so scared by the world of off camera flash..

So I have finally, baby stepped my way into off camera flash photography(firing my sigma ef super 500 into an umbrella via pc sync chord...

I had my first real shoot today...which should of been a test shoot. I'm so scared..I really don't know what Im doing. How far the flash/umbrella should be from the subject( I mainly shoot people), how high... the power, 1/4, 1/8 1/32...

I did get some reasonable pictures, but I guess I attribute that to having some basic knowledge and well luck...
I know most people will say, just practice and try different things...but for once, I would like to be text book good at something...
I feel flash is a concept based on math...
and well Im horrible at math and interpreting it through flash is even harder than I thought...
like if someone told me to do a basic butterfly lighting set up with one light, I know Id place the source just above my camera to the middle of the subject...but I don't know at what intensity or particular distance...
please god don't tell me I need a light meter, Im deathly afraid of those, and broke...

Im not sure what my question is, this might be a rant, but I guess I just really want to understand the rules of flash...

thanks for listening...

well, it sounds like a light meter would solve most of your problems.

sorry.

First time I used off camera flash, I cheated. I used ETTL, there, feel better

You've probably heard of it before, but when it starts like this how could it be not what you want:

http://strobist.blogsp​ot.com/2006/03/lightin​g-101.html

and.duncan wrote in post #5534778
You've probably heard of it before, but when it starts like this how could it be not what you want:

http://strobist.blogsp​ot.com/2006/03/lightin​g-101.html

perfect place to start, if this site doesn't get you excited about flash photography nothing will.

I would say to use e-ttl but you are using a PC sync cord so that is out of the question. Set your flash at 1/2 power to start (good mix of recycle time and power) then set your camera settings based on the amount of ambient light you want to let in andmove the flash closer or further based on what you see in your histogram. Remember, Aperture affects both ambient and flash but shutter speed only affects ambient light. Keep it at or undedr your max sync speed though.

Wireless ETTL makes life really easy, once you've got that sussed you can move on to manual. The Strobist will teach you how, it's pretty easy but could be overwhelming if you're new to it. The trick is balancing the flash and ambient for the effect you're trying to create.

You are using the flash on M.
*very* roughly: (without too much math): Attach the flash to the camera hotshoe.
This will avoid having to use a bit of math involving guide numbers

Set camera and flash to manual. Set power of the flash to full, zoom setting to 28mm (since that is what the flash will zoom to if off camera I think). Aperture and ISO to f/8 and 100.
The distance scale on the flash will give you a distance reading. Probably around 4 meters.

So. Since you are using an umbrella, you'll loose a bit of light. Say 1 1/2 stop.

What does this tell you?

• If you fire the flash on full power, trough an umbrella, and set the camera at ISO 100, f/8, a subject about (roughly) 2 meters from the umbrella will be well exposed.
  
  
• If you set ISO 200, or f/5.6; ISO 100, you can set the flash to 1/2 power for the same result: Each stop on the camera equals a stop in flash power.
  
  
• If your subject is half the distance to the flash, you need 1/4 of the power. (Inverse square law)
  

Nobody will get hurt from off camera flash, so there is no point in being afraid of it. Give yourself 15 minutes and you can have the basics covered. I see it really as no different than on camera. Just with better results.

Just take a few minutes and test some ideas. Move it closer take a shot....move it farther, take a shot. Move it more to the side..... you get the idea. Just play with it. I swear in 15 minutes you will have the basic understanding. Sure you will have to make adjustments for different subjects. But you will know what each adjustment will do for you.

Light meters are even less dangerous than off camera flash. They may look intimidating. But they are a tool well worth learning.

A light meter is one of the best investments you can make when starting down the path of off camera flash.

well thank you all so much for your words...
I just get overwhelmed by new concepts...and I just have to do what I normally do
read read and put it to use...
Ill start out with what rene damkot said...
then maybe Ill think about that light meter hahaha

I am not sure if this is allowed, mods please tell me if Im wronged by asking a second question, which of course pertains to my thread, but
if you are using hot shoe flashes off your camera...
how do you focus your lens on the subject if there is little to no ambient light in the room...? because I have no modeling light...

Put on some more lights in the room?

rocker83 wrote in post #5536793
I am not sure if this is allowed, mods please tell me if Im wronged by asking a second question, which of course pertains to my thread, but
if you are using hot shoe flashes off your camera...
how do you focus your lens on the subject if there is little to no ambient light in the room...? because I have no modeling light...

I have and LED light on my keychain that works in a pinch. Light up the object, focus, turn the light off, fire.

Keep in mind, with the right settings and enough light to focus in, you can completely over ride the ambient. I was shooting in my dining room with the light over the table on and I was completely killing it with my flashes.

Also. Make a cheat sheet.

Sigma ef-super 500 flash guide number(GN) is 165 feet at ISO 100 with the flash at full power.

GN = distance x f-stop

so, cut the power in half and the GN drops to 82.5

@ 1/2 power you can shoot at f/8 with the flash 10' away and get close to a proper exposure. That still may be a little far.

Cut it down to 1/4 power and the GN should fall to 41.25'

@ 1/4 power you can shoot at f/8 with the flash about 5' away from the subject.

5' is a good distance and will give you something to work with. Tape a piece of paper to your flash and put 1/4 5' f/8. Your shutter speed won't matter as far as affecting the flash exposure as long as you don't go over the camera's max sync speed.

And from there, you'll know when setting up to put the flash about 5' away and start at iso 100 and f/8. You can of course move the flash or use and umbrella, but remember you'll have to compensate with flash power or your aperture.

rocker83 wrote in post #5536793
I am not sure if this is allowed, mods please tell me if Im wronged by asking a second question, which of course pertains to my thread, but
if you are using hot shoe flashes off your camera...
how do you focus your lens on the subject if there is little to no ambient light in the room...? because I have no modeling light...

Speedlites have a focus assist beam, else you have to add light some other way.