Short flash duration vs high speed shutter/HSS flash

dfp771 · 08-26-2016, 02:11 PM - **2 Likes**

I wanted to compare two methods for freezing action in a controlled environment (studio). I took three pictures. The first picture (2343) uses a Metz 52-AF1 flash @ full power through a Westcott 43" 1 stop diffuser backlighting a ice cube falling in a small bowl/vase of water. It is triggered with a Cactus V6 II (two, 1 Tx, 1 Rx) in normal/HSS mode. The camera is a Pentax K-1 with a 77mm 1.8 limited lens, 1/8000 sec, f8, ISO 800.

The second picture (2355) uses a Elinchrom ELB400 with a Quadra HS head @ full power (424 J) using port A being triggered with a Cactus V6 II (two, 1 Tx, 1 Rx) in normal/HSS mode with the receiver set to Manual Flash system and connected to the external sync socket of the ELB400. This picture was taken at 1/8000, f8, ISO 100.

The third picture (2361) uses a Elinchrom ELB400 with a Quadra "Action" head @ 27 J (- 4 stops from full power) using port B being triggered by the same pair of Cactus V6 IIs. This flash head is spec'd at a flash duration (t 0.5) of 1/5700 sec @ 140 J (1/3 power, port B). This picture was taken at 1/200, f8, ISO 100.

I don't see a big difference in the three pictures. I should have used f16 instead of f8 to give more depth of field. But the action freezing capability appears about the same. Please note that, using the action head, to get the same exposure the flash power is lower by 4 stops vs HSS flash! The Elinchrom HS head has a relatively long flash duration of 1/550 sec. The useful power, on location, in the sun of the ELB400 vs the Metz 52-AF1 appears to be about right (3 stops difference). I like having the ability to freeze action in bright sun and/or control ambient exposure with the ELB400 and the HS head using HSS. I did try the "Powersync" mode with the Cactus triggers with the ELB400 and HS head. I noticed a 1 stop loss in flash power vs normall/HSS mode. I also tried port B on the ELB400 with the HS head and noted severe banding/ light gradients at any shutter speed above 1/200 sec. So with port A on the ELB400 I still have 4 stops of flash power range when using HSS which should be fine- you need as much power as possible when shooting action in the sun.

You can see the full res photos here:
Short flash duration vs high shutter/HSS flash - Images | David F Parker Photography

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hcc · 08-26-2016, 04:12 PM - **1 Like**

Nice shots. Thank you for sharing and posting your results.

On the topic of high-shutter speed, I take photographs of droplets and bubbles in a research environment. Photographs are taken in high-speed flows (V = 2 to 8 m/s). I am generally not very happy with flash because of lack of control. I found that I have the best control of the photography using a strong LED light allowing to set the shutter at 1/8,000s. The lighting is High Power 24 LED Lamp 100 W. Using the manual mode, I would set the shutter speed, aperture (1.4 to 4 depending upon applications) and ISO (200-1600).

Two examples are listed below. For scale, each needle is about 1 mm in diameter.

dfp771 · 08-26-2016, 04:43 PM

Nice photos, especially considering the water velocity and the magnification! Theoretically, strobes can be very fast with durations of less than 1/20,000 second. The problem is the power level is way too low, though. The right strobes can stop a bullet, though. See the founder of strobe photography, Harold Edgerton...

hcc · 08-26-2016, 11:34 PM

Originally posted by dfp771

Nice photos, especially considering the water velocity and the magnification! Theoretically, strobes can be very fast with durations of less than 1/20,000 second. The problem is the power level is way too low, though. The right strobes can stop a bullet, though. See the founder of strobe photography, Harold Edgerton...

dfp771, you are correct: strobe could be an alternative, but lighting remains a challenge.

In the case of bubbles, as shown earlier in the thread, a major challenge was the lighting conditions constantly changing with the light reflections from the bubble-droplets interfaces. The photos shown were slightly cropped (~50%).

Class A · 08-27-2016, 05:15 AM

Originally posted by dfp771

Nice photos, especially considering the water velocity and the magnification! Theoretically, strobes can be very fast with durations of less than 1/20,000 second. The problem is the power level is way too low, though.

The trick is to use many flashes / strobes to compensate for the low power output at short flash durations. Quite a gear-intensive solution, though.

Originally posted by dfp771

I did try the "Powersync" mode with the Cactus triggers with the ELB400 and HS head. I noticed a 1 stop loss in flash power vs normall/HSS mode.

That is strange and I suspect that you could reverse the situation by tweaking the PowerSync timing adjustment on the V6II.
After selecting "PowerSync", press OK and turn the dial while keeping OK pressed. Alternatively, you can also just turn the dial while keeping it pressed in. This will invoke the PowerSync timing adjustment feature and by playing with the value, you might find a setting where the output from the flash is at least as high it is for "Normal HSS". With a non-HSS head, you should be able to get higher output when using PowerSync (at the cost of a graduated exposure).

Originally posted by dfp771

I also tried port B on the ELB400 with the HS head and noted severe banding/ light gradients at any shutter speed above 1/200 sec.

Apparently the ELB400 does not provide a HSS-type output then, when port B is used. No idea, whether this is by design.

The only way to avoid black bars for shutter speeds above 1/200s is to make the head emit an HSS-type burst or use PowerSync in combination with power levels in which flash duarations are not shorter than 1/200s.

dfp771 · 08-27-2016, 09:59 AM

Originally posted by Class A

The trick is to use many flashes / strobes to compensate for the low power output at short flash durations. Quite a gear-intensive solution, though.

That is strange and I suspect that you could reverse the situation by tweaking the PowerSync timing adjustment on the V6II.
After selecting "PowerSync", press OK and turn the dial while keeping OK pressed. Alternatively, you can also just turn the dial while keeping it pressed in. This will invoke the PowerSync timing adjustment feature and by playing with the value, you might find a setting where the output from the flash is at least as high it is for "Normal HSS". With a non-HSS head, you should be able to get higher output when using PowerSync (at the cost of a graduated exposure).

Apparently the ELB400 does not provide a HSS-type output then, when port B is used. No idea, whether this is by design.

The only way to avoid black bars for shutter speeds above 1/200s is to make the head emit an HSS-type burst or use PowerSync in combination with power levels in which flash duarations are not shorter than 1/200s.

Class A,
I'll try your suggestion and tweak the Powersync timing adjustment to see if this will improve the output. Regarding using Port B on the ELB400, Elinchrom specs the flash duration of Port B using the HS head as 1/1100 sec which is too short, I believe. (The A Port has the longer flash duration of 1/550 sec with the HS head).

dfp771 · 08-27-2016, 06:38 PM

Originally posted by dfp771

Class A,
I'll try your suggestion and tweak the Powersync timing adjustment to see if this will improve the output. Regarding using Port B on the ELB400, Elinchrom specs the flash duration of Port B using the HS head as 1/1100 sec which is too short, I believe. (The A Port has the longer flash duration of 1/550 sec with the HS head).

Class A,
I did adjust the powersync timing with the HS head on Port A of the Elinchrom ELB400. Instead of a 1 stop loss I now have a 2/3 stop gain in output vs Normal HSS. This is the mode I will leave it in when shooting with the HS head. Now the output of the flash is linear from 1/200 sec with the Action head all the way up to 1/8000 sec using the HS head in "Powersync" or "Hi-Sync" mode. (For every stop increase in shutter speed- 1/500 to 1/1000 sec, I see a one stop loss in flash output.) I can use the HS head from 1/250 sec up to 1/8000 second from 27J to 424J. At 1/200 second and below, the Action head works best triggered in Normal mode with the Cactus triggers. I tried the HS head @ 1/200 sec and I see banding so I won't use it in normal mode. Thanks!

Class A · 08-28-2016, 01:14 AM - **1 Like**

Originally posted by dfp771

Instead of a 1 stop loss I now have a 2/3 stop gain in output vs Normal HSS. This is the mode I will leave it in when shooting with the HS head.

Glad my suggestion worked.

dfp771 · 08-28-2016, 02:13 PM

FYI, My Powersync timing adjustment is set to 9 for optimal output and no banding.

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08-26-2016, 04:43 PM	#3
dfp771 Forum Member Join Date: Nov 2014 Location: Monterey County, California Photos: Albums Posts: 97 Original Poster	Nice photos, especially considering the water velocity and the magnification! Theoretically, strobes can be very fast with durations of less than 1/20,000 second. The problem is the power level is way too low, though. The right strobes can stop a bullet, though. See the founder of strobe photography, Harold Edgerton...

08-26-2016, 11:34 PM	#4
hcc Pentaxian Join Date: Nov 2009 Location: Brisbane, Australia Photos: Gallery \| Albums Posts: 4,005	Originally posted by dfp771 Nice photos, especially considering the water velocity and the magnification! Theoretically, strobes can be very fast with durations of less than 1/20,000 second. The problem is the power level is way too low, though. The right strobes can stop a bullet, though. See the founder of strobe photography, Harold Edgerton... dfp771, you are correct: strobe could be an alternative, but lighting remains a challenge. In the case of bubbles, as shown earlier in the thread, a major challenge was the lighting conditions constantly changing with the light reflections from the bubble-droplets interfaces. The photos shown were slightly cropped (~50%).

08-27-2016, 05:15 AM	#5
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by dfp771 Nice photos, especially considering the water velocity and the magnification! Theoretically, strobes can be very fast with durations of less than 1/20,000 second. The problem is the power level is way too low, though. The trick is to use many flashes / strobes to compensate for the low power output at short flash durations. Quite a gear-intensive solution, though. Originally posted by dfp771 I did try the "Powersync" mode with the Cactus triggers with the ELB400 and HS head. I noticed a 1 stop loss in flash power vs normall/HSS mode. That is strange and I suspect that you could reverse the situation by tweaking the PowerSync timing adjustment on the V6II. After selecting "PowerSync", press OK and turn the dial while keeping OK pressed. Alternatively, you can also just turn the dial while keeping it pressed in. This will invoke the PowerSync timing adjustment feature and by playing with the value, you might find a setting where the output from the flash is at least as high it is for "Normal HSS". With a non-HSS head, you should be able to get higher output when using PowerSync (at the cost of a graduated exposure). Originally posted by dfp771 I also tried port B on the ELB400 with the HS head and noted severe banding/ light gradients at any shutter speed above 1/200 sec. Apparently the ELB400 does not provide a HSS-type output then, when port B is used. No idea, whether this is by design. The only way to avoid black bars for shutter speeds above 1/200s is to make the head emit an HSS-type burst or use PowerSync in combination with power levels in which flash duarations are not shorter than 1/200s.

08-27-2016, 09:59 AM	#6
dfp771 Forum Member Join Date: Nov 2014 Location: Monterey County, California Photos: Albums Posts: 97 Original Poster	Originally posted by Class A The trick is to use many flashes / strobes to compensate for the low power output at short flash durations. Quite a gear-intensive solution, though. That is strange and I suspect that you could reverse the situation by tweaking the PowerSync timing adjustment on the V6II. After selecting "PowerSync", press OK and turn the dial while keeping OK pressed. Alternatively, you can also just turn the dial while keeping it pressed in. This will invoke the PowerSync timing adjustment feature and by playing with the value, you might find a setting where the output from the flash is at least as high it is for "Normal HSS". With a non-HSS head, you should be able to get higher output when using PowerSync (at the cost of a graduated exposure). Apparently the ELB400 does not provide a HSS-type output then, when port B is used. No idea, whether this is by design. The only way to avoid black bars for shutter speeds above 1/200s is to make the head emit an HSS-type burst or use PowerSync in combination with power levels in which flash duarations are not shorter than 1/200s. Class A, I'll try your suggestion and tweak the Powersync timing adjustment to see if this will improve the output. Regarding using Port B on the ELB400, Elinchrom specs the flash duration of Port B using the HS head as 1/1100 sec which is too short, I believe. (The A Port has the longer flash duration of 1/550 sec with the HS head).

08-27-2016, 06:38 PM	#7
dfp771 Forum Member Join Date: Nov 2014 Location: Monterey County, California Photos: Albums Posts: 97 Original Poster	Originally posted by dfp771 Class A, I'll try your suggestion and tweak the Powersync timing adjustment to see if this will improve the output. Regarding using Port B on the ELB400, Elinchrom specs the flash duration of Port B using the HS head as 1/1100 sec which is too short, I believe. (The A Port has the longer flash duration of 1/550 sec with the HS head). Class A, I did adjust the powersync timing with the HS head on Port A of the Elinchrom ELB400. Instead of a 1 stop loss I now have a 2/3 stop gain in output vs Normal HSS. This is the mode I will leave it in when shooting with the HS head. Now the output of the flash is linear from 1/200 sec with the Action head all the way up to 1/8000 sec using the HS head in "Powersync" or "Hi-Sync" mode. (For every stop increase in shutter speed- 1/500 to 1/1000 sec, I see a one stop loss in flash output.) I can use the HS head from 1/250 sec up to 1/8000 second from 27J to 424J. At 1/200 second and below, the Action head works best triggered in Normal mode with the Cactus triggers. I tried the HS head @ 1/200 sec and I see banding so I won't use it in normal mode. Thanks!

08-28-2016, 01:14 AM - 1 Like	#8
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by dfp771 Instead of a 1 stop loss I now have a 2/3 stop gain in output vs Normal HSS. This is the mode I will leave it in when shooting with the HS head. Glad my suggestion worked.

08-28-2016, 02:13 PM	#9
dfp771 Forum Member Join Date: Nov 2014 Location: Monterey County, California Photos: Albums Posts: 97 Original Poster	FYI, My Powersync timing adjustment is set to 9 for optimal output and no banding.