Summer's day shoot, on a dull late evening
OK, take a look at the shot above. Deconstruct the light. How do you think it was shot? What lighting was involved? What was the ambient light like?
If I said it was dark, miserable and cloudy with no sunlight, about 9pm at night, would you be surprised?
We'd been looking to do a shoot on a nice sunny evening, with a casual style in a wheat field. There were a few problems, not least there were virtually no sunny evenings going (all rain or dull) and by the time we got the shoot arranged, the farmers had all just done their harvesting!
Suffice to say, we ended up in a field just off the side of an industrial estate, in very low grey-blue light, having to invent a little summer.
What you will have figured out by now is that there were two light sources. One from camera right lighting the model's face, and one from camera left, over his shoulder. The one from camera right looks like flash, and you probably even guessed that it was a bare flash from the catchlight. You'd be correct. The other source of light hopefully passed as sunlight without much of a thought, if I did my job well enough. Again it's a bare flash.
The trick to this was a couple of CTB filters which cool the light output from the flash. On the flash to camera right I used a full CTB filter, and on the flash to camera left, I used a half CTB filter. When I shot the images, this gave a horribly blue tone to the model, which probably un-nerved him just a touch as I showed him the back of the camera.
The secret is that you're making the daylight balanced flashes cool so that they put out a colder light than the already blue-ish ambient light. When you process the raw file out the camera, you then warm the image right up to about 14,000K, and a slight tint change if necessary. The ambient goes a warm summery glow, your half CTB filter looks slightly warmer like sunshine, and your full CTB looks just enough cooler to look like normal daylight flash used at sunset.
There really is no excuse for blaming the weather for a lack of good shots!