Sep 24, 2021
4 mins read
With the release of the Sony A1, a camera company pushed the boundaries of sync speed for the first time since I've been a photographer. When I started photography ISO 400 looked like a bag of processed dog food, and now I can get useable images when shooting 128x (7 stops / ISO 51,200) higher. So how is it that it took 15 years to push the mechanical sync limit a measly stop?
This same camera is the first to sync it's electronic shutter with flash. Previously, cameras couldn't do this because the sensor readout time was far longer than the duration of a flash pulse. So, since electronic shutters have been present in cameras, companies avoid this issue entirely by having flash simply not fire when using the electronic shutter. But the A1 not only syncs with it's electronic shutter, it syncs at any shutter speed, albeit not harnessing the max potential of the flash.
And now there's rumblings of a Sony A9III that has no mechanical shutter. It will offer only an electronic shutter, and sync up to 1/500s, and likely - similar to the A1, kind of work at any shutter speed.
Nikon, Canon, and Fuji will all be forced to compete with this new standard that Sony is developing. It will get faster, it will drip down to cheaper camera bodies, and pretty soon we'll even see a global shutter that completely remove any issue that is currently caused by a non-instant electronic shutter (like banding / rolling shutter).
There's one issue though : Flash durations.
The flash duration is the time it takes a flash pulse to dissipate from it's peak brightness. The most common figure is a "T.1" flash duration, with the .1 meaning the time it takes from peak brightness to 10% (.1) of it's peak brightness. Some brands (I'm looking at you Profoto) market a T.5 figure to inflate their numbers for marketing, despite it not being a very helpful figure for photographers. A T.1 flash duration is great for knowing the action-freezing potential of your flash. You can imagine, when a flash dissipates to 1/10th (over 3 stops) of it's peak brightness, it's almost not affecting your exposure anymore. So a super short flash t.1 flash duration like 1/10,000s can reliable freeze most fast-moving subjects.
Here's the issue though. For years flash companies have maximized their product's peak brightness by extending the flash duration at full power. And their limiting number? You guessed it, the sync speed of flash, or 1/250s. Some companies (I'm looking at you Godox) even exceed 1/250s, with t.1 flash durations at 1/1 power closer to 1/200s.
Well, if our camera's sync speed is 1/500s and our flash dissipates 90% of it's light in 1/200s, that would mean a large portion of our flash isn't even being captured by our camera sensor. This is true of a mechanical shutter now. This will be true of an electronic shutter that is capable of syncing with flash. And this will be true with a global shutter than can trigger standard sync at any shutter speed since it's no longer limited by a mechanical curtain window.
Now imagine a world where some cameras shutter can sync at 1/2000s, others at 1/1000, some 1/500, and still dSLR bodies floating around at 1/160th. The rules of lighting would get ridiculously anecdotal based on the lighting, and camera used.
For instance, if you shoot with full power on an AD1200 Pro with a Sony A1 at 1/500 - half of the flash pulse isn't captured, meaning your camera captures 1 stop less light than it would at 1/250. However, if you drop the flash power down to 1/2, the FDA shortens, and now the entire pulse squeezes into the 1/500s shutter speed. So 1/2 power and 1/1 power would yield the same brightness if the Sony A1 is at 1/500s. The age old rule of shutter speed only affecting the ambient light (when below max sync speed) is no longer true.
Right now, this is a relatively simple caveat to explain to someone who is confused by their experience, but just imagine when this expands to more camera bodies, and higher sync speeds.
Lighting will be forced to adapt.
I foresee 3 possibilities for lighting to adapt to this change.
1) Nothing happens. You now lose light as you increase your shutter speed even if you're below sync speed. Figure it out.
2) The strobe race changes from brightness over size, to how short they can make the full power Flash duration. This would be interesting - because there are older technologies like variable voltage flashes that actually have shorter flash durations at their higher outputs. This could make a comeback, or at least provide a springboard for new development. But regardless, I would love to see a modern flash that offers an t.1 FDA of 1/2000s at full power.
3) Controllable FDA. I'm great at seeing problems, but I'm not great at resolving them. I have no idea if this is possible but maybe you'll be able to manually control the FDA along with the output in the future. Pray for my lighting tests if this is the case.
My biggest concern with this is lighting companies not taking this seriously - and camera companies using it as an opportunity to make you buy their lighting solutions. Imagine flash can only be triggered internally, using proprietary solutions, something Canon previously flirted with.
So yeah, these are things I think about.