Olymics and Lenses

[Photo Phil]

Hope this is the right place. I have been watching the mens and womens swimming this past week and I have noticed in the background press/photographers with huge lenses,I mean huge. Whats the deal with the 1' or longer lenses that have like a 3-4" opening on it. what are the benefits to it. Are they just really expense zoom lenses. Don't get me wrong, they look cool and all but I was Just curious as to why.

Thanks

 

[Montana]

Longer for build reasons....telephoto and number of elements and groups.

 

[table1349]

The benefits are that on the sidelines of a college or pro football game and you fill the frame with a speeding linebacker, he's not going to crush you. If you are shooting swimmers and want a face shot of the effort they are expending you don't have to be in the pool and if you are shooting bears in the backwoods and want a shot of the bear that fills the frame nicely, you are not close enough to be the bears next meal.

Super Telephoto lenses get you very close to the action with out having to be close to the action.

 

[icassell]

The faster the lens (the larger available aperture), the larger the lens. The more telephoto, the larger the lens. Add these together and when you get a fast telephoto, they can be ginormous (and expensive).

http://www.bhphotovideo.com/c/find/newsLetter/Mother-of-All-L-Lenses.jsp

 

[Photo Phil]

Thanks for the fast replies. That makes alot of sense. The question has been sitting in my head for a few days now bugging me.

 

[Syndac]

From what I've seen, the most common canon (white lens) at the olympics seems to be the 400mm 2.8L IS: http://www.the-digital-picture.com/Reviews/Canon-EF-400mm-f-2.8-L-IS-USM-Lens-Review.aspx

If I were a canon user I'd definitely have that on my christmas list, it looks sexy as hell.

I'm not 100% positive on the nikons but I'd assume they're using the same thing, they appear to be anyways.

 

[prodigy2k7]

Most of the reason for the size is for indoor lighting (Big aperture needed; such as F/2 or F/2.8)

The biggest part of those big lenses are probably the lens hoods! The biggest piece on the end is the lens hood, they are probably half the size of the lens itself! (all are different)...

 

[Dao]

I believe in order to collect enough lights in a short period of time, you need a big glass in the front.

Remember the experiment of using a magnifying glass under the sun and focus the light to a tiny little point. And the energy is strong enough to lit up a paper? Same principle. The lens is collecting the light from that big opening and bend and direct them to the small sensor in the camera. So every single point on the sensor will have more light (or say, more concentrated light) land on it.

 

[Overread]

I suspect many there were wishing for the sigma bazooka
http://www.sigma-imaging-uk.com/lenses/telezoom/200-500mm.htm
heck not even a canon prime 500mm is f2.8!

Though weight might be a drawback

 

[prodigy2k7]

That lens is almost impractical lol...

Its all about the aperture, obviously the aperture has to be larger if the focal length is longer... So, the bigger the focal length the bigger the front element will surely be...