Noob Lighting question

Either I am way too tired or just missing it...
When you shoot people....well anything you want lights on....How do you know how to set your lights 1 or 2 stops less than ambient?
Do I need to meter the subject, then meter with flash?

Like using my 430 ex or AB800.....they have 1/4, 1/2 settings etc....which one is a stop or 2 less than my ambient....?

You can either use the guide number to calculate what kind of power you'll need or use a light meter. When you put a modifier on the flash it kind of messed up the guide number though. Some people, through experience, simply set the flash to a certain power, take a few pics, chimp, then adjust the power.

The 1/4, 1/2 settings on your flash are simply how much power the flash is outputting. For example if 430EXII is capable of outputting say 40 ws at ISO100 zoom 105mm at full power at 1/2 power it'll output 20 ws. It has nothing to do with 2 stops less than ambient.

I am assuming that you want your ambient about one or two stops under the exposure of the subject? Correct me if I'm wrong.

I don't do much outdoor strobist stuff (hate mosquito season) but I would suggest to meter for the ambient first, then set your camera two stops below that to dim down the background, and then very the power on your flash/strobe in order to get proper exposure on your subject.

camera meter to determine ambient. flash meter to determine flash power.

To measure the flash, you will need an incident meter. It will wait for your flash to go off and will give you a reading. I use a Sekonic L-358

billybookcase wrote in post #10486964
I am assuming that you want your ambient about one or two stops under the exposure of the subject? Correct me if I'm wrong.

I don't do much outdoor strobist stuff (hate mosquito season) but I would suggest to meter for the ambient first, then set your camera two stops below that to dim down the background, and then very the power on your flash/strobe in order to get proper exposure on your subject.

You've got what I am sayin......except the vary part...lol
I am just trying to see if there is a quicker way to "Know" how much to lower your or higher your flash settings should be.

"To measure the flash, you will need an incident meter. It will wait for your flash to go off and will give you a reading. I use a Sekonic L-358"
Admittedly, I have one and have not used it but 3 times. I think I got overwhelmed and just started to practice by "experience" only. I will pull it back out tonight and try it again.....I may PM you if it's ok?

Bill

Feel free...
I will check in tonight. Just keep practicing with it. You will get used to it.

Got all my stuff out last night,....but it was too late and not enough light...kept getting E.u. I will try again earlier today and practice.

If you get E.U. Try upping your ISO and or opening up your aperture.

poloman wrote in post #10492369
If you get E.U. Try upping your ISO and or opening up your aperture.

yeah...i did. I ran it up to iso 800 then 1000.....it was just too dark....oh..and had my 70-200 f4 on so f4 was the widest I could go.
Still not too sure how this works though.
If I am in day light and meter the scene and it says I need f8 @ 125th or whatever......how do I "know" what to set my flash on before I start shooting?

You first decide how you want the exposure of your background to be. So let's say you want to place it at f7.1 @125th. Now meter your subject area with the flash turned on and your light meter set to read the flash. (Middle box with lightning bolt in it) Pop the flash and see what you get. Work with the power until your get f8@125th. Your subject will now be 1/3 of a stop brighter than your background. Experiment with this stuff until you are happy (probably never but welcome to the club)

poloman wrote in post #10496620
You first decide how you want the exposure of your background to be. So let's say you want to place it at f7.1 @125th. Now meter your subject area with the flash turned on and your light meter set to read the flash. (Middle box with lightning bolt in it) Pop the flash and see what you get. Work with the power until your get f8@125th. Your subject will now be 1/3 of a stop brighter than your background. Experiment with this stuff until you are happy (probably never but welcome to the club)

thank you for your continued responses polo! I see what you mean now. i need to select what I want the shot to look like and then meter for it. So, it a nit shell...it's still a slight educated gamble with where to start your flash power at. You are right, I just need to practice with it more and get to the shoot about 30-45 minutes early and test it up myself!

No real guesswork. If you test the exposure of your background and then set your flash to handle a stop or less brighter, then set your camera to that setting, your background will be slightly underexposed and your subject will be exposed properly. It is trial and error setting the brightness of the flash but really doesn't take very long. It is important to set your camera to properly expose the flashed subject. In the example above your would set your camera to f8 @ 125th and an equivalent ISO.

poloman wrote in post #10500268
No real guesswork. If you test the exposure of your background and then set your flash to handle a stop or less brighter, then set your camera to that setting, your background will be slightly underexposed and your subject will be exposed properly. It is trial and error setting the brightness of the flash but really doesn't take very long. It is important to set your camera to properly expose the flashed subject. In the example above your would set your camera to f8 @ 125th and an equivalent ISO.

I thought i had it until i read this:
In the example above your would set your camera to f8 @ 125th and an equivalent ISO.
I metered the BG today @ 125th f10...liked it. I wanted the subject @ f11 or so.....I set my lights and metered them until I got the subject @ f11 with the light meter. My camera settings stayed at f10 though. Exposure turned out as nice as a practice shot could be......why would i set my camera to f11?

So that your subject would be properly exposed and your background would be underexposed by 1/3 of a stop. The reason your shot looks fine is that 1/3 of a stop isn't much. Go for a greater difference and check your results.