40D Flash Puzzle

My son works with a professional photographer. When shooting a portrait indoors with flash he has been told to use aperture priority with an aperture of 11. When he does so the results aren’t good, due to the fact exposure times range from ½ to 2 seconds. The camera automatically compensates the flash to +2. The professional is using a pro Nikon camera.

Is there a reason why the pro Nikon camera works at this setting, but the 40D won’t.

The in built flash and speedlite work fine if camera set to portrait, auto or shutter speed priority.


Also, I am a little puzzled by the following

If camera shutter speed is set to 1/60 it selects an aperture of 5.6 and produces a perfect picture.
If the aperture is set at 5.6 it selects a shutter speed of 2 seconds, with the obvious poor results.

Any help or explanations would be very appreciated.

Ijon

You need to have the flash set up correctly. When shooting in AV mode set the flash to a fixed shutter speed of 1/250 and dial your aperture setting to the DOF you want to achieve.

That is the short version. Read the link below for the longer version.

http://photonotes.org/​articles/eos-flash/

The easy way, as it appears you are new, is to use P mode and take some more time to learn how to use flash in the other modes.

I'm not sure how aperture priority works on Nikon cameras, but on Canons, when set to Av the camera assumes you're using the flash as fill and sets the exposure for ambient light.

Your son should be shooting Manual with flash. He can set the aperture to whatever is desired for depth-of-field, and adjust shutter speed to allow more or less ambient light (slower shutter speed to allow more ambient; faster to allow less, not to exceed 1/250th unless he's also set high speed synch). The flash will meter for a "proper" exposure if set to ETTL.

Not sure what you mean by "the camera automatically compensates the flash to +2", but he may have some Flash Exposure Compensation dialed in, which is adjustable in-camera.

Brett is absolutely correct.

That and those settings are pretty awful anyway for indoor photography in general.

yes, the best exposure mode with canon flash is M mode - the flash will still be in "auto" as it puts out enough light to properly expose

When shooting with flash indoors the camera must always be set to manual mode..

Select a shutter speed around 125th to 160th..

Thank to everybody for the help and advice. I‘ve learned a lot. We’re now getting good results shooting in manual.

"he has been told to use aperture priority with an aperture of 11" - a 'professional' told him this?

Enough said...

Bannor

Bannor wrote in post #9885595
"he has been told to use aperture priority with an aperture of 11" - a 'professional' told him this?

Enough said...

Bannor

The pro was thinking about job security

Bannor wrote in post #9885595
"he has been told to use aperture priority with an aperture of 11" - a 'professional' told him this?

Enough said...

Bannor

Nikonians

Bannor wrote in post #9885595
"he has been told to use aperture priority with an aperture of 11" - a 'professional' told him this?

Enough said...

Bannor

Canon has a custom function that allows you to have the shutter speed default to the synch speed of the camera when you turn on the flash. It stops metering for ambient and thus kills Av as a fill flash mode.

This is not the Canon default, you have to set it in the menu. With Nikon, this is the default operation.

So the 'professionals' instructions were correct for a Nikon. He was probably just ignorant that Canons work differently.

JeffreyG wrote in post #9885836
So the 'professionals' instructions were correct for a Nikon. He was probably just ignorant that Canons work differently.

F/11? Maybe if he's using an AC strobe, but not a hotshoe flash

While there is certainly nothing written in stone about not using small apertures for portraits, conventional wisdom indicates that in general, the LARGER the aperture, the more interesting the picture appears to be. Something to do with the background not being very important in portraits, so it is blurred out by setting a large aperture (see also 'bokeh'). AKA 'separating subject & background' - a common and well-known method of doing portraits, with or without flash. This is covered in elementary photography skills - nothing to do with Canon / Nikon. Even I am aware of this - so why is this alleged 'professional' not?

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timbop wrote in post #9886086
F/11? Maybe if he's using an AC strobe, but not a hotshoe flash

This is f/11 and ISO160 using just two 430EX flashes. One flash lit the subjects and one lit the background. I really had to use f/11 here as the DOF is barely adequate. I have a 20x30 print of this hanging on a wall and the little girl on the right is barely within the DOF.

I also admit - a third flash or reflector to light the shadows would have been good, but this was kind of spur of the moment. But the 430EXs had enough power at f/11.

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Just a clarification of the type of photo work carried out. It involves visiting local council/government establishments photographing people and their surroundings for use in local newspapers and newsletters. A good DOF is probably a requirement.