half image dark, half light issues

When shooting a wedding this summer, I got some bizarre shots with my EOS 1V using 17-40 lens at 4.0.

 

The day was a bit overcast and I got three categories of b x w prints:

 

1. prints that made the day suddenly turned to night -- looked as if the poolside reception was happening

at 10 pm rather than 2 pm

2. half the shot would turn out darkened or completed whited out -- for example the left half or right half

would darken or whiten

3. prints were great -- no shadows, no darkening.

 

I've posted a shot related to #2 issue and wonder if anyone can help me figure out what went wrong. The

first issue is I think due to using a flash when the light was too ambient or diffuse. So best to use it for fill

I suppose?<div></div>

Ok, I posted my anser in the last thread, but the picture is in this duplicate thread. It looks like something is blocking your flash. It could be a large lens if your lens is large and you were shooting at a wide angle, or it could be your hand which is wrapped around your lens, in the way of your falsh. So, when the flash fired, it was hitting your lens or hand creating a shadow on the person. Do you think that could be?

I think the light is the harsh flash, and the other side is a shadow from something blocking your flash like I just posted. I don't think the light is the problem (besides the fact that it is too harsh), the shadow is.

Looks like you were using a flash fill with your shutter speed set higher than your camera will allow for proper flash synch. No great mystery here. The shadow is the curtain of the focal plane shutter caught part way across the opening. If, for example, your camera only syncs at a max of 1/125 and you shot with a shutter speed of 1/250 to properly expose for daylight, the image would have half of the exposure by daylight only and the other half part daylight and part flash.

Mark's right. Your shutter was closing as your flash was firing.

 

Double-check the sync speed for your camera. Most cameras sync at 1/250th, though some

cameras cap off at 1/60th.

Since this is a verticle, and in reality the flash is on the bottom half of your image, it looks like you were shooting above your camera/flash sync speed. If you can get exif info, check what your shutter speed was, I'd almost guarantee it was your sync speed

Sync speed error, or a mis-pointed flash.

I lean towards Kari's answer. The line between the light and dark areas is curved -- if this was a sync issue the line would be straight.

Could it be that you were bouncing your flash off the ceiling, and turned the camera to vertical without adjusting the flash position (thus sending the flash at a 45 degree angle to the left)?

This is clearly a shadow of something between the flash and subject. Look at the shadow on the girl's arm - it follows the curve of her arm - it's not a sync speed error.

However, I don't think it would be your hand either - the edge of the shadow is too sharply defined for that.

Can you think of anything else that could have caused a shadow?

a flash bracket would help eliminate this problem if you did not use one, but as with every other response check your sync.

looks like flash sync issue. slow your shutter down.

 

if you don't know your shutter sync speed, you can test it with a small P&S digital camera. I'll leaveit up to you to thinik about how...hint - long exposure.