Nature of Elvish Cloaks
This wiki article appears to list all the main points that elven cloaks came into play in Tolkien's works. It seems clear that both in the books and the movie that the idea was enhanced camouflage, not invisibility (as the One Ring gave).
What is not clear from the article is how "active" one had to be in making this camouflage work. It would seem that, barring making a bunch of noise, that the cloaks would act rather passively (not requiring that they be "activated" so to speak; indeed, the wiki article seems to indicate that the elves did not even really consider them "magic" per se). Of course, to fully camouflage one would need to cover oneself completely (as demonstrated in the movie scene from the Two Towers where Frodo covers he and Sam).
Specific Example
But what elicits my question specifically is scenes such as this one, where in the background you can see the hobbits sleeping (Frodo I think specifically), and distinguish both his head and his legs. When sleeping in dangerous country, it would seem most prudent to cover oneself completely with the cloak when bedding down, so that one might look like a rock, tree, bush, whatever while slumbering.
Specific Questions
- THE MAIN QUESTION: Is there anything in Tolkien's lore that would indicate the cloaks needed more conscious involvement (hence, while sleeping they would not cloak).
- If (1) is true, the cloaks need more active use, are there clear examples in the books where members of the original fellowship are "spotted" even though "hiding," showing they were not utilizing the benefits of the cloak? In the movie I can think of the scene right before Frodo and Sam are captured by the men of Gondor (while peering over the cliff, they are not covering themselves, at least their heads, with the cloaks, which would seem prudent). However, to their credit they moved to that location and from it, so the men of Gondor could have spotted them before or after taking up a "hiding" position on the cliff edge.
- If (1) is false, and passive use was the norm, should we consider the reason the cloaks are not used more, as in such scenes as the sleeping hobbits, to be (a) bad judgment on their part, or (b) bad movie and/or book plot.