Flash Shadows

Discussion in 'Lighting' started by anyte, Jul 11, 2004.

  1. anyte

    anyte Member

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    Sorry if this is the wrong forum for this question.

    I was wondering if someone could explain flash shadows to me, what causes them (specifically) and how to avoid them. I have three books and none of them make any mention of flash shadows.

    Thank you in advance.
     
  2. blansky

    blansky Subscriber

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    Could you give more information on what you are asking about. A flash is a sharp pinpoint light source ( generally) unless modified by a softbox, umbrella, etc.

    It has a "hard" quality of light. Much like the sun. Therefore like the sun you get harsh shadows. A modified flash/strobe ( one that is softened by softbox/umbrella etc) is much like an overcast day. The sun has not changed it is just diffused by the clouds, hence soft quality of light and soft shadows.

    The placement of where the flash is in relationship to the subject will obviously determine how and where the shadows will appear.

    I'm not sure if this is what you're looking for but if you were more specific we could answer better.


    Michael MCBlane
     
  3. anyte

    anyte Member

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    I was taking test shots, to see what kind of results I would get with different settings and with the flash. I wish I could post an example but I'm without a scanner for the next week or two. One of the shots I took was of my son standing on the back of the sofa. All the walls are white. The wall behind my son was 9 feet away from his position. It was a clear day with a lot of light coming through the double doors going out to the balcony. I had thought that with the flash I could reduce the shadows on the side of him that was away from the windows - which it did, but there's also a huge unnatural looking shadow behind him which could only be created by the flash. The shadow certainly wasn't there when I took the photo.

    I've seen "flash shadows" in other photos, typically on forums with people still learning (like myself).

    My first assumption is that I shouldn't have used a flash at all and that if I need additional lighting I should use another method.

    I hope that clarifies what I'm asking.
     
  4. glbeas

    glbeas Member

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    In this case knowing the flash would make a big ugly shadow there I would have found a large reflector and bounced the flash off of it to make the edges of the shadow fade to nothing yet still get a good fill. You would have to try differing aperture/ shutter speed combinations to get the desired balance between flash and ambient light.
     
  5. blansky

    blansky Subscriber

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    Anyte,

    What you are describing is a difficult problem for beginners using on camera flash. Strobe lighting typically used by pros and more advanced amateurs typically have "modelling light" built in. These are incandescent bulbs that are on all the time and let the photographer see where the light is going. We also don't use the hard flash/strobe of a on camera flash because as I described before you get very harsh light and harsh shadows.

    As was previously mentioned by glbeas you can use a reflector card/or sheet of some sort, to bounce the flash off of or bounce the flash off the ceiling (which I don't really like because of the angle of the light).

    What I would suggest is to try available light. You will need a tripod and will have a fairly slow shutter speed. Faster film will help. Buy a piece of fomecore, white card, or a sheet, and use this to bounce some of the window light back onto the shadow side of the subjects face. Then the light you see is the light you get.

    What you were attempting is a pretty difficult thing to achieve. You were attempting to have a flash fill to even out the available light and doing this with a camera strobe is not easy. What happened is your flash was way brighter than the available light and overpowered it and in the process produced the harsh shadow on the background. One thing that you could do it to take the flash off the camera, and have it a few feet to either side of the subject and above them a little so the shadow will fall lower behind their body and not right behind their head.

    Hope this helps.


    Michael
     
  6. Donald Miller

    Donald Miller Member

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    The flash shadows that you question are a matter of lighting ratios. If, for instance, you metered the "lit" flash output of a "split" lighting arrangement for proper exposure with a given film/camera/lens combination and then metered the proper exposure of the unlit portion of the persons face you would find that the lighting ratio would most probably exceed the exposure scale of any film available today. The answer to this problem is to provide fill lighting to those unlit areas. This can be accomplished by providing supplemental lighting through the use of additional strobes or by the use of reflectors to utilize the existing light in more suitable ratios.

    The laws of sensitometry are incapable of being compromised. The film and printing paper will only hold so much exposure scale (contrast).
     
  7. L Gebhardt

    L Gebhardt Subscriber

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    If you turned the camera on its' side then the flash was moved from above the lens to its side. When the flash is above the lens the shadows tend to fall below the subject and are not visible on the film. Once you flip the camera the flas is off to the side and the shadow is visible on the other side of the subject. If you have an external flash you can use a flip bracket which lets you move the flash above the lens in either configuration.
     
  8. anyte

    anyte Member

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    Thank you for all the great advice and information.