The Nuts and Bolts of off-camera flash – Part 1, Basics

So unless you’ve been living under a rock (photographically speaking) for the past year or so, you’ve probably heard of David Hobby, AKA The Strobist.  The strobist blog has been singlehandedly responsible for introducing a whole new wave of photographers to the beauty and mystery that is: off camera lighting!

The problem is – a lot of this stuff is still confusing.  Heck, I didn’t “get it” the first time I read through lighting101.  Or the second.  Or probably not even the third.  And a lot of the time, the problem isn’t conceptual, it often comes down to the “nuts-and-bolts” issues – eg, things like “what works with what”, “how do I connect x to y” and “why is there a black bar across my image when I use my flash off camera but not on camera”

What I am going to do in this series of articles, is break down, step-by-step the various hardware and methods needed to get your flash off camera and firing properly.  We’re not going to worry about lighting theory or anything like that – just the “nuts and bolts”.

  • In par 1 (here) we’re going to talk about the basics of how a flash works, and the different modes you can use it in.
  • In part 2 we will discuss options for manual triggering.
  • In part 3 we will discuss wireless ttl flash
  • and finally in part 4 we will deal with some miscellaneous topics, such as x-sync, HSS, rear-curtain sync etc…

So without further ado, lets talk about getting your flash out of the hotshoe and into the wild where it belongs!

Now first of all it is important to understand how a flash actually fires.  In actuality it is quite simple – if you look at the bottom of your flash (or “foot”) there is an electrical contact, the center pin.  If you have a newer “system” flash, it may have other pins as well, but they all have the one center pin.  Now if you look at the inner sides of the foot, they are also metal.   When a connection is made between the center pin and the sides of the foot, the flash fires.

That’s it.  You could make your flash fire by connecting these two contacts with a paperclip even. (although I wouldn’t recommend it and am not responsible if you electrocute yourself trying it!)

So in essence, triggering your flash is simply a matter of making the connection that allows it to release it’s charge as a burst of light.   The catch, of course, is *how we make this connection*.

Now let’s step back for a minute.  Before we think about triggering the flash lets look at the primary “modes” of the flash.   In essence, a flash only has 1 adjustment – power.  In other words, “how much light does it put out when it pops”.  However, there are several ways of *calculating* how much power is needed or desired for a particular situation.

  1. manual.  Back in the day, all flashes were manual, meaning they were essentially “dumb”  *you* set the power output by hand, based on what you calculated was needed.
  2. auto.  auto flash is basically a way that the flash itself measures the amount of light needed based on settings you input.  We will not talk be talking much about auto-flash since I believe manual or ttl are more useful 99% of the time.
  3. TTL.  Stands for “Through The Lens”, and is a method where the camera and flash “talk” to each other and calculate the appropriate amount of flash automatically based on the camera settings and a meter reading.

For purposes of this discussion, we are just going to talk about manual and ttl flash, as I think they are the most useful.    The point to all this is that, despite having the same outcome (firing the flash) the *methods* for triggering your flash are very different depending on whether you will be using manual mode or TTL.

In part 2 we will talk about options for triggering your flash in manual mode, what kind of hardware you need for each, and pros and cons for each option.  Stay tuned!

UPDATE:  part 2 is now up – find it here

23 thoughts on “The Nuts and Bolts of off-camera flash – Part 1, Basics”

  1. Ed… I think… I love you, man. THIS is the kind of stuff that I need help with when it comes to lighting. I’m really looking forward to this series of articles. Hopefully by the end of it I’ll be comfortable with the thought of buying some gear and actually using it.

  2. I am so looking forward to this even though I have no plans to do off-camera flash photography any time soon. I am hoping simply to learn more about flash so I can better understand how to use my on-camera SB-600.

    I agree that this topic can always be broken down further, into more little pieces, to help us take it in.

  3. I have been reading the Strobist and confused doesnt even began to describe how I feel, Thank you so much

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  5. Thanks for the tip! If you see my website:, you will notice that a lot of my images have been clicked with the use of Flash because the weddings are usually in the evenings (low-light set-ups).

    I am using Canon 580EXII and I would like to use it as an off-camera flash. The option for doing this is that I buy the canon ST E-2 trigger-as this does not need to be in the optical line of sight of the flashgun (unlike the third party triggers).

    But I am told that the ST E-2 cannot trigger the 600 RT and ALSO that that ST E3 which can trigger the 600 RT CANNOT trigger 580 EXII. I am stuck because I don’t wan a be stuck with the ST E2 on the long run. But even if I buy the ST E3, it will not help me with the 580 EX II. And I cannot blow my money on 600RT AND a ST E3 now.

    Any suggestions?


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