter cannot go past 1/1000th when wide open. That's because the outer edges will get less exposure due to the physical properties of the shutter. So 1/1000th is as fast as you can go when wide open. If you want faster shutter speeds, you have to close down. And that's the real reason the ND is there to begin with, to offset that design limitation.

Yes, you can sync faster. But you have to close down. So there is no flash power advantage to speeding up your shutter, which would in normal circumstances buy you a more wide-open, flash-friendly aperture. Because ironically you have to close down your aperture too, due to the leaf shutter's limitation.

So while the camera syncs at any speed, your flash has the furthest possible "ambient-mix" reach when your shutter is at 1/1000th and the aperture is at f/2.

Your 240ws Speedlight

That's the leaf-shutter advantage, in a nutshell. But shooting wide open (for maximum flash advantage and nice backgrounds) your new sync ceiling is effectively 1/1000th. Or put differently, two stops up from 1/250th. Which effectively makes your flashes two stops more powerful when used with the X100s than when used outdoors with a 1/250th sync camera. (Cue the sobs of a thousand Canon users.)

So a 60ws speedlight becomes as useful as a 240ws monobloc in a typical outdoor portrait situation. A 640ws Einstein, for instance, is now more useful at 1000th than a 2000ws monobloc is at 1/250th on a normal camera. Which is doubly amazing when you consider how reasonable an Einstein is, when paired with a Vagabond Mini Lithium portable power source.

But Even Speedlights Can Reach Out in Sun

While in Cuba we did a very bootstrapped lit group portrait while out in the Viñales Valley, AKA tobacco country. The landscapes were amazing, and we thought this a much better venue than shooting the group in the hotel lobby.

I did not have flashes with me, but I scrounged two SB-800s from my friend Mark Heaps. We squeezed five minutes we didn't really have, in order to do a group shot before hitting the bus to another location.

Here is the entire setup—an X100s on a tripod, one on-camera SB for fill and a VAL'd, slaved SB-800 as a key. Pretty high tech, huh?

Photo ©Duncan Davidson

Don't look like much, as they say. But with a leaf shutter those SB's can in theory be almost almost as useful as Elinchrom Quadras. For the record, the fill was on ¼ power, the key was on 1/1 power. Exposure was at 1/500th, f/8. No ND is used here, because we want the backdrop to be in focus.

And a quickie, 19-person group shot in a full sun environment now looks like this:

And no, the posing is not very polished. Many were concentrating more on the hand-made cigars they were enjoying than on the group shot. And Erik, (3rd from right in the back) has not yet grasped the fact that if he cannot see the camera with both eyes, then it cannot see his whole face.

But holy crap, that camera is owning full daylight at twenty feet with just a couple SB's. The sun is directly overhead and darting in and out of the clouds. Look at the BTS shot again. Great choice for a group shot, huh?

And we still have some additional flash-to-subject room in that exposure, actually. This is why I am excited about actually taking some time to light outdoor images with this camera.

T.1 Times Matter

This really does not come into play with a normal, focal plane shutter. But in some cases, the actual length of the flash pulse, expressed as a t.1 time, will be your limiting factor.

Think of it this way: If your full-power flash pop actually takes 1/1000th of a second to fully happen, no system in the world will fully sync it at a 1/4000th of a second. It's like trying to squeeze a gallon of time into a quart-sized container. Not gonna happen.

So if you are running into weird limitations, do a little research and look into your particular flash's t.1 times at various power settings. That will probably point to a fix.

Fortunately, the "1/1000th at f/2 at ISO 100 with ND" sweet spot is pretty close to most flash's max t.1 time. But that exposure only gets me to a full-sun balance and soft background. What I want is to dominate full-sun and shoot at wide open. And for that, there is a cheap and easy fix.

Again with the ND?

Yes. So the camera has three stops of ND built-in. Which is awesome. And it's an actual, physical filter, too. And a good quality filter at that. But we can add more at the front of the lens. Don't need much, either, since we already have three stops. Two more stops as an aux-ND filter oughta do it:

This is a high-quality, 2-stop B+W ND filter. It's a good-quality filter, which is (fortunately) pretty cheap owing to its small, 49mm in size. So for an added ~$26, I can choose to use the two-stop filter, the built-in three-stop filter or combine them for a five-stop drop.

I don't have access to four-stops, but remember that is a global adjustment. So I can tweak that EV at my preferred f/2 aperture by adjusting the ISO by a stop.

Two Daylight-Dominating Kits

Needless to say, I am excited about what I can do with this camera in real daylight portrait situations. The limitation, as I see it, is the 35mm throw. I'll have to adjust to that field of view. And still, I'll likely have a second, traditional body with a 50 and a tele on set.

Having done a couple of quick tests, I can match sunlight in pretty close with a speedlight—even running it through an umbrella. So that's cool. A Fuji X100s and a speedlight kit is a great capability out of a super small kit. Adding a second speedlight allows me to gang them for one more stop of sunlight-killing power, or split them for a multitude of different looks.

Kick it up a notch with the X100s and a couple Einsteins, Photeks and a Vagabond battery, and I could dominate sun with a midday, 20-person group shot. Or, obviously, anything smaller than that. Like a single-person portrait, for instance.

Sorry to the uninterested for the windy, tech-heavy post. But long story short (and provided you are willing to learn the quirks and exposure limitations) this is an amazing capability out a small camera and a very portable piece of lighting kit.


New to Strobist? Start here | Or jump right to Lighting 101
Got a question? Hit me on Twitter: @Strobist
My current project: The Traveling Photograher's Manifesto