Underexposing skies

OK, I think I understand how to do this, but I want to make sure that what I am thinking is really what I should be
I want to take shots outside, and I want the sky to be underexposed.
I get a exposure reading for the sky, say f16 1/125
adjust flash to expose the subject properly
then change the shutter speed to say 1/250
that should underexpose the sky by one stop, am I correct

Still very new to flash photography, so any help would be appreciated, but my understanding is aperture changes subject, shutter changes background

I hope I am starting to understand this.

Thanks, Dave

Yes, it will be one stop below your inital reading. I hope your flash and body can sync at 1/250.

Ya, not sure. I think it is 1/200 actually. But the theaory of what I was saying was right, right?

Here is a link to one of jacobthephotographers videos that does what I am thinking
http://youtube.com/wat​ch?v=tQKqj4W0QWI

I think I am allowed to post a link, if not please remove..
Thanks again Dave

bmynbr wrote in post #5544540
But the theaory of what I was saying was right, right?

Yes

cool, thanks.
I guess I just need to get out and practice. And with this lovely lower mainland weather, I should be able to do lots this weekend.
Dave

bmynbr wrote in post #5544502
I get a exposure reading for the sky, say f16 1/125
adjust flash to expose the subject properly
then change the shutter speed to say 1/250
that should underexpose the sky by one stop, am I correct

I am little confused with what you are saying.
sky exp = f16 1/125 (what you get)
Now you set flash to subject exp f16 and 1/250? is that what you mean? if this is, I think this should work.

Ghosh,

You set your flash for proper exposure at f/16. The shutter speed won't affect the flash exposure. So you can change the ambient exposure by changing the shutter speed. In this case the OP can reduce the ambient exposure by 1 stop, by doubling the shutter speed.

If you are using a flash with TTL capabilities would you need to adjust the flash setting at all? Wouldn't you be able to meter off the sky to get the proper exposure of that, then point at your subject and fire away?

Polekat wrote in post #5547944
If you are using a flash with TTL capabilities would you need to adjust the flash setting at all? Wouldn't you be able to meter off the sky to get the proper exposure of that, then point at your subject and fire away?

Theoretically, yes. But some tweaking of FEC may still be required, depending on certain factors like subject luminance (light or dark clothing).