Reading mode: Light Dark

AF-ON dedicated button ?

Go to last post
lmpmd said:
IMHO with af-c it's great. Your at a public event and you want 6 fps
of a person, but you don't want person in center of picture. Hard to
do with focus on shutter release and set to center. You have to
refocus and recompose over and over. Just focus with thumb on af-on
and take you finger off af-on , recompose and take 6 fps. I think
when you don't want to take rapid pics (not use af-c) you can go back
to putting focus on the shutter release. But I'm thinking switching
methods gets confusing and I may just leave focus on the af-on button
for good. Appreciate any advice from others.
--
Larry
Click to expand...
Why would you want 6fps of someone who isn't moving? If they move then they will be out of focus. Put the focus point over the subject, then the camera can track them and the metering will give them priority. The Af-on button was king when there was one focus point 51 AF points is a big selling point for the D300 that redundant thumb can keep the focus point on the subject. If for some reason you don't want the camera to refocus click to manual or on the long lenses use the focus lock button.
 
From reading previous comments on this forum, I made the switch about a year ago. My usage may change a bit after some of the ideas in this thread (via the "wise man"!) but the reason I made the switch is this.

I can now set the focus on one region of space, using AF ON, and independently set exposure on some other region, with a shutter half-press, then aim in yet a third region for the shot. For the more basic 70% of shots, where the camera is pointed in one direction for all these operations, the only additional complication is remembering to depress the AF ON button. This becomes second nature after a week or so.

--
Byrne
 
You can :
  • At first lock AF with AF-ON button (press and release)
  • and also lock exposure with the second button AE-L/AF-L (press and release)
  • before recompose and press the shutter release.
 
Settings :
A5 AF Activation : Button AF-ON (only)
A1 AF-C : Release

Nothing else.

Your button AF-ON will be OK for the both position C or S . (But C is better).

Just press and hold the button AF-ON until AF is OK then release that button .
 
zenfr9 said:
Settings :
A5 AF Activation : Button AF-ON (only)
A1 AF-C : Release

Nothing else.

Your button AF-ON will be OK for the both position C or S . (But C is
better).

Just press and hold the button AF-ON until AF is OK then release that
button .
Click to expand...
But when using C mode then you do your focus on subject with AF-ON (subject is moving) and hold it. Camera will follow the subject and then you can do a shutter release when you want it to do.

Am I right?

What is the difference because if you do a focus on subject with shutter release button and have in C mode...if the camera will still follow the subject and try to focus it??
 
zenfr9 said:
You can :
  • At first lock AF with AF-ON button (press and release)
  • and also lock exposure with the second button AE-L/AF-L (press and
release)
  • before recompose and press the shutter release.
Click to expand...
Yep, that's how I use it as well.

Here's how I use the Shutter Release and AF-ON buttons.

Shutter button: Focus and exposure lock.
AF-ON button: Focus lock only.

For many of my photos, I just use the Shutter button.

If I want to focus and recompose, I use the AF-ON button to focus on the subject. Then I recompose while my thumb is still on the AF-ON button. Since it doesn't activate Exposure Lock, the exposure/metering will change. They are independent of each other.

If I half-pressed the shutter to focus and recompose, both the focus and exposure would be locked. I don't like the exposure being locked at the same time as my focus. What if my recomposed shot has fairly different light than the light available when focusing? The exposure is free to change.

If I use spot meter, I never use the Shutter button because, again, it locks both the focus and exposure. Using spot metering, I focus and "lock focus" by holding the AF-ON button, and then point the camera's spot meter at something else and lock the exposure individually. After locking both of these indivudually, I recompose and use the Shutter button to shoot. :)

The only difference between what the "wise man" said and what I do is that I need to hold the AF-ON button to focus and recompose, since the shutter button still focuses. If I hold the AF-ON button and Shutter button, the focus locked using the AF-On button takes precedent.
 
cayshi said:
What is the difference because if you do a focus on subject with
shutter release button and have in C mode...if the camera will still
follow the subject and try to focus it??
Click to expand...
In AF-C you may want to take rapid pictures without worrying if center point is or isn't on the subject. You can do this by removing you finger from the af-on button, and focus is not going to change. If you have focus on the shutter release button, you focus may change to some undesirable distance, if the center point in not right on the subject.

--
Larry
 
wait, so when decoupling the focus from the shutter to the AF-on button only, the VR activation still remain with the shutter?

So is this correct:
1) Press AF-On to focus, release AF-On to lock
2) Recompose
3) Half-press Shutter to let VR kick in
4) Full press Shutter to take the shot
 
I just recently been trying the AF-On only method, and I found that when shooting from the hip or off-the-eyes low angle shoot it's more convenient to have the thumb on the shutter to half-press and full-press, rather than operate the focus and release with both thumb and index finger.
Other than that the use of AF-On is pretty good and very easy to get used to.
 
I've always wondered why there was a separate af-on button so this thread has been quite educational. After trying it for a few days though, I think that my mind and my finger are just too used to the half-press method.

... use the ae-lock for metering; half press to focus lock; press all the way for the photo....

I guess just different strokes for different folks... I'll keep playing with it though.
--
http://www.flickr.com/photos/22902194@N00/
 
lmpmd said:
lmpmd said:
What is the difference because if you do a focus on subject with
shutter release button and have in C mode...if the camera will still
follow the subject and try to focus it??
Click to expand...
In AF-C you may want to take rapid pictures without worrying if
center point is or isn't on the subject. You can do this by removing
you finger from the af-on button, and focus is not going to change.
If you have focus on the shutter release button, you focus may change
to some undesirable distance, if the center point in not right on
the subject.

--
Larry
Click to expand...
So you are saying that if I have set that camera focus with pressing AF-on button in AF-C mode it is enought that I choice focus and press AF-on button only once and camera will follow the subject which I focused? Then I only have to use shutter release button??

Thanks!
 
In C mode:
  • if you want to lock the focus : press the AF-ON a few seconds then release it to lock your AF, recompose and shoot at the same AF, as many time as you like.
  • If you still want tracking, because your subject is moving around, you must keep your finger on that AF-ON button and shoot at the right moment !!!
Hope that could help.

PS : I love my D300 so much !!!!
 
zenfr9 said:
In C mode:
  • if you want to lock the focus : press the AF-ON a few seconds then
release it to lock your AF, recompose and shoot at the same AF, as
many time as you like.
  • If you still want tracking, because your subject is moving around,
you must keep your finger on that AF-ON button and shoot at the right
moment !!!

Hope that could help.
Click to expand...
How do I change focus points as I am doing that?
 
Leave focus on center point. Focus on cheerleaders face. Take finger of af-on button. Then when she's jumping up and down, you can frame pic and she doesn't have to be in the center. Cause focus locks when you take finger off. Otherwise there's no way to do it in af-c. If you push on shutter release it refocuses on something in the distance that you dont want to be infocus.
--
Larry
 
lmpmd said:
Leave focus on center point. Focus on cheerleaders face. Take
finger of af-on button. Then when she's jumping up and down, you can
frame pic and she doesn't have to be in the center. Cause focus
locks when you take finger off. Otherwise there's no way to do it in
af-c. If you push on shutter release it refocuses on something in
the distance that you dont want to be infocus.
--
Larry
Click to expand...
so again...

if object is in the same position it is enought that you only push AF-on and released it and then you can take a picture with shutter release.

if subject moving and jumping then you have to hold AF-on button and in the same time taking a picture with shutter release.

But in which situation it is good to use AE/AL , AF-on and shutter release separate?

If you have static object it is easy that you lock AE and AF and then do a recomposition, because you want that yout subject is perfectly exposed and in focus.

What do you usually use? AE lock on half press shutter release or AE lock with AE/AF button? And there is a third option that you leave AE as camera meters when you move camera from the subject.

Why? In which situations?
 
Again in AF-C it is wokring this way (you can release the AF-ON button after aquiring focus), with D200, D300 and D3.

However in AF-S the focus point is changing as soon as you realease the AF-ON button press the shutter button, it is re-focussing

You have to keep the AF-ON button pressed to lock focus

It might be that I have some settings changed.
Michel
zenfr9 said:
A5 AF Activation : Button AF-ON (only)
A1 AF-C : Release

Nothing else.

Your button AF-ON will be OK for the both position C or S . (But C is
better).

Just press and hold the button AF-ON until AF is OK then release that
button .
Click to expand...
--
~ Light is eveything ~
http://www.fotopropaganda.com
http://www.pbase.com/photopropaganda
 
One caveat with leaving the setting in AF-C (continuous) is that with the SB800 or SB600 flash mounted, the flashes auto focus assist doesn't come on while in AF-C. If you want that assist, just switch back to AF-S to get that feature.
 
You must log in or register to reply here.

Keyboard shortcuts

f
Forum
m
My threads
Mobile site
About
Editorial content
Cameras & Lenses
Community
All content, design, and layout are Copyright © 1998–2025 Digital Photography Review All Rights Reserved.
Reproduction in whole or part in any form or medium without specific written permission is prohibited.
When you use DPReview links to buy products, the site may earn a commission.
©GPS Media - Guides, Products, Services.
Back
Top