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  1. #1
    Edimilson's Avatar
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    Problems bouncing flash off wall

    Hello!

    I have another newbie question for you guys.

    I've just bought a Vivitar 2800 form my old film cameras. I'm trying to learn how to best use it. I soon had sucess bouncing the light off my living room ceiling. Then I tried bouncing the flash off a wall. A voice in my head told me it was not going to work. It in fact didn't but I just can't understand why.

    I mounted the flash on my Olympus OM 2000 hot shoe. This flash model has a moving head. The head does not swivel, though I can set it at 90º, 75º, 60º and 0 degrees. Since the head doesn't swivel, I tried directing the flash at different angles towards the wall by holding the camera sideways (hope you can understand me now; English is not my native language). The problem is: I tried every aperture from 5.6 to 1.4 on the 50mm lens I was using. The negatives were all severely underexposed. The one shot at 5.6 was simply blank. The negatives shot with the flash pointing to the ceiling, on the other hand, looked quite all right. This is a mistery to me. I have tried both automatic and manual operation of the flash, to no avail.

    Perhaps it has to do with the so-called thrystor. It's for some reason quenching the flash sooner than it should because the flash is not upright. I don't see why that should happen, though. Any ideas?

    Thanks a lot!
    Edimilson

  2. #2

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    Good Afternoon, Edimilson,

    What is the distance from the flash to the wall? What color is the wall? What color is the ceiling? How high is the ceiling? Are the surfaces highly reflective or relatively dull? All these factors will have an effect on how much light bounces. In general, a small, portable flash such as the 2800 will probably be marginal for bounce use. Even in Manual mode, it just doesn't have enough output to be very effective, unless the reflective surface is white and fairly close. Count on losing at least two or three stops in bounce mode compared to direct flash.

    Konical

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    Bom dia, Edimilson,

    Sorry, Portugese is not my language, but I am learning.
    The main reason why you get under-exposed negatives is the distance between your flash and the bouncing surface.
    The ceiling is closer to it than the wall.
    The more a bouncing surface is removed the more the flash is spread, giving you less light-concentration on one spot.

    Try to bounce off a white card board next to you and you will, with some experimenting, get a good result.

    Greetings,
    Peter, Goiânia, GO

  4. #4
    Edimilson's Avatar
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    I am always amazed at how nice you guys are.

    Well, I calculated 5 meters from the camera to the ceiling and from there to the sofa (which was then my subject). The pictures were well exposed.

    When I tried boucing the flash off the wall, the distance from the camera to the wall was about 0.5 meter and from the wall to my nephew another meter. The pictures were all underexposed.

    I am pretty sure I followed the same reasoning as before when I turned the flash towards the wall. I just thought that something goes wrong when you don't use the flash upright on the hot shoe. If it's not that, then maybe I just missed my nephew because he and the flash were not at the right angles. I mean, perhaps the light just didn't hit him. I just don't know. I'll look into that.

    Thanks anyway! You're great.

    Edimilson

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    Edimilson's Avatar
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    One more thing: as to the color of the wall and of the ceiling, they are the same, almost white.

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    We are nice here, we respect each other and try to help each other !

    Quote: [when you don't use the flash upright on the hot shoe] it is still connected with the hot-shoe is it ?!
    Try it with an empty camera and see if the flash fires.

    Peter

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    Edimilson's Avatar
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    Hi Peter,

    Yes, I am sure the flash fires. I took pictures of my nephew then and he too saw it fire each time. I will try increasing the distance between me and the wall so that the light will spread more. If you don't see any reason why the flash shouldn't work when not upright, perhaps the bounced light was just not hitting the boy right.

    According to that dial on the back of the unit, I should have used f 16 on the camera for that distance, which was around 2 meters (a little more than 6 feet). I tried all apertures from f 16 to f 5.6. This last aperture resulted in less in a better negative. The negative corresponding to the shot done at f 16 was simply blank.

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    hi edimilson

    sounds like your flash isn't giving off enough light to
    bounce off the wall and illuminate your subject.
    i am guessing that the sync speed ( x ) for camera is 60thS.
    just to have a little fun, and play a little bit,
    what i would do is put the flash on manual, and full power.
    but instead of shooting at 60th, bracket your shutter speeds and "drag" your shutter.
    the first burst do at 6oth, then 30th then 15th then 8th ...
    and you should hopefully be able to see your subject getting in the light ...
    another thing you could do, is instead of being so far from the wall or ceiling, and then
    from the wal / ceiling to your subject,
    get a white card - like foam core or matboard and make believe IT is the wall or ceiling
    and bounce the flash off of IT, and have the board closer to the camera and your subject.
    it will soften the light and bounce the light (hopefully )
    at the end of your experiment you will be able to see better what you need to do
    in the way of shutter speed, light and bounce distances. don't forget you need
    a TON of light to bounce ( as konical said ).

    good luck and have fun!

    john

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    Edimilson's Avatar
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    Nice! Thanks. I'll try that tomorrow too.

  10. #10
    Lee L's Avatar
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    Here's the manual for the 2800 in case you didn't get one with the flash. http://www.mattdentonphoto.com/cameras/vivitar_2800.pdf

    However, their instructions for measuring from the flash to the bounce surface to the subject, and making sure that distance is within the range you have set on automatic mode, are overly optimistic. I'd say to be sure not to be greater than 1/4 to 1/2 the maximum distance for whatever automatic range you're using when measuring the distance from flash to reflector to subject, even with white walls. Walls tend to bounce the flash everywhere, nice for diffusion, but very costly in terms of the amount of light reaching your subject.

    Also, if you're square to the wall when bouncing the flash, make sure that the flash hits the wall no more than half way to your subject. If you aim the flash too far along the wall (or ceiling), the reflected light will fall mostly behind your subject.

    Read about the auto-check indicator on the 2800 in the instructions. It allows you to check on whether the subject is getting enough light, either after an actual exposure, or with a test flash button. It will work both straight ahead or with bounce.

    Use the videos here http://www.abetterbouncecard.com/ to show you how to make your own bounce card for use on the flash to achieve softer light.

    Lee

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