I thought it would be useful to post this image and walk through what I did to get the shot. From talking to a lot of photographers I know that flash is a subject that many find quite daunting to the point that they never learn it but for portraiture, in my opinion, it's essential. Natural light can be great but why not have the ability to bring your own light and put it where you need it. I’ll add this right now... I am no expert, I just learn from doing and observing the results, rinse and repeat… as well as a healthy dose of YouTube flash tutorials.
So this shot was taken at Play Expo, Event City, Manchester with Captain Amelia Cosplay as Alice in Wonderland and we took a short walk across the road to the Trafford Centre to do a shoot.
This was shot with a manual flash, a Rogue Flashbender diffusion panel (basically a portable softbox that folds flat) on a short lightstand positioned camera left. With a manual flash you dial in the power yourself, from 1/128 to 1/1 (full power) and as far as I understand it, manual flashes are more suited to static subjects where the subject to flash distance isn't changing.
First thing, I took a test shot without the cosplayer or flash to get the background right and dialed in 1/160 (my flash sync speed is a maximum of 1/200s), f8, ISO 200.
Then I moved the cosplayer and the flash into position. Now, because I was shooting at 11mm I had to put the flash quite far away, maybe about 6-8 ft (normally I position it a few feet away) otherwise it would appear in the shot, so I set the flash to full power and took a test shot. That was way too powerful, so I reduced it to 1/2 power and that looked fine. And that's it, once you've dialed in your settings, they stay roughly in that location and the ambient doesn't change, you can just shoot.
So even in daylight, bringing your own lighting can be incredibly useful when on location. Without flash this wouldn't have worked as well, it was an overcast day and the lighting was just too flat. So next time you're out, I recommend you go ahead and try it.