Should you use a DSLR with a flash gun and diffuser outside?

Answer 1

Using a diffuser will require you to be fairly close to get much effect, especially if the light is bright. Depending on how powerful the flash is, you can use fill with minus compensation for a kiss of light in the shade, or use more power to even the exposure in the bright sun, and eliminate raccoon eyes and harsh shadows.

Answer 2

For portraits, sometimes but not always. If you have even lighting conditions and skylight is bright enough you can on an overcast day, get a soft pleasing portrait. Using too much flash on people can look unnatural.
I like using flash on subjects when back lighting is more to the side and the result then is a halo effect and quite nice. It's more
dramatic but very pleasing.
My best advice is to experiment It's the best way to learn.

Answer 3

absolutely, as fill flash, when taking pictures in back lit conditions (camera facing into the sun). A flash can help get the exposure right on the foreground and avoid dark shadows.

You can also use it as a light modifier for pictures under poor light. Over-cast portraits are a huge one. The flash lighting is warmer than an overcast so when taking overcast portraits I usually use a fill flash to get nice warm skin tones. you can also use a gold reflector for the latter but a flash is more portable.

Answer 4

for people shots absolutely, a bit of fill flash will remove nose shaddows and give a sparkle to the eyes

a