EB-1
Offline
• • • • • • •
Upload & Sell: Off
|
 p.1 #3 · Quantifying the 5-stop Global Shutter Advantage for Strobes | |
hiepphotog wrote:
I think the photography community is still dramatically underplaying the massive advantage a global shutter brings to strobe work.
In a studio setting where you are shooting below sync speed, it is absolutely true that your captured output simply scales with the flash's raw power rating. A big strobe is still a big strobe. However, the moment you step on location and push into high shutter speeds for shallow depth-of-field portraits, a global shutter like the one on the a9 III becomes an absolute godsend that completely changes the math on weight and power.
The Problem with the Old Workarounds We all know High-Speed Sync (HSS) robs you of massive amounts of power because the strobe has to pulse light as the mechanical shutter slit travels across the sensor. To avoid that, the traditional "ND workaround" involves using heavy ND filters to drop your shutter speed below sync speed. The flaw there is that an ND filter cuts ambient daylight and flash output equally.
The Pure Output Gain 📸 With a global shutter, you drop the ND filter entirely. You use ultra-fast shutter speeds to kill the ambient light, but because the entire sensor reads out instantly, you can capture the peak output of the flash without the penalty of HSS pulsing. In terms of pure output, a global shutter yields a full stop more light hitting the sensor than a standard ND filter workaround. Practically speaking, that is the equivalent of upgrading an AD200 to an AD400, but without any of the penalty in size and weight.
The Efficiency Multiplier 📉 The efficiency gains are even more staggering. Because flash duration gets significantly shorter as you lower the power, shooting at ultra-fast shutter speeds (1/16000s to 1/32000s) allows you to capture the entirety of that incredibly brief burst of light. This means a global shutter allows you to hit that 1-stop brightness advantage at just 1/8 power or even 1/16 on a highly optimized speedlight like the Sony F28RM/A.
Using the ND workaround, you are forced to dump your flash at a full 1/1 power pop to get max brightness. That makes the global shutter approach 3 to 4 stops more efficient on top of the raw output gain.
The Real-World Impact 🎒 This lack of efficiency is exactly why photographers have traditionally hauled around massive, heavy strobes, simply to avoid shooting at full power all the time. But with a global shutter, you are only sipping 1/8 or 1/16 power, which completely transforms the shooting experience. Instead of waiting on your flash, you get near-instant recycle times, minimal heat buildup, effortless burst firing, dramatically longer battery life, and rock-solid color consistency from the first shot to the last.
When you add it all up, you are looking at a 4- to 5-stop overall advantage over the traditional ND workaround, the efficiency equivalent of jumping from a 100Ws strobe to a massive 3200Ws pack. Both Sony’s published data and my own real-world testing confirm this.
For controlled indoor studio shots, I still keep my AD600 around. But for on-location work, I no longer need to drag heavy setups out into the field. I can handle almost any bright, midday situation with just the F28RM/A, pound for pound, the best output-to-weight setup on the market right now.
...Show more →
I'm not understanding that logic. A F28RM/A is still a wimpy little flash. The GN does not get any better due to having a very fast synch speed. All it does is reduce the ambient light. I suppose you are at high ISO with a very fast lens, close range and no modifiers? At full power and 50mm that flash only is rated at GN 92 feet at ISO 100, which would be nowhere near that outdoors; let's assume it's 68. At 1/8 power that is about GN 24 feet. It may work in some scenarios, but people still want more flash power much of the time. Would you use that flash at night where the synch speed is no longer an issue?
EBH
|
