p.2 #1 · I have a question about back-button focusing
alohadave wrote:
Pentax is the same way. I don't see it as a problem though. You have to have the shutter button half-pressed for about 1/2 second to activate the SR. IMO, it's not really part of the focusing system.
We'll have to agree to disagree. I think it IS a problem (see what I did there? )
I honestly don't see where one would switch their camera from shutter-focusing to back-button focusing with part of their goal being to NOT engage VR.
Moreover I dunno about Nikon but Canon goes to great lengths to explain that they prefer lens IS over body IS in good part because lens IS stabilizes the VIEWFINDER as well as the actual photo. I would think that stabilizing the lens during AF should result in more accurate AF... that should make intuitive sense, no?
Bottom line... I have $20 right here that says that if you put 100 Nikon shooters in a room who use back button focusing and shoot the 70-200 VR or another VR lens you will likely find that quite a few of them don't KNOW that using back-button-focusing means they still need to half-press the shutter if they want VR, most would probably not be able to come up with a (reasonable) scenario where you'd want to HAVE TO use back-button PLUS half-press to get VR, and I'm not convinced you'd find ONE person in the room who prefers that VR not be engaged when they BBF. Ergo... if nothing else, Nikon should have made this something you can customize.
p.2 #2 · I have a question about back-button focusing
cas5 wrote:
Wow... I didn't know about VR not engaging if you BBF. Will it engage when you trip the shutter?
My understanding is that yes it will... however my understanding is that if you really want the full performance of VR you should half-press the shutter before taking the shot... which I certainly don't do.
Frankly this is probably my biggest disappointment with my Nikon gear. I find it unexplicable, unjustifiable, and in light of the in some cases nearly ridiculous attention to detail in terms of customizing the camera... I can't believe there isn't a custom function to get around this.
p.2 #3 · I have a question about back-button focusing
Ok, a further bit of clarification...
I don't really know if Nikon's approach is in fact a problem or not in terms of "will the VR do it's job"
I've read articles that suggest that Nikon's system does not in fact require the VR to engage prior to shutter release, and that in fact once you trip the shutter the VR "resets" the lens to a centered position and then does it's thing... whereas the operation it does during the half-press is more centered around the goal of giving a perception of stability to the user, presumably with the goal to help the photographer attain a steadier stance.
Hum... maybe I should do one of those VR tests... you know... shoot a clock with VR off, with VR on but using BBF with no shutter half press... and with VR on with BBF + shutter half press.
p.2 #4 · I have a question about back-button focusing
I called Nikon support and got a link to this article.
The only think that seems really worth repeating is, "Nikon developed an algorithm exclusively used during half-pressing of the shutter release button. The algorithm controls blur correction by steps and at a slightly weaker level than usual.
When the shutter release button is fully pressed, a different algorithm is employed, so that the blur-correction effect is maximized during exposure, providing clear images." So, it would seem that on a full press of the shutter, the VR system is engaged. At the very least, BBF does not appear to stabilize the image for the autofocus system and viewfinder. I've got a call into NPS for further clarification.
p.2 #7 · I have a question about back-button focusing
back button focus is the only way to go....
a good example ... the processional: bride walking down the isle with dad...
setup ai-servo.
your at end of isle down front.
they start walking in and you lock on with back button.
Now you can choose when to fire the shutter without messing up the focus....
p.2 #8 · I have a question about back-button focusing
Ziffl3 wrote:
back button focus is the only way to go....
a good example ... the processional: bride walking down the isle with dad...
setup ai-servo.
your at end of isle down front.
they start walking in and you lock on with back button.
Now you can choose when to fire the shutter without messing up the focus....
Not really sure how your example extolls the benefit of BBF. In that same scenario with SBF I'm not sure why you'd mess up the focus.
p.2 #9 · I have a question about back-button focusing
cas5 wrote:
I called Nikon support and got a link to this article.
The only think that seems really worth repeating is, "Nikon developed an algorithm exclusively used during half-pressing of the shutter release button. The algorithm controls blur correction by steps and at a slightly weaker level than usual.
When the shutter release button is fully pressed, a different algorithm is employed, so that the blur-correction effect is maximized during exposure, providing clear images." So, it would seem that on a full press of the shutter, the VR system is engaged. At the very least, BBF does not appear to stabilize the image for the autofocus system and viewfinder. I've got a call into NPS for further clarification....Show more →
Actually this bit here is pretty telling
"In-the-lens corrections provide not only blur-corrected images of approx. 3 - 4 stops' worth of camera-shake compensation, but also clearer finder images, quicker AF, and higher precision metering."
If it's true that VR provides FASTER AF, then it must be true that VR not being engaged results in SLOWER AF... which quite frankly is just totally logical considering that the Phase detect is looking for contrast and contrasty stuff that is shaking (due to camera shake) isn't as contrasty as stationary contrasty stuff.
Let me know what NPS comes back with but I might have to spend some time working on a two-finger technique when shooting the 70-200
p.2 #14 · I have a question about back-button focusing
duet wrote:
What would you say advantages of BBF over half shutter lock then recompose?
Taking a couple shots of something off center in the frame means that you focus once on your subject, recompose and fire off as many shots as you need without needing to recompose for every shot.
Have you ever seen someone shooting and they keep tilting or swinging the camera? They are refocusing on every shot.
p.2 #15 · I have a question about back-button focusing
alohadave wrote:
Taking a couple shots of something off center in the frame means that you focus once on your subject, recompose and fire off as many shots as you need without needing to recompose for every shot.
Have you ever seen someone shooting and they keep tilting or swinging the camera? They are refocusing on every shot.
Well you can do that with half-pressing the shutter then recompose... and if you dont let go of your finger all the way then if you shoot continuously without re-focusing again.
p.2 #16 · I have a question about back-button focusing
lisy78 wrote:
Not really sure how your example extolls the benefit of BBF. In that same scenario with SBF I'm not sure why you'd mess up the focus.
well you can move your frame around and the subject will stay AF locked.... as long as you don't move completely out of you AF area.
now it is just about composition and the shutter button.
works better on the exit when the couple is practically trying to run out of the ceremony!
p.2 #17 · I have a question about back-button focusing
duet wrote:
Well you can do that with half-pressing the shutter then recompose... and if you dont let go of your finger all the way then if you shoot continuously without re-focusing again.
The point is that you don't have to keep shooting. And when you stop, you don't have to refocus. Make sense?
p.2 #18 · I have a question about back-button focusing
Inku Yo wrote:
The point is that you don't have to keep shooting. And when you stop, you don't have to refocus. Make sense?
inku, i understand that. What im trying to say is that even using half-pressing shutter method, you don't have to re-focus if you just let go your shutter half way. so you can half press shutter, lock the focus recompose, press shutter fully to take a picture, let go half way then recompose, then shoot again. get it?
p.2 #19 · I have a question about back-button focusing
duet wrote:
inku, i understand that. What im trying to say is that even using half-pressing shutter method, you don't have to re-focus if you just let go your shutter half way. so you can half press shutter, lock the focus recompose, press shutter fully to take a picture, let go half way then recompose, then shoot again. get it?
I get it. I used to do that all the time... and I've missed moments while I was recomposing the second, third, etc... time.
Next time try this... focus, recompose, shoot... put your camera down to your side... put your camera up to your eye, focus, recompose, shoot...using the half press method and try to keep the shutter button pressed only half way. As opposed to put your camera up to your eye and shoot... using the back button method.
p.2 #20 · I have a question about back-button focusing
Inku Yo wrote:
Next time try this... focus, recompose, shoot... put your camera down to your side... put your camera up to your eye, focus, recompose, shoot...using the half press method and try to keep the shutter button pressed only half way. As opposed to put your camera up to your eye and shoot... using the back button method.
Honestly, I don't understand what you just said here. Sorry
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