Focus Tip: AF-C/AI-Servo and back button focus

I am often asked “can I not leave my camera on AI-Servo (AF-C if you are a Nikon etc)?

The answer is: not a great idea normally. Because you cannot recompose. The moment you try that, taking your focus spot(s) away from your subject, the camera focuses on whatever is behind the subject!

But there is a trick, and I used it today to photograph these amazing insects:

Namely this:

  1. Set your autofocus mode to AI Servo/AF-C.
  2. Select “back button focus” in your camera’s menu (i.e. focus when you press a button on the back of the camera, not whenever you half-press the shutter button).

Now you focus as follows:

  1. Follow the insect, or hockey player, or whatever you are shooting.
  2. While doing this, keep the back button focus pressed, so your camera adjusts to follow the subject’s distance.
  3. But when the butterfly sits and you want to recompose, let go of the back buttoin focus. You can now move the camera to recompose, yet when you shoot, the camera will not adjust its focus.

Done and done!

A quick note about that amazing insect. Nature knows what many beginning photographers do not: you need a catch light in the eye to make it look real and alive. The butterfly’s owl eye has that catch light (the white circle part ion the “pupil”)! Amazing, eh? So learn from nature and always include a catchlight in your portraits.


Mnemonic Monday

OK, it’s not Monday, but that alliterates.

You all remember my mnemonic “400-40-4” for indoors flash for events? If not, read up on the Willems 400-40-4 rule for ISO, shutter and aperture.

I have another one for you: 4000-400-4. That is 4000 ISO, 1/400 sec, and f/4. And that is for hockey in a well lit hockey arena. Easy to remember, and results are thus:

200 mm lens, 4000 ISO, f/4, 1/400 sec, stabilizer mode 2

Have fun!

Warm day

It was a warm-ish day today, so I went and took some car photos.

Since the sun was out, it is no surprise that I found available light a little boring:


So.. I added a flash, on a light stand. But as you will have guessed one flash was, of course, not enough to light a big subject like a car…:


…so I added two flashes. Left flash: half power manual 600EX, aimed direct at the car starboard side (zoom=50mm). Right flash: half power manual 430EX, aimed direct at the car front (zoom=50mm).

And that gave me this photo:


Desaturated slightly; otherwise this is the way I shot it.

But… say what—Two light stands? Fired by pocketwizards? Isn’t that complicated?

Yes, yes, and no, respectively. It is not complicated. And the results, as you see, get you immediately beyond the “snapshot”. And that is satisfying.

Michael teaches flash and other photography subjects; at Sheridan College and privately; and at his own school. If you want to know more, come to one of my regular courses (see

An Essential Tool

If you take your photography seriously, you need to avoid one thing in particular: running out of battery power just when you need it. (Have you noticed, batteries never fail at a convenient time?)

The solution is simple. Buy a battery tester, and use it before you go and shoot.

A battery tester, which sells for about $7–10 in your hardware store, is a meter with a “battery” mode. That mode does not just measure voltage; instead, it measures voltage under load.


You recognize it by its mention of batteries (like “AA”, as in this example).

Before every shoot, measure your batteries, and if in any doubt, replace them. That takes away one big drawback of battery-powered equipment.

  • Where do you use rechargeables? A: In gear that you use intensively and often: namely, in your flashes.
  • Where do you use Alkalines? A: In equipment that uses little current and that lasts many months between battery changes. Namely, in your PocketWizards and similar radio triggers.

One more note: if you use rechargeable batteries, make sure that you use an appropriate meter. NiMH batteries have a lower voltage than Alkaline batteries, so you cannot measure NiMH batteries with a meter intended for Alkalines (or vice versa).


Time and space

Sign up now: there’s time and space to learn all about flash. A model and make-up artist will be supplied for the workshop I am teaching on January 28 in Toronto. In this workshop, from knowing “nothing”, you will learn creative flash in half a day.


Recent single flash shot. Studio settings; manual; off-camera; 1/8″ grid.

And this includes:

  • Setting up your camera for flash.
  • Why use flash when it’s bright outside?
  • TTL or manual flash: Why go manual, and when?
  • Speedlights or studio strobes?
  • What are the limits to using speedlights?
  • Modifiers: gels
  • Modifiers: grids and snoots
  • Modifiers: softboxes and umbrellas.
  • “Magic recipes”: shortcuts for outdoors, indoors, and studio flash.
  • Common mistakes – and avoiding them.
  • Off-camera flash: How? Why?
  • Using radio triggers (which ones?)
  • Secrets of creative lighting – examples with model and make-up artist.

You will leave with a few great portfolio shots, but also with an understanding of, and “quick start” recipes for, handling each flash situation that you will come across.

This course is intended for everyone from beginner to pro. What you have in common is that you have an SLR camera, you know little about flash, and you want to learn all about it. Bring your camera! If you have a flash, bring it; if not, no worries: everything is supplied.

There are spots left but space is limited, so sign up now.