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Old Apr 11, 2006, 7:41 PM   #1
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Does anyone know how long the flash lasts at 1/16 power on these flashes? Any numbers on any comparable flashes? How about at 1/64 on a Sunpak 5xx?



Thanx - Chuck
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Old Apr 11, 2006, 9:51 PM   #2
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cgbraggjr wrote:
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Any numbers on any comparable flashes?
Metz 45CL/CT-4:

Full: 1/300 sec
1/2: 1/1000 sec
1/4: 1/2500 sec
Winder mode: 1/10 000 sec
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Old Apr 11, 2006, 9:59 PM   #3
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It's going to vary by flash, and it might be hard to find the numbers for the Sunpaks without a manual.

Checking the specs in the manual for a Sunpak 333 I've got, it shows the flash duration running from 1/1200 second to 1/20,000 second. This one doesn't have a 1/64 power setting (lowest is 1/16 power).

The GN on my 333 Auto runs from 86 to 120 feet, depending on the zoom head position. So, it's probably not too far off from the Sunpak 422 and 433 from a flash duration perspective.

BTW, you can't see the second line of your forum post (mentioning the 422 and 433) unless you're viewing the list of posts in this forum. That's one of the "quirks" I don't like about the WowBB software we use for the forums.


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Old Apr 14, 2006, 12:52 AM   #4
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Thanks responders. It looks as if I can do some hummingbird wing-stopping at 1/16 power.
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Old Apr 14, 2006, 1:00 AM   #5
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cgbraggjr wrote:
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Thanks responders. It looks as if I can do some hummingbird wing-stopping at 1/16 power.
Your KM DSLR has a fastest flash sync speed of 1/180 second with AS off or 1/125 second wth AS on.

So, I'm not so sure it's going to help with hummingbirds, unless you plan on using it in darker conditions so that ambient light isn't contributing as much to the exposure (or you're going to use it with a different camera without sync speed limitations).

P.S.

I responded to your post asking about using a flash like this on a KM DSLR:

http://www.stevesforums.com/forums/v...mp;forum_id=84

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Old Apr 22, 2006, 1:04 AM   #6
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Jim wrote, "So, I'm not so sure it's going to help with hummingbirds, unless you plan on using it in darker conditions so that ambient light isn't contributing as much to the exposure (or you're going to use it with a different camera without sync speed limitations)."

Oh yes, it has to be done in low enough light that the flash is virtually all the lighting. I have an old 5600HS to use in 1/16 manual mode to trigger slaves in 1/16 manual mode as well. Taking your cue I've bought some Sunpaks on ebay (stole a 333 for $6.50!!) and took a chance on three Sonia slave units that seem to be fine. When the other flashes arrive I'll be doing a *lot* of testing but others have done it, so .....
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Old May 13, 2006, 6:05 PM   #7
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You can measure the flash duration using an electric motor. Take a regular induction motor, for instance a 4 pole motor that turns at 1750 rpm. Glue onthe front of the motorpulley a black card disc with a white radial line (a very narrow white paper strip glued on it). Shoot a photo of it in the dark with the motor runing. The photo will show a blurred white sector, the angle of it will reveal the flash duration. If the motor turns at 1750 rpm it is 29,2 turns per second so it is 10512 degrees per second. If the sector in the photo is 10.2 degrees the flash duration is 1/1000 sec.Easy isn't it? A two pole motor would give better accuracy because it turns at 3500 rpm. If you have doubts please ask me and I can clarify.

Using my Sony R1 it is easier because it syncronises the flash up to1/2000 s.



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