I a specific question about exposure/fill.

I guess this is more of a style thing but in another forum someone commented that my exposure is bad and that I needed to use fill via reflector or flash. I think that my exposure is fine as I get enough shadow detail but something like fill I would consider.

Ofcourse this is more of a style and personal choice but is anyone put off by this?

I'm thinking of using a reflector and/or flash for for under harsh conditions like the last image and images like this:

77.jpg

Well I'll have to play around with it, but I worry that using artificial lighting to fill might make things look unnatural...but the trick might be in the skill of lighting.