Flash gun

hobodan

hobodan

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Hi all, I have recently bought a YN-468ii flash for my 40D. I just trying to get to grips with the settings etc.
I mostly tend to shoot in Ap but even when the the flash gun is on & in TTL mode I still get ridiculously slow shutter speeds, when I switch to M mode & put the desired settings in myself my camera flashes the aperture in the top lcd display & the light meter is way off the scale.... Although the images seem correctly exposed judging by the view of the picture on the back screen!

The same thing happens with the pop up flash , the shutter speed increases a bit but no where near high enough to get a nice crisp shot indoors

I think what I'm asking is are you supposed to shoot in M mode & just ignore the camera's disapproval when using a flash?

Thanks in anticipation :D
 
The camera only meters for the available ambient light (ie, no flash) hence why the meter reading will look underexposed, the flash in TTL will make up for the exposure when fired.

I use a D90 which defaults to a min shutter speed of 1/60 in A mode, if you want a faster shutter you need to use manual mode.
 
Like terry said, your camera will have a particular shutter speed which it defaults to when you turn the flash on. For my D90 it is 1/60 for any of the semi auto modes. Some cameras allow you to change that setting, some don't. When you're in manual mode, the camera meter is looking at the ambient light. It might tell you that the picture is under exposed because it would be without flash. When you add the flash though, the camera uses the flash to light the foreground. Because you have two separate 'exposures' you can use that to your advantage. If there isn't much ambient light, then you don't need a flash shutter speed necessarily to make a crisp exposure. Also, you can underexpose the ambient a stop or more and isolate your subject. Or, you can expose for the ambient correctly and have a well balanced photo.

It is kinda amazing what a smart camera system is capable of in 0.0055 seconds.
 
In manual I presume you're choosing settings that don't let enough ambient light in for the camera to give you a meter reading (it only does +/- 2) but then the flash is picking up the slack and giving you the correct exposure. Put the camera in M mode and take a shot with the flash turned off, then turn the flash on and take the same shot again with all the same settings and you'll see how much the camera is capturing and how much the flash is illuminating.

casts_by_fly said:
Like terry said, your camera will have a particular shutter speed which it defaults to when you turn the flash on.
Click to expand...

I don't think any Canons do this.
The 40D acts exactly the same as with no flash attached except it won't pick a shutter speed higher than the max sync speed of the camera (1/250) or it can be fixed at 1/250 in Av with a custom function (but what's the point of Av mode if you're fixing the shutter speed, might as well use M). Turning the flash on doesn't affect anything unless you change that custom function
In P mode it will only pick a shutter speed between 1/250 and 1/60 with a flash attached but in Tv and Av you can have anything between 1/250 and 30 seconds and in M you can have anything between 1/250 and bulb.
 
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Thanks people, much appreciated.
I think like you say I'll just have to experiment & try different exposures.

I've always struggled to get clean images indoors without flash, even at iso 800 with my 50mm 1.8!
My low energy lightbulbs may have something to do with that though :D
 
I have just brought the same model flashgun to use with my Nikon D40 and was going to ask the same questions. Thankyou to everyone which has given you advice as it has now also helped me in understanding in what I have to do. Thankyou .
 
Hi Budgie,

Just remember with the D40 you can go up to a 1/500 shutter speed and still synch. One of the nicer features of the D40.

Thanks,
Rick
 
hobodan said:
Hi all, I have recently bought a YN-468ii flash for my 40D. I just trying to get to grips with the settings etc.
I mostly tend to shoot in Ap but even when the the flash gun is on & in TTL mode I still get ridiculously slow shutter speeds, when I switch to M mode & put the desired settings in myself my camera flashes the aperture in the top lcd display & the light meter is way off the scale.... Although the images seem correctly exposed judging by the view of the picture on the back screen!

The same thing happens with the pop up flash , the shutter speed increases a bit but no where near high enough to get a nice crisp shot indoors

I think what I'm asking is are you supposed to shoot in M mode & just ignore the camera's disapproval when using a flash?

Thanks in anticipation :D
Click to expand...

Go into the custom menu settings and fix the shutter speed when using the flash at 1/250. It's there in the menu. I don't have my manual to hand to know which option it is, but it is there. Set that and you'll be fine.


(Rick, 40D and D40 are two very different cameras - one's an entry level Nikon, one's a prosumer Canon)
 
I definitely prefer manual settings when using flash. A combination of auto exposure and auto flash will usually get things "sort of" right but it will also often NOT get the look you are after.
 
Like Alastair said, the default with flash in Av is for the meter to measure ambient exposure level and balance the shutter speed for that, with the flash exposure.

In the menu there are two other options - one will allow the shutter speed to track the ambient down to 1/60sec, but no further (it's the same as the default on P). There is another option, I think on the 40D, that will fix it at 1/250sec in Av.

I usually use the standard default option on Av, and vary exposure of the background with +/- compensation on the camera, and adjust the flash brighthness with +/- compensation on the flash. Or use manual.
 
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