My "two stops" technique

Here’s a quick start tip for using flash indoors.

First, set your camera to:

  • Manual mode
  • f/4
  • 1/60th second
  • 400 ISO

Now check the light meter in your viewfinder. You want it to read about minus two if you point at a representative part of the room.If it reads higher or lower, adjust aperture and shutter speed until it reads -2. If possible, try to keep the shutter between 1/30th and 1/200th second.

By using this method, your ambient lights shows (avoiding black backgrounds), and it becomes your “fill light”, two stops below the key light. And of course while your ambient is set manually, the flash is still automatic.

And finally: bounce that flash off a wall or ceiling behind you!

Reader question

“Why are you in Manual exposure mode when shooting flash indoors?”, asks a reader. I thought that would make an excellent blog question.

So why?

Well, when I shoot flash indoors I have options. These include:

  • S/Tv mode, which is fine because I set the shutter to any value I like, but this has the big drawback that the lens will quite probably not have the aperture value needed to expose well – and also, aperture is the one thing I want to control.

So then next, there’s Aperture mode or Program mode. This works differently on the main brands:

Canon:

  • P: flash speed will not go below 1/60th. This simple engineering decision makes sense, but it can give me dark, “cold” backgrounds. When using a wide lens I want to be able to go slower, like 1/30th, to let in more ambient light.
  • Av: now shutter speed can go as low as it needs to in order to light ambient normally. The big drawback: in a dark room this could lead to very slow shutter speeds – even seconds, which would lead to totally blurred images.

Nikon:

  • A or P: flash speed will not go below 1/60th. This simple engineering decision makes sense, but it can give me dark, “cold” backgrounds. When using a wide lens I want to be able to go slower, like 1/30th, to let in more ambient light.
  • A or P with “slow flash” enabled: now shutter speed can go as low as it needs to in order to light ambient normally. The big drawback: in a dark room this could lead to very slow shutter speeds – even seconds, which would lead to totally blurred images.

So none of those seem quite ideal, do they?

Then there is manual (“M”). In manual exposure mode,

  • I can simply set the aperture and shutter speed that I want. The background will be lit accordingly.
  • But as long as my flash is set to TTL (Canon calls this eTTL; Nikon calls it iTTL), it is still fully metered and automatic, and the camera varies the flash power to light the flash portion of the photo properly. So “manual” is not manual flash – it is just manual background light.

So for that background light, my starting point is to set manual aperture/shutter speed to give me an exposure two stops below ambient. That means the meter points to minus two when I aim at a representative part of the room. That way I get these advantages:

  • Ambient light becomes “fill light”, which is usually 2 stops below the key light.
  • If I aim at a brighter part of the room, is it not likely to be two stops brighter, so it will not be overexposed.
  • If I aim at a darker part of the room, it is still likely to be light enough to be seen.

So try it next time?

Camera on manual and set time and aperture to a value that gives you -2 stops on the meter. Then bounce off a wall and you get well lit images. Like this one, of two very nice young people at the event I was a forum member at, tonight at UofT’s Mississauga campus:

This also shows that I have taken over 10,000 images with my new 1D Mark IV already. And that I always carry a camera, even when I am a speaker, not a shooter.

Family snapshot tip

If you are new to cameras, let me give you a quick tip for the holidays.

When you shoot pictures of your family, use “slow flash” (enable “slow” on Nikon, or use Av mode on Canon)  and an ISO of 400 or even more if it is dark indoors. That allows the background light to show, as well.

You will need flash, too, around the tree. But rather than the popup flash, use an external flash. And above all, do not do this with that flash:

Instead, do this:

That’s right – point the flash backward above you. Your happy snaps (photojournalists call them “grip and grins”)  will be infinitely better.

Pic of the day

Look at this recent newspaper picture of Elizabeth May, the leader of Canada’s Green Party:

I shot that with a 16-35mm lens set to 33mm on a full frame camera. Exposure was 1/60th second at f/2.8 at 800 ISO, using – what else – bounce flash.The wide angle gives the image depth.

But ignore the technical details and ignore politics. Does this not show what a delightful people-person she is? And a politician who does not hide her wine glass when she sees the press gets full marks for integrity.

This is also a good example of a photo where the foreground is blurred and the background is sharp. That is why you pick your own focus point. If you use the “all focus points are used and the camera picks” mode, you will get the foreground object in focus. Which may not be what you want. Which is why photographers use just one focus point mos of the time.

Event shoot

The other day I shot an event. So that meant dark light, high walls, hard to bounce.

“Crisp” means “bright pixels”, so you will sacrifice some crispness when it is dark.

Still – I never point my flash at subjects when it is the main light. So instead, I bounce. I use the wall or ceiling – but when that is too far (and at 800 ISO “too far” is quite far!), I use a Honl bounce card, or a Fong lightsphere, or I just bounce off my hand:

MVWS0730

Um yeah, the theme was “70’s”.

  • I was using a 1Ds MkIII and a 16-35mm f/2.8L lens.
  • I did not want too much noise so I stayed at 800 ISO.
  • I used 1/30th second, f/2.8
  • A wide angle lens means that even at f/2.8, I get nice depth of field.
  • And the slow exposure means I get some nice background light.
  • Flash pointed behind me to the right, and bouncing (I saw a wall not too far).

Everyone else got dark backgrounds; I get this. A fast lens (f/2.8) is quite essential.