| Author |
Message |
    
Robert
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 15, 2004 - 09:32 am: | 
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Could anyone lend an answer to me regarding the following problem.
While doing a studio shoot, all my film came back half exposed. I mean literally half of the print looked correctly exposed, the other half was black. What could be causing this? |
Martin
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 15, 2004 - 10:11 am: |
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Check the shutter sync speed of your camera. You don't specify details but I'm guessing you were using strobes not continuous "hot lights". The effect you describe sounds like the typical result when you set the shutter speed too fast. What you're seeing is the shutter not being fully open when the stobe fires.
Most mechanical SLRs that don't have leaf shutters sync at 1/125. Older examples at 1/60 or even 1/30. More modern cameras at 1/250 or better. Leaf shutter cameras (a lot of fixed lens rangefinders and expensive medium format equipment) do not have this limitation and often sync with strobes at all shutter speeds. If you have set your camera to the correct flash sync speed and you still see this effect it may be that you camera needs an CLA.
Regards - Martin |
Jim Brokaw
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 15, 2004 - 11:25 pm: |
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The sync speed seems to be the key here. If you set 1/125 on a camera with a 1/60 sync speed, you will get about 1/2 frame blacked out. Higher speeds will black out more of the frame.
Typically the sync speed is 1/60 for horizontal cloth focal-plane shutters and 1/90 or 1/125 for vertical metal multi-leaf focal plane shutters (e.g. Copal Square, etc). The can be found just by looking at the shutter.
Using a slower than specified sync speed won't hurt anything, except if it lets ambient light (non-flash) influence the exposure. Indoors this probably won't be a problem if you use 1/30 for everything flash. |
Roland F. Harriston
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 17, 2004 - 08:39 am: |
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Focal plane shutter "capping"?
Roland F. Harriston |
