Lighting Ratios

When you use more than one flash, you can adjust each light individually. If you use speedlights and your camera maker’s wireless TTL functionality, you can do that in two ways:

  • Canon: relative, using ratios. As in “A:B = 4:1” meaning A is 4x (two stops) lighter than B
  • Nikon: absolute, by adjusting individually. E.g. “A = No adjustment; B = -2 stops adjustment”.

An example of this using two Canon flashes.

Ratio between key light (face) and background light: 1:2

1:1:

2:1 (you are getting the hand signals by now I presume):

4:1:

The preference is yours: mine is 2:1. But that is largely a matter of taste.

If you use manual flash and radio triggers, it is conceptually easier, since you set up each flash by itself, independent of other flashes. Ratios are a little bit trickier to get your head around, because it is not immediately clear which flash will get darker and which flash lighter, and to what extent. So trial and error will be required. Either way, key point is that you should think carefully about how bright each flash is, in a multi-flash setup.

 

Through The Eye Of A Woman

OK, maybe that title is a little silly. But it IS through the eye of a woman that I shone my flash

And here, lit from the back:

Macro lens, 1/80 sec, f/16, 100 ISO, hand held.

The flash was shining from the back. This can give you pretty weird effects:

My eye here looks light green, while in fact it is light blue. Back lighting can do that.

But go back to the first shot. See that? Look carefully. A little white point, in the centre of the pupil,next to the actual catch light.

This is mysterious, because I was using an off-camera flash. The on-camera flash only sends “morse code”, as it were, to the other flashes, before the shot is made.

And yet, that pin light is from the on camera flash.

Simple, actually: it is its afterglow. The flash is off, but it takes a fraction of a second to completely go out, and it is during that fraction of a second that the shot is made. Here, the proof:

See, the main flash on our left, bounced against the wall; and me and the camera including its popup flash afterglow in the centre:

And that is why you get a little pin of extra catchlight in some wireless TTL photos, even though your on camera flash is turned off.

(Thanks to Becky for the loan of an eye!)

 

Friday the 13th.

..is not a bad day so far. I am shooting an event tonight; first, some more writing (the Travel Photography book: I am making good progress and I trust I will have it finished before Xmas), and some admin.

A quick note, today, about TTL flash. You can of course set up a studio setup with manual flash, and when you have time, you do that. But when you do not have time, use TTL for off camera flash. Remember:

  • Use flash exposure compensation when needed (when the camera decides to over- or under-expose the shot).
  • Avoid reflections.
  • Meter off something mid grey.
  • Disable your on camera flash (so that it sends commands, nothing more).
  • If you have two flashes, set them to “A” and “B”.

Now set ratios between groups (Canon) or adjust groups to taste one by one, by stops (Nikon).

I had two flashes here: main flash A on the left; hairlight B on the right.

A:B = 1:1 (Canon) or A and B both set to 0 FEC (Nikon):

A:B 8:1 (Canon) or B -3 stops FEC (Nikon)

A:B 1:8, or A -3 stops FEC (Nikon):

Although the way of setting them differs a little (ratios vs per-group adjustments), the end result is the same. And the benefit of using TTL for this is that it is very fast. TTL with some knowledge and some adjustments when needed, and Bob’s your uncle. Try it, if you have several flashes.

 

 

Wednesday Possibilities

Today, some shots to get your imagination going – shots that show how much is possible with little effort, and quickly. Shots I took in and between classes in mere seconds, to demonstrate specific points.

Like this quick demonstration shot showing what a great modern camera like my 1Dx can do at – wait for it – 51,200 ISO:

Meaning that with a new camera, you can now photograph pretty much in the dark, or mix a little flash with very low ambient light, or bounce off very high ceilings.

Especially when using off-camera flash, that opens up all sorts of possibilities. Here’s a demo shot showing what a little extra light can do; look carefully and you will see that I am using remote TTL flash (where my camera’s flash is the “master”), and my student at Sheridan college has set his flash to be the “slave”:

Result: he is temporarily blinded… and lit up. You can do that too, with very little extra equipment. One flash, if you have a moden camera whose popup can “command” external flashes; else, two flashes, on on the camera and one remote. Imagine what you can do when you can add a little light everywhere you like!

Then, another student lit dramatically – from below! This kind of eerie effect is easy once you can take your flash off the camera as desribed above.

Or – just turn the camera upside down and bounce flash off the table, as I did!

Off-camera handheld flash gives me this image, even when the flash is aimed direct, of Mr Jun:

Not bad, and that is direct light aimed into his face – as long as it is not near the camera, the flash can be unmodified and direct!

And when you have several flashes, you can do things like this:

Now that is a competent portrait, taken in just a few seconds, using this setup with two off-camera flashes each fitted with a Honlphoto grid, and one with a blue-green gel; using two “biological light stands”:

But finally – do you need all those flashes? No, here’s a portrait using one flash fitted with a Honlphoto 8″ softbox:

The apparent Martian in the background adds a little extra “huh?” to this photo, don’t you think? His glasses reflect the round softbox.

Anyway, these snaps demonstrate that you can achieve a lot in a very short time using simple means – you may already have every thing you need. Get creative, go outside the box, and above all, think “where is the light coming from”!

 

What you need

A studio setup usually uses big, wall-outlet powered lights (“strobes”) and more.

But here’s me, on a recent shoot:

As you see, I used speedlights there. They are smaller, lighter, easier.

The setup was:

  1. Camera and a backdrop.
  2. Two light stands.
  3. On each light stand, a bracket for mounting umbrella and flash.
  4. On each light stand, a Pocketwizard (as received) and a Flashzebra cable to connect pocketwizard to flash.
  5. Pocketwizard on camera (as sender).

All you need to do simple portraits like this:

But the real minimum is this:

1. One light stand

2. One bracket like this:

3. One remote flash to put on that bracket

4. One umbrella to put into that bracket

5. One way to fire the remote flash using TTL (the on camera flash is set to not flash, but to just send “morse code” commands to the remote flash). This local master flash can be a large flash (SB-900, 600EX) on your camera, or on certain cameras like most Nikons and many recent Canons, the pop-up flash.

And that is really all as a minimum!

When using that, you simply mix available light with flash, using the techniques outlined on this blog. Then you can do shots like this, of Dan and Kristen, whose engagement photos I made recently in Hamilton: