DC-s hood noob question

[SPL Tech1]

I have a few questions about this new hood I bought for my 40D.

1. What does DC-s stand for? Is it some class or is it a brand or model or what?

2. I have read that a flower hood offers just as much protection as a symmetrical hood. However I am not seeing the physics behind how that’s possible. If the point of the hood is to stop direct sunlight from hitting the lens, the effectiveness of such will be determined by how long the hood is. The longer it is, the shallower the angle of the sun can be in relation with the lens on a parallel plain. With this flower design it seems as if it would not offer nearly as adequate protection from direct sunlight from over the shallower corners of the hood then over the longer corners of the hood. Is this correct? If not can someone explain how the flower design is just as good?

3. Does this hood actually do anything? I could understand if someone was shining a spotlight at the camera from the side, but will I actually notice a improvement in my pictures considering that I can’t recall a single picture I have ever taken that has lens flairs from the sun in it (not saying that I am a good photographer, but that it does not seem like lens flair occurs much if you’re not shooting straight into the sun)?

4. Does it matter how the hood is orientated on the lens? Does it need to be in the position shown in the picture or can it be placed on the lens in any manner?

 

[Steph]

If you type 'petal hood' in the search field of this very forum, you'll find the answers to your questions. Here is an interesting thread from such a search.