Approve the Cookies
This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and our Privacy Policy.
OK
Index  •   • New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Guest
New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Register to forums    Log in

 
FORUMS Canon Cameras, Lenses & Accessories Canon EOS Digital Cameras 
Thread started 05 Oct 2014 (Sunday) 11:35
Search threadPrev/next
sponsored links
(this ad will go away when you log in as a registered member)

Back Button Focusing 5D3 Issue?

 
SierraHighPhoto
Senior Member
Avatar
447 posts
Likes: 21
Joined Mar 2008
Location: California
     
Oct 05, 2014 11:35 |  #1

Hey everyone,

I'm not sure if I'm making an error, as I just switched to back button focusing, as all I've heard is positive things, or if something is setup wrong with my camera.

As far as the focusing goes, it does focus with the back button "AF-ON." The issue I'm having is where is focuses? I guess that's the best way to say it.

I use the "Expand AF area" as I've heard that's good for sports photography and others. I set it up to the middle right side or left, depending on where I am at, yet when I press the back button to focus, it then focuses center.

So for instance If I have a football player running down the field and have the focus points on him (Expand AF area), and click the back button focus, it will focus on whatever is in the middle of the frame. Whether it be another player, the sideline, etc.

Am I doing something wrong? Isn't it supposed to be focusing where the "Expand AF area" is? Not the center?

Just in case I'm explaining it wrong or not making it clear. In my viewfinder I have the setup like this:

PHOTOBUCKET EMBEDDING IS DISABLED BY THIS MEMBER.
Photobucket sends ads instead of embedding photos from their free galleries.
Click the link (if available) below to see the image in a gallery page.

http://i283.photobucke​t.com …ography/1_zps30​1f0cd0.jpg (external link)


But once I click the back button focus, to focus whatever the focus points are on, it goes to this:

PHOTOBUCKET EMBEDDING IS DISABLED BY THIS MEMBER.
Photobucket sends ads instead of embedding photos from their free galleries.
Click the link (if available) below to see the image in a gallery page.

http://i283.photobucke​t.com …ography/2_zps3c​9261ee.jpg (external link)


  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)
amfoto1
Cream of the Crop
10,251 posts
Likes: 83
Joined Aug 2007
Location: San Jose, California
     
Oct 05, 2014 12:05 |  #2

There is something wrong... most likely with your settings, but possibly with your camera. The camera should not default back to the center point (with expansion) when AF is started.

It should start focus with the pre-selected point at the center of the Expansion Points, wherever you have set that.

Here's the difference between Zone Focus and Expansion Point Focus.

Expansion Point Focus always starts at the selected center point within the Expansion, then allows the adjacent points to take over if the subject moves to one of them. But it should not always revert to the center point of the entire AF array.

Your camera has two Expansion Point Focus modes: 4-point and 8-point. The 4-point mode allows expansion to the first point right or left, above or below your selected "starting" point. 8-point allows expansion to all eight points surrounding your selected "starting" point, including the four on the diagonal from the starting point in addition to the same four that 4-point mode allows.

Zone Focus, on the other hand, is like a scaled down version of All Points, and focus can start with any of the active AF points within the selected Zone. The camera will usually first choose to focus on what's closest and covered by any of the AF points in the Zone (all other factors being equal).

Expansion is potentially more accurate, leaves less up to chance that the camera might focus on the wrong thing, but you do have to start with the center point.

Actually Single Point (no Expansion), manually selected, is still the most accurate. But when using it, it's down to you to put the AF point right where you want the camera to focus, and keep it there even when the subject is moving. So long as you do that, there's much less chance the camera will focus somewhere else.

If I were you, I'd try Single Point and see if the camera again defaults back to the center point AF point. Also try the other Expansion Point mode (8 points around the selected one, instead of 4 points).

It shouldn't matter whether you are using BBF or not, for any of the above. BBF does put you more in control of AF, but really shouldn't directly effect any of the above. But, just to be sure I'd also try your setup exactly the same except without BBF, to see if it acts the same way when the AF is started with half-press of the shutter release button. You also might try swapping the AF-On and * (AE-Lock) button functions, to see if that makes a difference. The camera should behave the same way in all cases. If not, something is wrong.

Next check to see if you have Orientation Linked AF enabled in your custom functions. I've found that if this particular CFn is on, but you haven't followed through and programmed the camera to use certain points and point-patterns in all three possible orientations, the AF system sometimes does strange stuff. Mostly it acts strangely when you change orientation... but I think I've noticed it cause other strange effects on my cameras, too (7D, not 5DIII... but it's similar).

Also check if you have set a "home" AF point (most likely the center one). Usually that's recalled by pressing the joystick (rather than tilting it) or using a recall button that's on some of the super tele lenses... But, who knows, maybe it's causing a glitch.

If you can't find anything in your settings, you might try resetting them to the defaults, or by fully rebooting the camera by pulling all the batteries (and pressing the shutter release button once to discharge any remaining power), or even by completely reinstalling the firmware. These things can "clear" fragments of misinformation that's gotten "stuck" in the camera's memory. If this sounds like dealing with computer problems, that's because it is. Today's DSLRs are as much computers, as they are cameras.

Hope this helps.


Alan Myers (external link) "Walk softly and carry a big lens."
5DII, 7DII(x2), 7D(x2) & other cameras. 10-22mm, Tokina 12-24/4, 20/2.8, TS 24/3.5L, 24-70/2.8L, 28/1.8, 28-135 IS (x2), TS 45/2.8, 50/1.4, Tamron 60/2.0, 70-200/4L IS, 70-200/2.8 IS, 85/1.8, Tamron 90/2.5 Macro, 100/2.8 USM, 100-400L II, 135/2L, 180/3.5L, 300/4L IS (x2), 300/2.8L IS, 500/4L IS, EF 1.4X II, EF 2X II. Flashes, studio strobes & various access. - FLICKR (external link) - ZENFOLIO (external link)

  
  LOG IN TO REPLY
Talley
Talley Whacker
Avatar
11,080 posts
Gallery: 45 photos
Likes: 2746
Joined Dec 2011
Location: Houston
     
Oct 05, 2014 12:38 |  #3

did you set the shutter button to meter only? if you didn't then it will do just as you described. for back button focusing you have to turn on the focus to the AFON button and then change shutter to metering only


A7rIII | A7III | 12-24 F4 | 16-35 GM | 28-75 2.8 | 100-400 GM | 12mm 2.8 Fisheye | 35mm 2.8 | 85mm 1.8 | 35A | 85A | 200mm L F2 IS | MC-11
My Gear Archive

  
  LOG IN TO REPLY
convergent
Goldmember
Avatar
2,211 posts
Gallery: 34 photos
Likes: 9
Joined Jan 2006
Location: Raleigh, NC
     
Oct 05, 2014 13:43 |  #4

Talley wrote in post #17195069 (external link)
did you set the shutter button to meter only? if you didn't then it will do just as you described. for back button focusing you have to turn on the focus to the AFON button and then change shutter to metering only

Agree that this may be the problem. I leave back button on AFON all the time, and just turn the shutter half press on and off for it... usually when I'm handing the camera to a friend to take a pic and don't feel like explaining the back button.


Mike - Victory Photo (external link) | Full Gear List | Feedback
5D3 gripped - 7D2 gripped - 17-40L f/4 - 18-135 f/3.5-5.6 IS STM - 24-70L f/2.8 II - 70-200L f/2.8 IS II - 100-400 L f/4.6-5.6 IS II
135L f/2 - 300L f/2.8 IS - Siggy 15 f/2.8 Fisheye, 100 f/2.8 Macro - TC1.4 II - TC2 III - (2) 600EX-RT - ST-E3-RT

  
  LOG IN TO REPLY
SierraHighPhoto
THREAD ­ STARTER
Senior Member
Avatar
447 posts
Likes: 21
Joined Mar 2008
Location: California
     
Oct 05, 2014 14:25 as a reply to  @ convergent's post |  #5

Thanks for the info guys. I had the metering mode set right and everything. I think it was just what button I was using. I changed the focusing to the AE Lock button rather than the AF-ON and it works just like it's supposed to.

Thanks again



  
  LOG IN TO REPLY
oldvultureface
Goldmember
Avatar
4,244 posts
Gallery: 72 photos
Best ofs: 2
Likes: 272
Joined Jun 2008
Location: Northwest Indiana USA
     
Oct 05, 2014 14:44 |  #6

You may have inadvertently registered an AF point and assigned that to your AF-ON button, page 324 and following in your manual.




  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)

1,123 views & 0 likes for this thread
Back Button Focusing 5D3 Issue?
FORUMS Canon Cameras, Lenses & Accessories Canon EOS Digital Cameras 
AAA
x 1600
y 1600

Jump to forum...   •  Rules   •  Index   •  New posts   •  RTAT   •  'Best of'   •  Gallery   •  Gear   •  Reviews   •  Member list   •  Polls   •  Image rules   •  Search   •  Password reset

Not a member yet?
Register to forums
Registered members may log in to forums and access all the features: full search, image upload, follow forums, own gear list and ratings, likes, more forums, private messaging, thread follow, notifications, own gallery, all settings, view hosted photos, own reviews, see more and do more... and all is free. Don't be a stranger - register now and start posting!


COOKIES DISCLAIMER: This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and to our privacy policy.
Privacy policy and cookie usage info.


POWERED BY AMASS forum software 2.1forum software
version 2.1 /
code and design
by Pekka Saarinen ©
for photography-on-the.net

Latest registered member is masoudyas
874 guests, 316 members online
Simultaneous users record so far is 15144, that happened on Nov 22, 2018

Photography-on-the.net Digital Photography Forums is the website for photographers and all who love great photos, camera and post processing techniques, gear talk, discussion and sharing. Professionals, hobbyists, newbies and those who don't even own a camera -- all are welcome regardless of skill, favourite brand, gear, gender or age. Registering and usage is free.