Best Lens Hood For A Canon 15-85mm Lens?

Hi folks,

I'm looking for recommendations for a lens hood for my 15-85mm lens.

Do I get a full lens hood or  a petal type?

I think the petal one would reverse fit but would a fully enclosed one?

Is it just really very light/sunny conditions when you'd use one?

What's your preferences - full or petal and why?

Thanks very much in advance for your help