What are the flash durations at the various power levels for the 600EX-RT?

[JohnGerlach]

Most flash makers publish the flash durations for the various power levels in the manual, but Canon does not.  When photographing very high speed action, such as hummingbird wings, it is important to have the flash durations quite close to avoid ghosting.  It would be nice to be able to mix various flashes, so it would be helpful to know the flash durations.  Anyone know where this info is published?  I am curious to know if the flash durations for the 430, 600, and perhaps even the 580 II are close enough.  I could try it, but sometimes I must mix Canon speedlites with other flash brands.  Here is a male rufous hummingbird using 1/32nd power on manual.  Five 600's were used.

[Peter]

Output level	Manufacturer spec	t0.1 metering
1/1	1/833	1/285
1/2	na	1/1400
1/4	na	1/2800
1/8	na	1/4600
1/16	na	1/6500
1/32	na	1/7500
1/64	na	<1/8000
1/128	na	<1/8000

Is that what you mean? 580II EX.

This numbers below are measured from a photodiod. 580 EX.

1/1 power = 1/1000 second
1/2 power = 1/2000
1/4 power = 1/4000
1/8 power = 1/9000
1/16 power = 1/15000
1/32 power = 1/21000
1/64 power = 1/30000
1/128 power = 1/35000

[JohnGerlach]

Thanks so much!  This will give me some help in pairing up different speedlites.

[Peter]

The two speedlites have been different measured. The first one with t0,1.

t0.1 duration i.e. the time between 10% of the maximum intensity is reached and back down to 10% towards the end of the flash discharge,

The 580EX has been measured just by a photocell.

[Peter]

430exII

Output level	Manufacturer spec	t0.1 metering
1/1	na	1/350
1/2	na	1/1630
1/4	na	1/3000
1/8	na	1/4300
1/16	na	1/5250
1/32	na	1/5600
1/64	na	1/6500

[JohnGerlach]

I don't think I can trust this data.  I know when I see the flash durations posted by Nikon and Sunpak in their flash manuals, the durations are much shorter in the 1/16 to 1/64 power range.  Something isn't right.  I was hoping someone has seen where Canon has posted this info somewhere.  I have asked Canon to put this info in their manuals, but they don't get the need for it and so far my requests have done no good.  Thanks for trying!

[JohnGerlach]

For example, here are the flash durations for the Nikon SB-910.  Notice how short the duration is at 1/16 and 1/32 power.

Flash duration

1/880 sec. at full output.

1/1,100 sec. at M 1/2 output.

1/2,550 sec. at M 1/4 output.

1/5,000 sec. at M 1/8 output.

1/10,000 sec. at M 1/16 output.

1/20,000 sec. at M 1/32 output.

1/35,700 sec. at M 1/64 output.

1/38,500 sec. at M 1/128 output.

[Peter]

SB-700 Flash Duration Times

The next table shows specs versus test result for all full stops down to 1/128, as far as the measurement device could capture the durations (the metering range ends at 1/8000 seconds).
 

Output level	Manufacturer spec	t0.1 metering
1/1	1/1042	1/305
1/2	1/1136	1/1000
1/4	1/2857	1/2300
1/8	1/5714	1/4000
1/16	1/10000	1/5250
1/32	1/18182	1/8000
1/64	1/25000	<1/8000
1/128	1/40000	<1/8000

While the results are similar to the SB-600, they differ a lot from the data in the official Nikon table in section H-17 of the instruction manual. Overall, what’s probably most relevant to note here is that the speedlight’s 1/1 flash duration is in line with other model of accessory flash.

...

t0.5 is the time between the moment where the flash intensity curve starts to exceed 50% of the maximum intensity point and the moment where the falling intensity curve goes underneath the 50% maximum level again. The t0.5 time is shorter by definition and therefore used by most manufacturers, e.g. Nikon.

[JohnGerlach]

I guess I will just do what I always do and use the same flash units when doing high speed action photography.  I know if I set 1/16, and now use primarily 1/32 power levels, the short duration freezes hummer wings quite nicely.  I learned about the problem of mixing flash durations several years ago when I used 1/16 power on the hovering hummers while I set the flash lighting the background to 1/4 power to light a larger area evenly.  I got a dark edge along the wings and wondered what was causing it for a few days.  Eventually, I realized the 1/16 power flashes on the hummer freeze the wings, but the longer flash duration used by the background flash was still lighting the background once the lights on the bird had done its job.

In the first image the female black-chin is lit primarily with ambient, but some fill flash is used.  The male calliope wings are allowed to blur with all flash by using 1/2 or 1/4 power levels.  The third image is all flash at 1/32 power to freeze motion, and finally is the setup from last year.  I made major improvements this year to the setup so it works a lot better to produce better poses and colors in the gorget.

.  The wings moved a little preventing some of the background from being properly exposed because the wings were blocking a sliver of the background that was still being lit.

Freezing the wings is only one way to photograph hummers.  I do use all ambient light a lot, sometimes mix ambient and flash, and even blur the wings with all flash by using 1/2 or 1/4 power as the longer flash durations at these power levels don't freeze the wings producing a more natural looking hummer.  You can tell I spend way too much time with hummingbirds!

[diverhank]

@JohnGerlach wrote:

Freezing the wings is only one way to photograph hummers.  I do use all ambient light a lot, sometimes mix ambient and flash, and even blur the wings with all flash by using 1/2 or 1/4 power as the longer flash durations at these power levels don't freeze the wings producing a more natural looking hummer.  You can tell I spend way too much time with hummingbirds!

---

I respect what you're doing but I don't like to see frozen wings on hummingbirds...they look like taxidermy specimens being hung up.  I also dislike the look of flash on birds in general and especially hummingbirds.

I never use flash on hummingbirds and many have bought my pictures so freezing the wings... it's not the only way to go :).  Edit: sorry I misread your post, I thought you said freezing the wings is the only way...you actually said only one way...

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