Manual power

The nice thing about setting flash power manually is that it responds to very simple math. Like the inverse square law. Andthat the common shutter speed, aperture and ISO numbers we know are all a stop apart. They lead to tables like this:

SB910/900 or 600/580EX flash. Zoom set to 35mm. Flash held at 2m (6.5’) from subject. Flash not modified.

So if you have a high-end Canon or Nikon flash and you set the Zoom setting to 35mm, when you set your camera to f/16 and ISO value to 100, you get a well exposed picture at about 2 metres (6.5 ft) distance.

A modifier like an umbrella generally takes around 2 stops, so the same table will hold at one metre (half the distance is 4x more light, i.e. two stops more, which would cancel the umbrella’s 2 stops less).

Simple math. And the rest follows simple math, too: increase ISO and you need less power, and open the aperture and you also need less power. As per the table above. A table that can save you a lot of time.


Talking of Which…

As an aside to my appearance as guest host of TWIP in this week’s Episode 406 (, I chose Honlphoto’s Speed Grid as my product of the week. Today, an update.

First, I notice that the grid comes with its own little pouch now:

Now, I see that David Honl also has new products. One is a double rollup for the gels:

Which, when you open it, has space for lots of gels at once. I have over 50 of them in one rollup:

Another development is two new sets of gels: one with 5 different blues, and one with 5 different sets of greens; to wit, these amazing colours:

Aurora Borealis:

Lime Green:


Velvet Green:

Fern Green:

And then there’s a new little bounce card/gobo::

Cool new products. If you are interested in them, go to your local quality high street photography store or get them via this link: and enter “Willems” on the checkout page for an extra 10% discount off the published prices.


Colour. Just because.

That is often my answer when someone asks “why did you use those gels in that picture?. “Because I could”., “Why not”.  And you start adding colour here, there and everywhere. Consider this:

(100 ISO, 1/20 sec, f/16, 24-105 f/4 lens).

Private student Tim made the picture yesterday. And I put the yellow gelled flash inside the car why, exactly? Because otherwise it would be dark. A little colour adds a lot: think matching, or opposite, colours. Deep blue skies go well with yellow: blue and yellow, like red and green, or green and purple, constitute one of nature’s favourite combos.

And it’s so simple, with a Honlphoto gel:

Just strap it onto the speed strap and bingo. (If you do the Honl photo modifiers thing, go and don’t forget code word “Willems” at the end to get another 10% off. Look at the kits: they rock, especially the last one).

I use gelled speedlights to:

  • Add opposites to relieve boredom
  • Warm up cold subjects (half CTO gel does wonders)
  • Get creative
  • Add a little red to skin in low key portraits
  • Correct colour when shooting in tungsten ambient light
  • Turn backgrounds blue

…and so on. Once you get into the habit, you’ll see how good your photography gets. Speedlights, and easy-to-use, sturdy gels, make all this not just possible. They make it convenient and affordable, too.

This site is called the speedlighter for a reason: speedlights unlock the potential. Just get another flash or two, get some gels and other modifiers, and get creative.



It always gives me enormous pleasure to see that this blog is being read. I mean really read, by real people, who put just about as much time into reading it as I put into writing it.

And so it was tonight, with a long-time reader, and new friend, Tim. So I used the opportunity to snap him:

That was “400-40-4″ (see ARTICLES above)  and an on-camera flash bounced on the ceiling on the left, slightly behind me.

But then I thought: let’s pull out the stops and shoot Tim with an off camera flash and the “studio settings” of 1/125 sec, 100/200 ISO, f/8, to make ambient light disappear:

A little post was done to darken the background more, because flash spilled onto it, but it’s essentially SOOC—”Straight Out Of Camera”.

But then I showed Tim what happens when you use a grid on the flash. No light spill everywhere, like in the previous shot. So now the black background is really black:

That’s why the grid is my favourite flash utility. I used a 1/4″ Honl photo  grid; I love the Honl accessories (and as you will recall, readers — and that means you — get an extra 10% off by using this link and discount code “Willems”).  And want to shoot like me? Then get the Speedlighter–approved Master Lighting Kit. It contains all the accessories I use daily in one convenient—and discounted—package.

And let’s finish with…


And now I am so tired I must sleep. Good night!


Know your stuff.

You know the exposure triangle, yes?

They work together. All three of these variable affect exposure (“how bright it is”).

  • For a brighter picture, you go to a higher ISO, or a lower “f-number”, or a slower shutter speed.
  • For a darker picture, the opposite.

And to make things easy, we have “main numbers” for each of the three variables.

  • Each of these main numbers doubles, or halves, the light.
  • We call a doubling, or halving, of the light “one stop”.
  • So the main numbers are one stop apart.

Main numbers are like this:

  • Shutter: …1/8 sec, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000 …
  • ISO: …ISO100, 200, 400, 800, 1600, 3200…
  • Aperture: … f/1.4,  2.0,  2.8,  4.0,  5.6,  8,  11,  16,  22 …

Moving ISO “to the right” in the table above makes things brighter; that’s the definition of ISO sensitivity. Moving aperture and shutter “to the right”, on the other hand, makes things darker. (Why? A faster speed means a quicker click, which means less light gets in. A larger f-number gives us a smaller opening in the lens; that too results in less light).

And these can cancel each other out! So if you make one change that would darken the image by a stop, and at the same time make another change that would brighten the image by a stop, you will end up with the same brightness in the resulting picture.

E.g. moving from 400 ISO to 800 ISO (“brighter”) and at the same time going from 1/60 to 1/125 second (“darker”) would result in the same brightness.

Your camera probably adjusts things in steps of one third of a stop, which means it takes three “clicks” top go from one main number to the next (200 to 400 ISO, or 1/125 to 1/250 sec, of f/5.6 to f/8). But the main numbers are the important ones.

You need to know these numbers off by heart.

That way, you can quickly do mental arithmetic like “Hey, I moved the aperture from f/4 to f/8. My shutter was at 1/1000 of a second. How do I need to set the shutter to get back to the same exposure?”. (The answer is 1/250. But you should be able to do that in your head. Which is very easy once you have the series above, the main numbers, memorised.)

So before you go any further:

  1. Do you understand the above? If now, why not?
  2. Have you actually practiced the above (in manual mode)? Not once or twice, but dozens, hundreds of times?
  3. Have you memorized the main numbers?

If you are a beginner, do the three steps above before you go any further. OK, go ahead. I’ll wait. Because if you think you can really learn photography without knowing and understanding this, you are wrong. And if you think you can understand this without trying this many times, you are also wrong. We call this “wishful thinking”.


Michael ( does custom private training as well as group-based training and classroom training; see Contact him now (416-875-8770 or to set up a date.