| Author | Thread |
|
|
09/19/2014 01:36:40 PM · #26 |
Originally posted by Garry:
One buys a 2.8 presumably to use it wide open or not far from it. So, with a 2.8, just how important is the IS? |
Actually, one buys a 2.8 as much for improved focusing precision as anything else. |
|
|
|
09/19/2014 04:28:42 PM · #27 |
| Never heard of aperture affecting focus. |
|
|
|
09/19/2014 04:51:46 PM · #28 |
Originally posted by Garry:
Never heard of aperture affecting focus. |
Ohhh yes.
Consider: The lens focuses with the aperture wide open, so an f/2.8 lens has twice the light for the AF system to work with. In addition, the f/2.8 aperture gives narrower DoF, so AF can be more precise.
|
|
|
|
09/24/2014 07:46:31 PM · #29 |
Ordered 70-200 f2.8 ii from Canon Refurbished, it was available for $1850.00+tx.
Now next is I am going to put my 70-200 f4.0 on sell and so do Sigma 10-20mm. |
|
|
|
09/24/2014 07:55:29 PM · #30 |
Originally posted by kirbic:
Originally posted by Garry:
Never heard of aperture affecting focus. |
Ohhh yes.
Consider: The lens focuses with the aperture wide open, so an f/2.8 lens has twice the light for the AF system to work with. In addition, the f/2.8 aperture gives narrower DoF, so AF can be more precise. |
In theory, yes. I don't know about the Canon 70-200's, but in practice, I'd be hard pressed to find any useful difference in focus speed between the Nikon 70-200 f/2.8 vs the f/4. They're both pretty much insta-focus, even in low light. |
|
|
|
10/01/2014 09:54:08 PM · #31 |
First shot with 70-200 2.8 version 2
 |
|
|
|
10/02/2014 07:54:59 AM · #32 |
Originally posted by kirbic:
Originally posted by Garry:
Never heard of aperture affecting focus. |
Ohhh yes.
Consider: The lens focuses with the aperture wide open, so an f/2.8 lens has twice the light for the AF system to work with. In addition, the f/2.8 aperture gives narrower DoF, so AF can be more precise. |
also, type if your camera has cross type sensors only work at 2.8 and wider if i'm not mistaken. otherwise they only work as single line sensors. |
|
|
|
10/02/2014 08:46:31 AM · #33 |
Originally posted by pgirish007:
First shot with 70-200 2.8 version 2 |
Illuminating! :-)
|
|
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 05:38:42 AM EDT.
