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Archive 2011 · ~1/200th limit with bees/cybersyncs
  
 
RoadconePhoto
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p.1 #1 · ~1/200th limit with bees/cybersyncs


so, which part is the limitation... supposedly the cybersyncs trigger in like 1/4000th of a sec and the bee fully discharges in something ike 1/4100th... yet anything over 1/200th will outrun the strobe.


Dec 13, 2011 at 02:45 PM
cgardner
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p.1 #2 · ~1/200th limit with bees/cybersyncs


Neither....

There is latency between the time the transmitter gets the "fire" signal from the camera, sends it to the receiver, it tells the light to fire, and the power reaches the flash tube and it ignites.

What is happening is the second curtain of the shutter is already closing by the time the flash goes off creating the shadow over the sensor.

If you look in your camera manual in the section on manual flash you will note the specified sync speed is for a speedlight in hot shoe. It mentions slower speed are needed for studio lights.

If you keep your ambient lighting low and don't have a lot of subject movement 1/160th or slower shutter will work fine because the flash duration stops the action. With very rapid movement, such as a spinning dancer, the problem stopping the motion with studio lights is that the flash duration is too long to freeze the action.



Dec 13, 2011 at 02:55 PM
kenyee
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p.1 #3 · ~1/200th limit with bees/cybersyncs


The limitation is your camera...what are you using?

If it's a normal DSLR, you have a mechanical shutter curtain that moves across the sensor...it's mechanical so it's speed limited to whatever your x-sync speed is (which is probably 1/200 )

p.s., if you use a P&S w/ a hotshoe, you can get higher sync speeds since they don't have this mechanical shutter. Ditto the Nikon D40/D70 DSLRs, but they're not the norm...




Dec 13, 2011 at 03:06 PM
saelee
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p.1 #4 · ~1/200th limit with bees/cybersyncs


I am guessing you are shooting a Canon.

The limit is on your camera not the trigger.

I can get 1\250 sec with my d700. I can get 1/2,000 sec with my d40 and my panasonic lx5 pns.



Dec 14, 2011 at 12:30 AM
 

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sic0048
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p.1 #5 · ~1/200th limit with bees/cybersyncs


saelee wrote:
I am guessing you are shooting a Canon.

The limit is on your camera not the trigger.

I can get 1\250 sec with my d700. I can get 1/2,000 sec with my d40 and my panasonic lx5 pns.


You make it sound like it is a Canon problem which it is not - every mechanical shutter has a fairly similar sync speed limitation. Yes some are speced to be 1/250th and others only 1/200th but those speeds are also written assuming you are using the brands dedicated speedlights. I bet that your actual sync speed using a wireless trigger and a strobe will be less than the printed 1/250th max sync speed due to the extra delay that a trigger can introduce into the system



Dec 14, 2011 at 05:08 PM
saelee
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p.1 #6 · ~1/200th limit with bees/cybersyncs


sic0048 wrote:
You make it sound like it is a Canon problem which it is not - every mechanical shutter has a fairly similar sync speed limitation. Yes some are speced to be 1/250th and others only 1/200th but those speeds are also written assuming you are using the brands dedicated speedlights. I bet that your actual sync speed using a wireless trigger and a strobe will be less than the printed 1/250th max sync speed due to the extra delay that a trigger can introduce into the system


I understand that the limit is from the mechanical shutter on the camera. But in general, Canon tend to have a harder time syncing at rated sync speed compared to nikon bodies when you take the flash OFF camera.

http://strobist.blogspot.com/2010/01/know-your-sync.html

I am not here to debate about Canon vs Nikon. Sorry if my first statement sounded like I am attacking Canon.



Dec 15, 2011 at 12:10 AM
BrianO
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p.1 #7 · ~1/200th limit with bees/cybersyncs


RoadconePhoto wrote:
so, which part is the limitation... supposedly the cybersyncs trigger in like 1/4000th of a sec and the bee fully discharges in something ike 1/4100th... yet anything over 1/200th will outrun the strobe.


As stated above, the problem lies with the way shutters work.

At or below the maximum sync speed -- whether that be 1/250, 1/200, 1/125, or whatever -- the first curtain fully opens, exposing the sensor, then the flash fires its very brief pulse, then the second curtain closes, covering the sensor. A faster shutter speed doesn't mean that the curtains are moving faster, only that the delay between first curtain opening and second curtain closing is shorter.

But above sync speed, the curtains can't move fast enough to do the job, so instead the second curtain starts to close before the first curtain is fully open, creating a moving slit that "wipes" across the sensor, exposing any given part of the sensor for the correct time for the shutter speed set.

That works great in sunlight or continuous artificial light, but when using flash it doesn't; the brief burst of light from the flash will only hit the part of the sensor that's under the slit at the moment it fires.

Trigger latency can be an issue when operating just a bit above sync speed, because sometimes slow-acting strobes can be timed to fire in such a way that they stay at a relatively steady brightness as the curtains move across the sensor, but only if the timing is precise and usually only at low power settings with voltage-controlled strobes. Speedlites and IGBT/thyristor-controlled strobes work differently, and lower power settings will actually shorten the flash duration, making out of sync shutter speeds worse instead of better.

There are a few ways to get around the sync speed issue. The two most common are use of leaf-shutter lenses that can open and close at speeds of 1/500 to -- in the newest models -- 1/1600, or the use of High Speed Sync (Canon's term), Focal Plane Flash (Nikon's term), or other similar methods, where the Speedlite/Speedlight/flash gun is fired multple times in short succession (at vastly reduced power) to simulate continuous light during the entire shutter travel.

Some point and shoot cameras, and a few DSLRs, use an electronic "shutter" rather than an actual physical shutter, and they don't have the same sync speed issues because the sensor is always exposed; the sensor is just switched on and off electronically to simulate a given shutter speed. There are also "hybrid" designs that only have one curtain. Both of those systems have other issues, though, which is why most DSLRs still use a traditional mechanical shutter.

Lot's of info here, but hopefully it helps or at least points you in the right direction for further reading.



Dec 15, 2011 at 05:10 AM





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