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Thread: Is my flash underpowered?

  1. #1

    Default Is my flash underpowered?

    I have a 580EX flash currently. I noticed that whenever I shoot indoors, my shutter spd will fall to about 1/20s @ f/2.8 @ ISO 400. When I use flash, it raises to only about 1/60s @ same f/no same ISO. I tilt my flash head right up as I am using an in-built bounce card on the 580EX. I have to use f/2.8 ISO 1600 to hit 1/200s. I was wondering if I can hit 1/200s w/o ISO 1600 due to the noise problem. Is my flash underpowered? I bought this from a fellow CS-er few months back and he claims it to be new. Thanks man...

  2. #2
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    Default Re: Is my flash underpowered?

    How far is the subject from the camera? When you are using bounce, the power from the flash drops tremendously. Does the flash work normally when you are using direct flash? For my experience, the flash is capable to provide perfect exposure at 1/200s at iso 100 when the room is completely dark.

  3. #3

    Default Re: Is my flash underpowered?

    Which shooting mode (P, Tv, Av, M or...) are you using?
    • In P mode
      • If the scene is bright enough, fill-in flash mode is activated to reduce shadows. So the shutter speed and aperture is determined by the camera.
      • If the scene is dark, shutter speed is set at 1/60 s, and camera exposes for the foreground subject. Ambiance light is not taken into the exposure.
    • In Tv/Av mode
      • You set the shutter speed/aperture, and the camera will try to expose for the entire scene, taking into account ambiance light. That's why if you set Av at f/2.8 and it's dark, the shutter speed drops to expose properly the background as well. Flash is used to properly expose the subject.
    • In M mode
      • You set both the shutter speed and aperture, and the camera will meter for ambiance light as well so that the scene is exposed properly. Works similar to Tv/Av mode. Flash is used to properly expose the subject.
    • In any of the PIC modes
      • Camera works like P mode most of the time.
    Edit: The above is how Canon cameras work. Not too sure how other brands work.
    Last edited by Ah Pao; 4th June 2007 at 08:50 PM.

  4. #4

    Default Re: Is my flash underpowered?

    The 580EX has a GN of 58, right? I use Olympus FL-50 which has a GN50 "only", but I never HAVE to use such low shutter speed or wide aperture or high ISO. I suggest you read the manual (camera and flash) or check out the flash or the camera. In my opinion it should not be difficult to use better, more reasonable values. I can use 1/4000s, f2.0, ISO 100 and still light up a whole room up to about 10 meters.

  5. #5

    Default Re: Is my flash underpowered?

    Quote Originally Posted by artofshuenalogy View Post
    I have a 580EX flash currently. I noticed that whenever I shoot indoors, my shutter spd will fall to about 1/20s @ f/2.8 @ ISO 400. When I use flash, it raises to only about 1/60s @ same f/no same ISO. I tilt my flash head right up as I am using an in-built bounce card on the 580EX. I have to use f/2.8 ISO 1600 to hit 1/200s. I was wondering if I can hit 1/200s w/o ISO 1600 due to the noise problem. Is my flash underpowered? I bought this from a fellow CS-er few months back and he claims it to be new. Thanks man...
    does not seem anything wrong with the flash from what i read.

    I believe you do not know how to use it. you need to go back to your basic.

    and read your manual. It helps.

  6. #6

    Default Re: Is my flash underpowered?

    you want power? point the flash straight direct at the person, set 1/60 at whatever aperture below f/8 and ISO 800.

    if you're not on tele range, you'll get your subject lighted, no matter what.

  7. #7

    Default Re: Is my flash underpowered?

    Quote Originally Posted by Stratix View Post
    you want power? point the flash straight direct at the person, set 1/60 at whatever aperture below f/8 and ISO 800.

    if you're not on tele range, you'll get your subject lighted, no matter what.
    I would say with a flash GN58 you will only get a white, overexposed spot on the place where the person was unless the distance is like 50-100 meters. What is the point in ISO800 in combination with a powerful flash direct in face?

    Not a very helpful advice to a newbie. I don't want to use stronger words, but if that is all you can contribute with it is better to keep quiet. Anyway, if it meant seriously than ISO 1600 is even better, isn't it? Remember, he/she has already tryed ISO 1600, f2.8 and that should definitely blow out anybodies face, even if indirect flash is used. Regardless how experienced and knowledgable you are, eigther you don't really know what you are talking about or forgot that you also have been a newbie once and just trying to be funny.

    For 99% of the time, indoor shots never need to be taken with anything more than ISO 100, especially if so slow shutter speed is used, but if range is not enough it is better to reduce f-number to increase aperture so that more light is let in the camera. Increasing ISO is a last resort since it always reduces detail and introduces noise, regardless of camera. It is just like film, the lower ISO (ASA) the more detail in the final image.

  8. #8
    Senior Member wrx_sti_22b's Avatar
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    Default Re: Is my flash underpowered?

    Quote Originally Posted by Ah Pao View Post
    Which shooting mode (P, Tv, Av, M or...) are you using?
    • In P mode
      • If the scene is bright enough, fill-in flash mode is activated to reduce shadows. So the shutter speed and aperture is determined by the camera.
      • If the scene is dark, shutter speed is set at 1/60 s, and camera exposes for the foreground subject. Ambiance light is not taken into the exposure.
    • In Tv/Av mode
      • You set the shutter speed/aperture, and the camera will try to expose for the entire scene, taking into account ambiance light. That's why if you set Av at f/2.8 and it's dark, the shutter speed drops to expose properly the background as well. Flash is used to properly expose the subject.
    • In M mode
      • You set both the shutter speed and aperture, and the camera will meter for ambiance light as well so that the scene is exposed properly. Works similar to Tv/Av mode. Flash is used to properly expose the subject.
    • In any of the PIC modes
      • Camera works like P mode most of the time.
    Edit: The above is how Canon cameras work. Not too sure how other brands work.
    Sounds similiar to my Olympus...

  9. #9
    Moderator catchlights's Avatar
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    Default Re: Is my flash underpowered?

    Quote Originally Posted by artofshuenalogy View Post
    I have a 580EX flash currently. I noticed that whenever I shoot indoors, my shutter spd will fall to about 1/20s @ f/2.8 @ ISO 400. When I use flash, it raises to only about 1/60s @ same f/no same ISO. I tilt my flash head right up as I am using an in-built bounce card on the 580EX. I have to use f/2.8 ISO 1600 to hit 1/200s. I was wondering if I can hit 1/200s w/o ISO 1600 due to the noise problem. Is my flash underpowered? I bought this from a fellow CS-er few months back and he claims it to be new. Thanks man...
    why you need to shoot at 1/200s with flash? what type of effect you want to achieve?
    Shoot to Live, Live to Shoot
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    Default Re: Is my flash underpowered?

    what mode on the flash are you using to begin with. ?
    if the 580ex is not powerful enough for you, there is nothing on the canon range more powerful than that.

  11. #11
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    Default Re: Is my flash underpowered?

    Your flash is working fine. There is only so much a flash can illuminate an indoor area(especially a large room or hall) without overexposing the foreground or your subject while still maintaining a good balance exposure between the foreground and background. What your camera has done is to maintain some of the ambient light to give you a more natural lighting.

    Your flash is not going to be a wonder tool that will automatically light up all areas of an indoor space. Light travel in a straight line, and the power will gradually decrease with distance, so those nearest to the light source will be the brightest. Unless you don't mind a dark background, then you can easily switch to manual mode, select 1/200s and any aperture, I'm sure your flash will light up your subject just fine.

    If you want all area to be bright, while maintaining a fast shutter speed, small aperture, low ISO, then you'll need several flashes to cover all these areas. One flash is not enough.
    Canon 80D|Panasonic LX3/LX5
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  12. #12

    Default Re: Is my flash underpowered?

    Perhaps your camera was trying to expose for the background (which your flash may not be able to light up) that is why your shutter speeds are very slow.

    Another reason could be that the PCB of your flash is kaput. It fires, but doesn't sync properly. As good as no flash. If you have an offshoe cord, mount the flash on the offshoe cord and take a picture of the flash. If the flash fires but your photo doesn't seem to show it, then more or less means a kaput PCB. Happened to my 420EX. Can be fixed for a fee @ CSC.

    One reason I can think of to shoot at high shutter speeds while using flash is to kill off the background. Once aperture is set, shutter speed can be cranked up (up to the maximum flash power duration before you start loosing flash power as well) to control ambient light. Helpful if shooting in sunlight and you want the puny flash to overpower the sun.

    Another reason I can think of is to shoot fast moving objects. I'm not sure if it is required since if the aperture is really small the camera won't capture the motion trail anyway but that's how i've been shooting my hamsters lately. This one shot @ 1/160s...

    Last edited by kongping; 5th June 2007 at 10:29 AM.

  13. #13
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    Default Re: Is my flash underpowered?

    Quote Originally Posted by kongping View Post
    Wow! How did you get your hamster to hang on one hand/paw like that? So cute!
    Canon 80D|Panasonic LX3/LX5
    35f2 IS|50f1.8|85f1.8|12-24f4|18-135f4-5.6 IS|28-75f2.8

  14. #14

    Default Re: Is my flash underpowered?

    Just one point to remember. For flash photography, the exposure is determined by the flash power, aperture and ISO only. The shutter speed is used only to balance the ambient light.

    The duration of the burst of flash is very short and can be anything from 1/500 to 1/20000 depending on the power of the flash. Since this is very much shorter than the duration of the shutter, you will not be able to get a motion trail if you have no ambient light to light the subject for the entire duration of the shutter opening.

  15. #15

    Default Re: Is my flash underpowered?

    Quote Originally Posted by catchlights View Post
    why you need to shoot at 1/200s with flash? what type of effect you want to achieve?
    There are many reasons to use shutter speeds even higher than 1/200s. I often use 1/500 or even higher in combination with my flash (Olympus FL-50). One reason is to kill motion blur, especially background motion. Another reason is for fill-in flash outdoors a sunny day. A third reason is for macro. The ability to sync at up to 1/4000s is a bless. Definitely freezing all flying insects and other movements blur caused by the wind. A fourth reason I can come up with is to freeze camera shake caused by the lens effect. Using a 150mm lens normally demands at least 1/300s shutter for best results. So, while the flash discharges very fast (typically at about or over 1/20000s) it can only freeze motion if the background is totally dark unless the shutter speed is also high.

  16. #16

    Default Re: Is my flash underpowered?

    Quote Originally Posted by kelccm View Post
    If you want all area to be bright, while maintaining a fast shutter speed, small aperture, low ISO, then you'll need several flashes to cover all these areas. One flash is not enough.
    That depends on the size of the room and the type of image you want to take. A flash with GN58 (or GN50 as mine) can light up a quite large room evenly by itself. But yes, if you put a person 1 meter in front of the camera and you have a large room behing the person you have to make a choise what is important to catch, or you have to use several flashes.

  17. #17

    Default Re: Is my flash underpowered?

    Quote Originally Posted by catchlights View Post
    why you need to shoot at 1/200s with flash? what type of effect you want to achieve?
    Eg if ur using 70-200mm lens and shooting at 200mm

  18. #18

    Default Re: Is my flash underpowered?

    Thanks for ur advices

  19. #19

    Default Re: Is my flash underpowered?

    Btw I have another question. How can I use flash and use shutter spds higher than 1/200s. My cam doesn't allow me to. Has it got to do with the sync settings? Thanks!

  20. #20
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    Default Re: Is my flash underpowered?

    Flash X-Sync speed is 1/200 (for 400D) and 1/250 (for 30D)..

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