| Author | Thread |
|
|
06/16/2006 05:13:35 AM · #1 |
I recently recieved a Canon 30d (yay!) with a Canon 24-70mm f2.8L lens. But I'm wondering why the extension of the lens is reversed from most lenses?
Most zoom lenses extend out (get longer) when you zoom in and retract in (get shorter) when you zoom out. Why does this lens work in reverse (the wide angle is from its furthest extended out positions and the telephoto is from its furthest retracted in position).
Wikipedia explains it this way:
"A unique aspect of the 28-70mm f/2.8L and the 24-70mm f/2.8L is that they extend as they zoom toward their widest range. This in itself is uninteresting [which I do find interesting]; however, when paired with the supplied lens hood (which attaches below the extending portion of the lens, allowing the lens to extend through the hood), this extension results in a perfectly matched hood from telephoto to wide angle. This is in sharp contrast to the standard zoom lens hood that is designed for only the widest setting and therefore provides less-than-ideal shading for any other setting along the zoom range."
Is this the only reason? Or is there some other reason for this enigma?
|
|
|
|
06/16/2006 09:04:20 AM · #2 |
Congrats on the new camera! Your work was phenomenal with your other cameras, I can't wait to see what you're able to do with this setup!
I was wondering about the same thing when I got my 24-70. My guess was what Wikipedia says about the hood. It seems kind of strange to engineer a lens around the hood, but makes sense. |
|
|
|
06/16/2006 12:38:57 PM · #3 |
|
|
|
06/16/2006 01:06:57 PM · #4 |
Busted - Didn't read the full question :-)
Message edited by author 2006-06-16 13:22:39. |
|
|
|
06/16/2006 01:22:55 PM · #5 |
Originally posted by robs:
isn't the hood attached to the barrel not the end of the lens and therefore the hood stays in the same place. |
Exactly. It's wierd putting the hood on the first few times. |
|
|
|
06/16/2006 01:57:46 PM · #6 |
Is that the only reason? It makes a lot a sense, why don't other lenses do that as well if it works so well?
|
|
|
|
06/16/2006 02:38:18 PM · #7 |
I'm not sure it was designed specifically *for* that feature, as much as it's design probably just happened to allow that feature... but it sure is a nice feature! It is a strange optical system, but not unheard of. In fact, I had a Tamron 19-35 that was shortest somewhere in mid-zoom, and longer at both the wide and long ends!
Congrats on the new kit, BTW. The 30D+24-70L is going to be an awesome combination. You do know, though, that for striking landscapes of Cannon Beach, you'll need that Canon 10-22! |
|
|
|
06/16/2006 03:53:14 PM · #8 |
Originally posted by kirbic:
I'm not sure it was designed specifically *for* that feature, as much as it's design probably just happened to allow that feature... but it sure is a nice feature! It is a strange optical system, but not unheard of. In fact, I had a Tamron 19-35 that was shortest somewhere in mid-zoom, and longer at both the wide and long ends!
Congrats on the new kit, BTW. The 30D+24-70L is going to be an awesome combination. You do know, though, that for striking landscapes of Cannon Beach, you'll need that Canon 10-22! |
The kit lens does the double movement thing as well. I think it's a great idea with the fixed hood mount but I have no lens that does it :-( I figure they have a better reason then just the hood but maybe not - your 5D has a direct print button right :-)
If it bothers you, just mail it to me and you don't have to think about it - I will happily pay the postage :-)) Great combo - Enjoy. |
|
Home -
Challenges -
Community -
League -
Photos -
Cameras -
Lenses -
Learn -
Help -
Terms of Use -
Privacy -
Top ^
DPChallenge, and website content and design, Copyright © 2001-2025 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Current Server Time: 09/06/2025 11:46:14 AM EDT.
