Even though we ARE Nikon lovers,we are NOT affiliated with Nikon Corp. in any way.

English German French

Sign up Login
Home Forums Articles Galleries Recent Photos Contest Help Search News Workshops Shop Upgrade Membership Recommended
members
All members Wiki Contests Vouchers Apps Newsletter THE NIKONIAN™ Magazines Podcasts Fundraising

Wide-area AF assist

Gray_star

US
52 posts

Click to send email to this author Click to send private message to this author

"RE: Wide-area AF assist"

Gray_star Registered since 17th Dec 2012
Wed 26-Dec-12 05:45 AM

AF-S/C/A - HOW to focus.
AF-S - Focus just once.
AF-C - Focus continuously.
AF-A - Starts as AF-S and if the distance to subject changes, switches to AF-C.

AF-Area - WHERE to focus.
Single Point - Focus at the selected focus point only.
Dynamic - Start at the selected focus point. When a subject is identified, keep focus on the subject even if the subject moves to surrounding focus points. Exposure is always based on the original selected focus point only.
3D-Tracking - Start at the selected focus point. When a subject is identified, keep focus on the subject even if the subject moves to surrounding focus points. When the subject moves, the new focus point becomes the "selected" focus point. Exposure is based on the new focus point.
Auto - the camera selects the focus point.

With AF-S, all AF-Area modes act like the Single Point AF-Area. In fact, on the D7000 I don't think you can even select any other AF-Area.


In AF-A mode, the SB-600 will not provide AF-Assist for continued focusing if the camera switches to AF-C. As I had stated above, in AF-A mode, my D90 wouldn't even switch to AF-C mode when the SB-600 is mounted. I don't know if that is true with a D7000. In any case, AF-Assist never works with AF-C (whether it's AF-C mode or AF-A in AF-C mode.)

If you want to maintain focus with AF-Assist then you cannot use AF-C. You should use AF-S and "drum" the shutter (continuously half-pressing and releasing the shutter.) When you want to take the picture, press the shutter fully...don't stop at the half-press, as there's no need (however, make sure that your custom setting "a2:AF-S Priority" is set to "Focus"...you want the camera to fire after it has achieved a focus lock.)

This will also place red lights from the SB-600 on the subject every time you half-press.

Yes, in 3D Tracking the focus point actually moves with the subject. In Dynamic the focus point does not move. The focus points that surround the selected focus point are simply assisting in maintaining focus. The expectation is that you really do want the subject under that one selected focus point. With 3D Tracking, the expectation is that the subject can be anywhere, and so the focus point follows. The difference is composition. Use Dynamic when your composition is fixed and the subject needs to be in the correct spot. Use 3D Tracking when the composition is fluid. 3D Tracking with AF-C is also good for the "focus & recompose" method of composing images. You focus on something in the center of the image, and then recompose. As you recompose, the object you focused on will be tracked, and will be kept in focus. This is necessary when using 35-50mm lenses at large apertures, as the change in composition may blur the object you focused on.

This is a hot, active topic! Wide-area AF assist [View all] , GeorgCantor Silver Member , Fri 21-Dec-12 02:07 AM
Subject
ID
Reply message RE: Wide-area AF assist
1
Reply message RE: Wide-area AF assist
2
     Reply message RE: Wide-area AF assist
3
          Reply message RE: Wide-area AF assist
4
               Reply message RE: Wide-area AF assist
5
               Reply message RE: Wide-area AF assist
6
                    Reply message RE: Wide-area AF assist
7
                         Reply message RE: Wide-area AF assist
8
                         Reply message RE: Wide-area AF assist
10
                         Reply message RE: Wide-area AF assist
9
Reply message RE: Wide-area AF assist
11
Reply message RE: Wide-area AF assist
12
     Reply message RE: Wide-area AF assist
13
          Reply message RE: Wide-area AF assist
14
               Reply message RE: Wide-area AF assist
15
               Reply message RE: Wide-area AF assist
16
                    Reply message RE: Wide-area AF assist
17
                         Reply message RE: Wide-area AF assist
18
                         Reply message RE: Wide-area AF assist
19
                              Reply message RE: Wide-area AF assist
20
                                   Reply message RE: Wide-area AF assist
21
                                        Reply message RE: Wide-area AF assist
22
                                             Reply message RE: Wide-area AF assist
23
                                                  Reply message RE: Wide-area AF assist
24
                                                  Reply message RE: Wide-area AF assist
25
                                                  Reply message RE: Wide-area AF assist
26
                                                  Reply message RE: Wide-area AF assist
27
                                                  Reply message RE: Wide-area AF assist
28
                                                  Reply message RE: Wide-area AF assist
29
                                                  Reply message RE: Wide-area AF assist
30
                                                  Reply message RE: Wide-area AF assist
31
                                                  Reply message RE: Wide-area AF assist
32
                                                  Reply message RE: Wide-area AF assist
33