Approve the Cookies
This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies. Read More.
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 31 Dec 2012 (Monday) 11:02
Search threadPrev/next
sponsored links
(this ad will go away when you log in as a registered member)

Confusing Custom Function on 7D

 
RPCrowe
Cream of the Crop
Avatar
7,767 posts
Likes: 521
Joined Nov 2005
Location: San Diego County, California, USA
     
Dec 31, 2012 11:02 |  #1

I am somewhat confused with the 7D Custom Function III-02 (AI Servo 1st/2nd image priority.

It has to do with how autofocus prioritizes Focus/Shutter release in continuous shooting. It allows the photographer to specify what takes precedence when the shutter release button is pressed all the way down.

The choices are:
0: AF Priority/Tracking Priority
1: AF priority/Drive Speed Priority
2. Release/Drive Speed Priority
3. Release Tracking Priority

I cannot understand what happens in choices 0-3 or under what circumstances I would wish to switch the priorities...


See my images at http://rpcrowe.smugmug​.com/ (external link)

  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)
mainbyte
Senior Member
Avatar
332 posts
Gallery: 1 photo
Likes: 22
Joined Mar 2011
Location: Southern Indiana
     
Dec 31, 2012 11:30 |  #2

Here is a bit of a description of what each setting is for and why you may wish to change it. This is described on page 4 of this technical paper. In fact the whole article is helpful for custom settings.

http://cpn.canon-europe.com …om_functions_ex​plained.do (external link)

Ron


Canon 6D | Canon 7DII | 17-40 f/4L | 24-105 f/4L | 70-300 4/5.6L |100mm f/2.8L macro | 50mm 1.4 | 580exII | 2 - 430exII |

  
  LOG IN TO REPLY
vorlon1
Goldmember
Avatar
1,180 posts
Likes: 332
Joined Nov 2011
Location: Miami, Fl.
     
Dec 31, 2012 11:41 |  #3

Excellent article.

"C.Fn III -2 – AI Servo first/second image priority

For AI Servo shooting, you can adjust the priority for the first shot or the second and subsequent shots. It deals with two issues:

How quickly the camera will fire if you suddenly press the shutter button fully.
If the shutter button is held down for continuous shooting, whether AI Servo AF will always take time to ensure correct focus for each shot (which may result in slowing down the drive speed), or whether the camera will always fire at top fps speed (even if proper focus cannot be ensured for each shot in the sequence).

There are four settings:

0: AF priority/Tracking priority – this will give more time to achieve focus before releasing the shutter and then during continuous shooting, focus tracking will be given time to keep accurate focus.
1: AF Priority/Drive speed priority – like setting 0, the first shot will prioritise focusing. However, after that the camera will try to maintain the maximum shooting speed. This is useful if the subject is large and easy to focus on, or not moving over great distances.
2: Release/Drive speed priority – this will fire the shutter as quickly as possible for the first shot, not giving as much time to finding focus. For subsequent shots, the camera will continue to fire at the maximum frame rate in preference to giving time to focus driving. If you have to capture the moment at all costs, this is a good option to use.
3: Release/Tracking priority – this will work like option 2, in that priority is given to releasing the shutter, but for second and subsequent images, the camera will then pass priority to focus tracking, rather than trying to maintain the maximum frame rate."


"We don't see things as they are, we see them as we are." -- Anais Nin
5Dc Gripped, 6D Gripped, Nikon D300, Olympus OMD-EM1, Fuji XT-20, Pentax 50 1.4, 40mm f/2.8 Pancake, 24-105 mm L, 85mm 1.8, 18-200mm 3.5-5.6, Tamron 24-70mm f/2.8, Tamron 60mm f/2 Macro, 70-200mm f/4 L, etc.
Smugmug: http://paladinphotos.s​mugmug.com/ (external link)

  
  LOG IN TO REPLY
MikeWa
Senior Member
Avatar
878 posts
Gallery: 89 photos
Likes: 234
Joined Apr 2012
Location: Seattle Washington
     
Jan 01, 2013 09:32 |  #4

Pushing the shutter release button half way energizes Auto Focus and Image Stabilization in the lens. But what happens when you push the shutter release button all the way down? You would think the shutter would just release. But actually you have choices on what occurs both for the first photo in a burst and for subsequent photos. Your choices are
First picture / Subsequent pictures
1 Check focus release shutter / track focus release shutter
2 Check focus release shutter / release shutter
3 Release shutter / release shutter
4 Release shutter / track focus release shutter
So what is more important to you? Double checking focus or instantly releasing the shutter?

Mike


Mike...G9; 7D; 7D Mark II; EF-S 10-22mm; EF-S 18-135mm IS STM; EF 28-300mm F3.5-5.6L; EF 70-300mm IS USM; EF 70-200mm F2.8L IS-II; EF 100-400mm f4.5-5.6L IS; EXT 1.4-II & 2.0-III; The more I learn the less I know.

  
  LOG IN TO REPLY
The ­ "Canon ­ 7D" ­ Kid
Member
Avatar
111 posts
Likes: 1
Joined Dec 2010
     
Jan 01, 2013 09:51 as a reply to  @ MikeWa's post |  #5

I hope this may be of help also
http://www.deepgreenph​otography.com …ing-up-your-new-canon-7d/ (external link)


Canon 5D Mark III (Gripped), Canon 7D (Gripped), 70-200mm 1:2.8 L IS II USM, 24-105 L, 28-135mm, 75-300mm, 50mm 1.8, 580 EXII, Canon ST-E3-RT, Canon 600EX-RT X's 3 And not nearly enough time/good weather to enjoy it.

  
  LOG IN TO REPLY
convergent
Goldmember
Avatar
2,211 posts
Gallery: 34 photos
Likes: 8
Joined Jan 2006
Location: Raleigh, NC
     
Jan 01, 2013 09:55 |  #6

RPCrowe wrote in post #15427473 (external link)
I cannot understand what happens in choices 0-3 or under what circumstances I would wish to switch the priorities...

The best way to describe, to me, is to give an example. Say you are shooting a basketball game. A lot is happening and you see a fight break out and a player punches another player in the face. You pull the camera up to shoot and hit the button (AI-Servo). Do you want it to take the picture immediately when the button is pressed, or do you want it to delay the shutter release until it is absolutely confirmed in sharp focus. If you go with shutter priority, you may get the peak action of the guy's fist in contact with the face, but it may not be sharply in focus. If you go with focus priority, you may get a sharply focused image of a split second after the guy was hit.

There are various different scenarios with this, but the gist of it is what I described. And you get to choose to have the first shot in a burst be treated differently from the rest. Personally, I have always opted for focus priority because a slightly blurry picture of something is not that interesting to me.


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
apersson850
Cream of the Crop
Avatar
11,761 posts
Likes: 186
Joined Nov 2007
Location: Traryd, Sweden
     
Jan 01, 2013 13:34 |  #7

vorlon1 wrote in post #15427609 (external link)
If the shutter button is held down for continuous shooting, whether AI Servo AF will always take time to ensure correct focus for each shot (which may result in slowing down the drive speed), or whether the camera will always fire at top fps speed (even if proper focus cannot be ensured for each shot in the sequence).

This isn't 100% true.
In release priority, the camera will make one focus measurement, evaluation and lens drive cycle, and that's it. If the subject is an easy target, this will be enough, the image taken will be in focus and the drive speed will be maintained, as there is time allocated for this focusing operation in between the shots.
If the subject is difficult, the camera may drive the lens to the wrong distance setting, or fail to drive the lens at all, if the camera is utterly confused. The image will be out of focus, but it will still be taken, at the claimed frame rate.
This is exactly as described in the quote. However, when set to AF priority, the camera will make one or more attempts at measuring, evaluating and driving the lens to achieve proper focus. Exactly how many Canon does not disclose. But the important thing to understand is that this is a finite number. After a couple of attempts, which will take enough time to slow down the frame rate, the picture will be taken, regardless of if focusing still has not been accomplished successfully.

Thus when using Servo AF, there's no setting which will ensure that every image is properly focused. It's only when using One Shot AF a 7D will refuse to take a picture if it's out of focus. If the picture is taken, the camera is convinced it's focused. It may have focused on something else than what you intended it to, or it may be completely fooled and not focused at all, but at least it thinks the image is in focus.


Anders

  
  LOG IN TO REPLY
vorlon1
Goldmember
Avatar
1,180 posts
Likes: 332
Joined Nov 2011
Location: Miami, Fl.
     
Jan 01, 2013 14:06 |  #8

Well. that's interesting, because I just copied that whole post from the relevant part of the canon article referenced. I should have put quotation marks around the whole thing. Now done.


"We don't see things as they are, we see them as we are." -- Anais Nin
5Dc Gripped, 6D Gripped, Nikon D300, Olympus OMD-EM1, Fuji XT-20, Pentax 50 1.4, 40mm f/2.8 Pancake, 24-105 mm L, 85mm 1.8, 18-200mm 3.5-5.6, Tamron 24-70mm f/2.8, Tamron 60mm f/2 Macro, 70-200mm f/4 L, etc.
Smugmug: http://paladinphotos.s​mugmug.com/ (external link)

  
  LOG IN TO REPLY
apersson850
Cream of the Crop
Avatar
11,761 posts
Likes: 186
Joined Nov 2007
Location: Traryd, Sweden
     
Jan 01, 2013 15:25 as a reply to  @ vorlon1's post |  #9

Seems they didn't go into every detail. The quote is correct to a certain degree, just skips mentioning that the camera will fire even if focus can't be accomplished, even in AF priority.


Anders

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

1,969 views & 0 likes for this thread
Confusing Custom Function on 7D
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?
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 2.0forum software
version 2.0 /
code and design
by Pekka Saarinen ©
for photography-on-the.net

Latest registered member is Nidge
642 guests, 416 members online
Simultaneous users record so far is 6430, that happened on Dec 03, 2017

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.