Hood - when to use them?

[Pohled]

Hello,

O, a lot of responses! Thank you all! You're very patient with my begginer's question
I've read the tutorial as well, it helped me a little more to understand the flare thing. I mean a little more because I haven't grasped it all yet, but it shall happen with practice.
I liked very much the use of the hood as a shield too. I think that I'm going to do it too.

[amolsan]

Hans,
Thanks a ton. I have started on my existing camera and lenses. I love both of them. Soon will post some pictures for your advise.
One question: will 50mm 1.8D Or 1.4D auto focus on d7k?
Amolsan

[Class A]

The purpose of lens hoods is to prevent non image-forming light from entering the lens. Such light will produce flare in the worst case but will also degrade contrast before any signs of flare are visible. If you are shooting into a light source, hoods do not help. Note for them to be effective, they need to be as long as possible without causing vignetting. Often full-frame lenses are sold with respective full-frames hoods which are than "too short" if the lens is used on an APS-C camera. I put "too short" into quotation marks because obviously the hood helps, but not as much as it could.

Also note that hoods for zooms must be designed to not vignette on the short end of the focal length range. This means that they are rather ineffective for the long end of the focal range.

[Hans]

Hans,
Thanks a ton. I have started on my existing camera and lenses. I love both of them. Soon will post some pictures for your advise.
One question: will 50mm 1.8D Or 1.4D auto focus on d7k?
Amolsan

Yes it will. It has a screw drive in the body like the D90 it replaces so all modern AF lenses have Auto Focus capability with the D7000 (AF, AF-I, AF-D, AF-S all work)