ANOTHER ANSWER (following question changes) :
What impact, in general, does it make to choose :
- A high point of view, above the scene ?
It gives a feeling of power to the observer. You are ABOVE the scene, you dominate it. You can "control" what is on the picture. Taking landscape and you could be a god who created that, a bird that is not affected by the elements, ... Taking a portrait you could be a father or a mother, an higher person, someone who exercise a domination on your subject, ...
- A eye-level point of view, at normal human height?
It's a general point of view. You see things like many other people. There are no special feeling. But what is eye-level if there are nobody in the picture ? It depends on who should be impressed by the picture. Taking a picture at children eye-level would not have the same impact for a children viewer and an adult viewer. You should take care of the public you want to touch with your picture.
Another thing to take into account is the kind of lens you use. Being at eye level does not imply that you take pictures like everybody can see the scene. For example, if you use a wide angle lens, and take a monument or a lanscape, you may include in the photo more objects than a normal eye can see. If you move your camera a litle bit down or up, then you change perspective. A normal eye don't see like that too. So you can add, even being at eye level, some dramatic expression on your picture.
- A low-to-the ground "earthworm's view"?
In the opposite of high-level point of view, this one gives the viewer a feeling of being dominated. You do not control anything on the scene. Taking landscape and you could be an earthworm, fragile, ... Taking a portrait you could be a son or a daughter, an higher person, someone who needs protection or is dominated or under the control of the subject, ... Here also, using a wide angle lens can change that a little bit, if you take the pictrue with the camera up. You add dramatic expression, and can shown a large view of the scene. So even if you seem fragile, the dramatic addition and large point of view may let think that you are not so fragile. A little flower taken like that may seem to dominate its surroundings, its little environment, even if it's just a little flower. taking the same flower, with that same POV and a normal lens, and the feeling is not the same. You may isolate the flower, lower the drama expression, taking it like this so the feeling of fragile may be more present.
Do certain types of photography work best with a particular point of view ?
Definitely, no. It just depends on what you want to express. But... if you want to impress, choose a POV that is not common. Classical POV are : eye-level for portraits, low-level for flowers, low-sized objects, ... high-level for large scenes (crown, town, ...). But saying this, I can see in my mind many geat pictures that do the exact opposite.
Low-level :
Nature :
http://1x.com/photo/44881/portfolio/67762
http://1x.com/photo/46927/portfolio/96704
http://1x.com/photo/46253/portfolio/48485
Portrait :
http://www.zphoto.fr/aurelia_photo652435.html
http://1x.com/photo/46313/portfolio/61156
http://1x.com/photo/247/portfolio/42
Landscape :
http://1x.com/photo/46223/portfolio/63062
http://1x.com/photo/44582/portfolio/37923
Eye-level :
Nature :
http://1x.com/photo/47005/portfolio/137168
http://1x.com/photo/46271/portfolio/11929
Portrait :
http://1x.com/photo/46346/portfolio/29189
http://1x.com/photo/46293/portfolio/11824
Landscape :
http://1x.com/photo/46430/portfolio/101715
http://1x.com/photo/46381/portfolio/130137
http://1x.com/photo/46260/portfolio/130808
High-level :
Nature :
http://1x.com/photo/46031/portfolio/75215
http://1x.com/photo/45161/portfolio/57812
Portrait :
http://1x.com/photo/1494/portfolio/22
http://1x.com/photo/46718/portfolio/138079
http://www.zphoto.fr/enfant_de_ganvie_photo653449.html
Landscape :
http://1x.com/photo/47002/portfolio/141698
http://1x.com/photo/46842/portfolio/19773