The first pic is taken around 9am to 9.30am in the morning. The second is taken close to 12 noon the same day.
Here's the thing :
In the first pic, I used a flash. More specifically I used my F58AM pointed upwards with the bounce card raised. You can see the flash reflected in one of her eyes (catchlights).
The second pic, I did not use flash.
Most people are, how should I put it, "afraid" to use the flash. When they are outside, they usually keep the flash away. They rely on the ambient lighting. Not to say that there's anything wrong with ambient lighting but sometimes ambient is not optimum. Your job as a photographer is to ensure that the light is good and most times that means using the flash.
I usually have my flash out when shooting. I may or may not use it (just a matter of pushing a button on the flash) but the flash is there when I need it. Here's a breakdown of what went on during the shoot for both pics.
For pic 1:
We were in the shade. The sky was overcast and it was hazy. Lighting was dull but you can't say that there's no diffused light. There's plenty of diffused light (overcast skies, shade) but maybe not enough. The EXIF data showed that the shot was taken using a shutter speed of 1/200 which is the max sync speed when I turn the steady shot on. I am using an 85mm lens and looking at the pic, I am not standing too far away. As you can see, the flash did it's job but it not obvious in the pic. That's how I like it. Lifted the shadows on the face a bit and gave the eye it's catchlight though I would have preferred the catchlights in both eyes.
Shooting digital means you can check the result instantaneously. If the flash is too harsh, you can always turn it off and retake the pic. Get it right on cam and your editing time is slashed by a lot.
For pic 2:
It's high noon. Most would say that's the worst time to take pics. They would be right but the sky was overcast and hazy but the light was still harsh so we shot this under shade of a tree. Aperture was at f2 to open the lens up. If you noticed the background on the upper part of the frame, the area under direct sunlight is all washed out. That's why I kept that area to a minimum in the frame. There was a large diffuser but I forget if it was in place or not when I took the pic as the diffuser was also used to fan the model. Haha.
In summary, know your lights. Know how to get diffused light and you should be able to get decent pics under most conditions.
Pop quiz :
See if any of you can tell me how the flash is used in this one

i not really meant to comment picture. just feel that angela perform not as good as usual. maybe she looks tired?