There are times when you want to capture something delicate in backlit lighting – a translucent flower for example. Going strictly with the natural light you end up with either the translucent parts blown out to get detail into the front, or you have a dark blob in the middle to keep the delicate highlights under control. This is where fill flash comes in handy.
Normally I loathe little pop-up or shoe-mounted flashes because they’re about useless when trying to light anything more than a couple feet away, and they’re so close to the lens that they give people red eye and make pets look like demons. But as a fill flash, they really shine (shine, get it? pun!). They put out just enough light to take the edge off backlit shadows and add a little catchlight into people’s eyes. When used this way redeye isn’t a problem because in daylight people’s pupils are closed down enough that their retinas don’t reflect (the cause of red eye in photos).
Fortunately, flowers don’t have retinas, so we can dismiss the concern altogether.

I was using my Fuji X-T1 and had the tiny little toy-like pop-up flash that comes with the camera as an accessory. I took one shot of the blossoms without the flash. I knew right away that the blossoms would be too dark and not have detail; the little flash was exactly what I needed. I popped it up and let it put in a little kick. Voila!