Help using a flash (most basic question)

tomkbucks

tomkbucks

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ok this sounds the most basic of questions so i do apologise, i never have used a flash before as everything i do is either outside or well lit. Ive just bought a basic YN468 to use on my 60d which is TTL, im finding that when i put it on set the camera to AV its still metered as if there was no flash attached and giving me a very slow shutter speed. The flash does fire but its as if the camera is not understanding its there ? what am i doing wrong or do i have to go full manual here ?
 
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Can you post a little more info regarding your camera/flash set up

If it is a well lit scene it may need very little flash power so you will not notice it.

Try under exposing the shot and then fire the flash.
 
no probs , camear is 60d, in a normal lit room an office at the moment , set the AV to 5.6 on the camear and its giving me a 0.3" exposure time with the flash on or off, the flash is set to ettl if i take the image not only is it a little wobberly its far to over exposed
 
Does the 60d let you fire a pre flash to determine the flash strength?

try making the shutter speed 1/125th and see what happens as the shutter speed controls the ambient light.

Post some examples with exif intact please.
 
thanks , how do i fire a pre flash ? i dont have a way to get the images up till i get home but in M @ 125 and F5.6 its all far to dark which does not make sense...
 
tomkbucks said:
thanks , how do i fire a pre flash ? i dont have a way to get the images up till i get home but in M @ 125 and F5.6 its all far to dark which does not make sense...
Click to expand...

Not sure you have your settings correct. Are you sure you are in ttl mode?
 
ok from the flash control screen for the external flash its set to ' E-TTL, 1st Curtain FEB and EXP is set to 0 and ettl II meter is evaluative, zoom is auto, The LCD on the back of the flash shows the F number , the AF seems to flash on the flash too, just odd its not feeding back to the camear to change the shutter speed?
 
Canon cameras will hold onto the correct exposure settings in the semi auto modes with a flash on. So in AV it'll be low shutter speeds.
I think in P the camera sets a higher shutter speed with a flash attached, never used it though.

I usually pick a manual setting of 1/100 and f5.6, set the ISO to have the background 1-2 stops underexposed and bounce the flash, then use FEC to taste. Btw the ETTL meters slightly more consistently if you use the custom function to set it to average rather than eval.
 
ah thats interesting did not know that , i will test that tonight and post my results ! thanks Phil V
 
Ok I'm getting somewhere , while in p mode the camera / flash do indeed now seem to be working in harmony but... With the flash on (in P) I'm unable to have a choice over the aperture ( which I do have the choice when the flash is off )
 
I think the issue here is the flash has no idea how much power to apply as you would need to apply a pre-flash. The flash is just using the ETTL through the camera and basically you supply a fill flash. (the aperture value is causing the shutter speed to drop.)

Manual mode will resolve this as you can enter you own values and the flash should power up or down based on your settings.

Tips to remember...

The Shutter controls the ambient light around the subject not the flash power.
Aperture controls the Flash power...f22 would need more power than f2
Flash gun to subject is also very important as power from the flash would need to be increased or decreased (more when flash is off the camera)

Play around with the shutter (keep this to around a level you can hand hold it to if you want more ambient light in the shot) and Aperture.

Post a few examples you are getting with your camera settings...

Dan
 
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Check handbook. The default on Canon Av is for the shutter speed to match ambient, hence the long exposure. You can change that so it will only drop to 1/60sec (same as P) or to switch to a fixed 1/200sec. In custom functions.
 
ah see RTFM... did not think of custom functions ! i think the full manual is the way to go here so id best find a willing subject and do a bit of tinkering ! thanks for your help guys i must admit ive only used it in the past to 'bounce' light off the ceiling but do have to shoot a few things for my office next week (which is quite dark ) i like a shutter of 1/100 min when i shoot /people and just need to to tinker,
 
tomkbucks said:
ah see RTFM... did not think of custom functions ! i think the full manual is the way to go here so id best find a willing subject and do a bit of tinkering ! thanks for your help guys i must admit ive only used it in the past to 'bounce' light off the ceiling but do have to shoot a few things for my office next week (which is quite dark ) i like a shutter of 1/100 min when i shoot /people and just need to to tinker,
Click to expand...

Yes basically RTFM :D

If people are sitting/standing still, you can usually get away with 1/60sec or even 1/30sec and that will make the most of whatever ambient light is about, as will pushing the ISO of course.

When bouncing in a small room, you don't have to worry so much about ambient light as the bounced flash will pretty much fill the whole area, but in larger rooms the background will usually go dark without dropping the shutter speed. Then there is the issue of also balancing the colour of the flash with ambient (gel). Every situation is different.
 
yup and this is were im very much out of my depth! im awful with learning from books , id love to go on a training day to be 'shown' as thats how i end up learning , if i could get an hours of someones time that knows this stuf to show me it would be great !
 
You might want to also consider using Second Curtain sync if you plan to shoot s moving subject, second curtain you would still get the subject clear with blur from behnid the subject not in front...(just a thought).

You also need to remember shooting around 1/125 normally kills the ambient light if you shooting directly at the subject (depending of the size of room or colour of walls).

Might be worth checking out a Guy called Bryan Peterson I found his explanation to using flash very clear and useful.

Dan.
 
Danzaroonie said:
You might want to also consider using Second Curtain sync if you plan to shoot s moving subject, second curtain you would still get the subject clear with blur from behnid the subject not in front...(just a thought).

You also need to remember shooting around 1/125 normally kills the ambient light if you shooting directly at the subject (depending of the size of room or colour of walls).

Might be worth checking out a Guy called Bryan Peterson I found his explanation to using flash very clear and useful.

Dan.
Click to expand...

A little known fact about second-curtain sync is that with both Canon and Nikon it is not even enabled until you get down to about 1/30sec (where it is more like middle-curtain sync, if you follow) and has almost no visible effect until quite a bit longer than that.
 
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