Go Back   Steve's Digicams Forums >

LinkBack Thread Tools Search this Thread
Old Aug 18, 2004, 12:05 AM   #1
trueno92's Avatar
Join Date: Jul 2004
Posts: 51

i have no idea how the af sensor works.... i was doing some testing and i put my finger right over the afsensor to block its line of sight with anything and i pointed my z1 at diffeent objects in various lighting conditions and it seemed to work as if it 1. wasn't obstruced, or 2. was just there for decoration.

it would lock focus on everything normally, no problem or delay at all.:?
trueno92 is offline   Reply With Quote
Sponsored Links
Old Aug 18, 2004, 8:32 PM   #2
Senior Member
jawz's Avatar
Join Date: Dec 2002
Posts: 430

--<snip>-- from Steve's review of the Z1
The DiMAGE Z1 employs Rapid AF to ensure sharp images with minimum delay. Rapid AF uses a passive AF sensor to instantly estimate the distance to the subject and the camera's CCD to determine the precise focus point. A high-speed drive focuses the lens quickly and smoothly.
--<end snip>--

I believe what this is all about is that the passive sensor (which you blocked with your finger) is used to give an initial condition (or estimate of focal distance) to the 'normal' contrast-based AF algorithm that uses the image info from the CCD sensor for determining final fine focus. By having a good guess of the distance to the subject, the focus algorithm can reduce the number of trial and error iterations needed to converge on an acceptable focus lock.

Thus by blocking the passive sensor you have slowed down the AF process (by an impercievable amount, perhaps) but it had no effect on the quality of the final focus lock.
jawz is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -5. The time now is 5:49 PM.