I may have a problem with my camera, maybe this is normal!

Discussion in 'Photography Beginners' Forum' started by Sonoma, Sep 3, 2010.

  1. Sonoma

    Sonoma No longer a newbie, moving up!

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    While experimenting with the new flash today I noticed that I get different results in different modes. By this I mean, in Manual Mode, with the flash turned on, I have to adjust the SS to 1/4 and aperture to f4.5 to get the meter set about right, but the picture is out of focus. When I change to P(program) mode the results are quite different. With the flash turned off the SS is 1/4 and the aperture is f4.5 and the picture is out of focus, but as soon as I turn on the flash with the camera still on and in P(program) mode it changes to 1/60 for the SS at f4.5, and of course the picture comes out fine.

    Throughout this test the camera was at ISO 400 and about two feet from the subject with the flash at about 75 deg. The camera is a Canon Rebel XT and the flash is the Vivitar DF-383-CAN(ETTL capable).

    I hope this make sense. I was trying to use the camera in Manual Mode only just for the experience.

    Thanks
    Gary
     
  2. Village Idiot

    Village Idiot No longer a newbie, moving up!

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    The in camera meter never meters for the flash. The flash meters for the flash.
     
  3. TiCoyote

    TiCoyote TPF Noob!

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    The SS and aperture have no affect on focus, and numerous combinations will work. If your SS is 1/4, and you're not using a tripod, you may be experiencing camera shake, or you may just be seeing movement in the image.
     
  4. edouble

    edouble TPF Noob!

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    The program modes are "quick" settings you can program to use for specific situations. You have to manually change the aperature/shutter speed. Different model cameras may be perform differently than what I just explained but this is the general purpose of program mode. I would not recommend using program mode to experiment with flash until you have a better understanding of how aperture and ss influence ambient light and flash.

    A better "experiment" mode is aperture or shutter mode. "Mostly" f8 with a 1/200 exposure is a good starting point. Take a photo at these settings without flash. Adjust aperture until ambient light is to your liking. Turn your flash on and adjust flash output. If using ttl metering than I suppose your camera would handle everything.

    In program mode is your auto focus turned off?


    I am learning flash as well. Hopefully people with more experience than me will chime in.
     
  5. tirediron

    tirediron Watch the Birdy! Staff Member Supporting Member

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    Not quite true; aperture has a major impact on focus through depth of field.

    All very true and excellent points.
     
  6. Sonoma

    Sonoma No longer a newbie, moving up!

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    Never mind, I just tried it in Manual Mode at 1/125 sec at f4.5 with everything else the same and it came out pretty good. When using flash you still use the exposure meter built into the camera, correct?

    God help me, I have got so much to learn!

    Thanks for the help
    Gary
     
  7. Village Idiot

    Village Idiot No longer a newbie, moving up!

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    Not in the same way. The in camera meter still meters the scene like before. It doesn't not take into account that there is a flash on your camera.

    A photo taking using flash is essentially 2 exposures, an exposure created by ambient light and an exposure created by the flash. Ambient is controlled essentially by aperture, shutter speed and iso. The flash is controlled by iso and aperture.

    That is the most simplest way of looking at it without going into how shutter speed can affect the exposure and other variables.

    So say you want to cut out the ambient as much as possible, you would shoot at your highest shutte speed and the flash would expose normally unless otherwise set by yourself to over expose or under expose.

    If you wanted a scene mixing ambient and flash, you would use your meter to expose the scene properly with the camera, and the flash would fire and expose the scene just the same. You have to watch for light colors here, as the color temp of your flash is usually about 5600K and if you're shooting under a normal incandescent light, it'll be much warmer, giving an orange color mixed with the white from the flash exposure.

    Read this:
    Strobist: Lighting 101
     
  8. Sonoma

    Sonoma No longer a newbie, moving up!

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    Village Idiot, I hate calling you that because you certainly are not, thank you! Your explanation of this being two exposures makes good sense, and I will read the link you provided right after I get the yard work done. Don't want to lose any privileges here you know.

    Thanks again!
    Gary
     

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