Help with black line in photo

rajmohan99

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Name
Rajmohan
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Dear all,
I tried to take some portraits of my wife yesterday.
The set up was
1) 2 soft boxes (5400K)
2) 1 flash 380EX against a reflective brolly
3) 1 430 ex straight on
4) Used wireless flash triggers PT-04C
exposure time 1/500 Secs
f-number- 5.6
metering mode -spot
exp compensation-0

Some of the photos came fine, some had a balck band as though it is underexposed.
Why is it that way, or is it due to something else.:thinking:
Sorry I was unable to load the photo itself.
Any help or suggestion is highly appreciated.
Cheers.:thumbs:
R
 
looking at your data .i would guess your shutter speed is set too high.Might be wrong
 
Me too. Theres no need to go that high. I usually go at 1/250 sec
 
looking at the info you posted it is simply a case that you have set the shutter speed to fast and you the black band is the shutter curtain showing i the picture.
 
Flash synch speed on the 40D (and lots of other cameras) is 1/250th or less.
 
Edit: Oops! Crossed post with David ;)

Max flash sync speed on a 40D is 1/250sec. Google focal plane shutter to see why this is, and why the bottom of the picture goes black if you go higher. Anything longer is fine though.

Two more things, those particular radio triggers introduce a slight delay in firing, so you need to run slower than the normal 1/250sec when using them. You should be okay at 1/160sec but use 1/125sec just to be sure. It makes no odds.

The other thing is that your flash also has a High Speed Sync mode that you can use with higher shutter speeds. It pulses the flash very rapidly to simulate continuous light just long enough for the shutter to complete a full normal cycle. (You will understand that after googling ;) )

There's no point in using this feature in a studio situation but it's handy for fill flash outdoors in bright light when you might want to use 1/1000sec or something with flash. It wastes a lot of light though, so range is reduced and it will increase the recycle time in most situations (and run down the batteries) but is invaluable when you need it. Handbook explains.
 
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