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Photography Question 
Robyn Gwilt
BetterPhoto Member Since: 7/15/2005
 

2nd curtain flash


Someone suggested I used 2nd curtain flash outdoors (especially at weddings)- i.e. let the camera expose correctly, and the flash 'fill-in'. Are there any other situations where its a 'must'? Do I need to set the camera and the flash to 2nd curtain? I'm using a Canon 30D and 580EX flash. Or do I just set the flash so that the > > > shows, which denots 2nd curtain. Thanks


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3/6/2007 12:16:59 AM

 
Jon Close
BetterPhoto Member Since: 5/18/2000
  2nd curtain flash and fill flash are 2 separate concepts, but they can be done together. The shutter speed does not affect the exposure of the near subject lit by the flash, but does limit the amount of ambient light recorded. Typical flash shots are done with a relatively high shutter speed of 1/60 to 1/500. In typical dimly lit indoor shots this makes for a well lit near subject but a near-black background. So one can set a slower shutter speed in Av or M modes to give more exposure to the background (putting your subject "in context"), and the 580EX flash output will automatically adjust to give fill flash that won't "blow out" your subject.

Slow shutter speeds will not freeze moving subjects, even with flash. Normally the flash fires just as the shutter curtains open (1st curtain sync). Any subject movement streaking/blur captured by the long shutter speed will appear in front of the subject captured by the flash. Set the flash for 2nd curtain sync and this blur will appear to more naturally trail the subject.


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3/6/2007 6:04:19 AM

 
Jon Close
BetterPhoto Member Since: 5/18/2000
  oops, P.S.
With the 580EX set to the defaults, then you can select 2nd curtain sync using the 30D's custom function 15. This is most useful with the built-in flash or speedlights that do not have controls for setting the sync. You can also set it directly on the 580EX, in which case it will override whatever setting is on the camera. The setting on the 580EX may be preferred since it is a bit quicker to turn on/off, and the 580EX's LCD display gives a constant reminder how it is set.


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3/6/2007 6:09:57 AM

 
Robyn Gwilt
BetterPhoto Member Since: 7/15/2005
  Thanks Jon (quite late here, so I had to read it a few times!) So, if my camera/flash sync is 1/60s, (1st curtain) I should get enough ambient light and not blow the subject - so actually if I just leave it on '0' (flash) and don't under/over compensate, (ETTL) I should get good hand held pix - any slower, and I should use tripod, and make sure the subject is really standing still? Or do I select the 2nd curtain for outside and go back to first curtain on inside. Re the camera setting - I'll leave it on 1st curtain, and just use the flash button to overide? (I'm talking mainly wedding flash here btw) Low light, slow moving, but still moving subjects. Thanks. Will check back in the morning!


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3/6/2007 12:32:15 PM

 
Who Me? 
BetterPhoto Member Since: 1/19/2007
  I certainly hope the 30D is your back-up. The higher end wedding photographers use the 5D or MarkII and up. The 2nd curtain is good for certain effects, just make sure you get the shot before you start screwing around with the buttons.

Take it lite


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3/7/2007 8:49:19 PM

 
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