back button focus

have just read through the thread from the start, did not know the front button & back button [if used] had any thing to do with exposure thought it was a af thing but will stand corrected
 
blue marlin said:
have just read through the thread from the start, did not know the front button & back button [if used] had any thing to do with exposure thought it was a af thing but will stand corrected
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as i understand it ..it is af.. but by default it effects the exposure... exposure is locked when you haf press shutter.. so its set at the start of a players run say.. until you fully press.... but if using back button no exposure is set until you click shutter.. so exposure is set every time you hit shutter.. not at start of the run..

if a player runs full length of pitch and the light changes while he runs.. with back focus you will get the exposure at time of clicking.. with half press you get the exposure from start of run ?

is that right gary?
 
KIPAX said:
as i understand it ..it is af.. but by default it effects the exposure... exposure is locked when you haf press shutter.. so its set at the start of a players run say.. until you fully press.... but if using back button no exposure is set until you click shutter.. so exposure is set every time you hit shutter.. not at start of the run..

if a player runs full length of pitch and the light changes while he runs.. with back focus you will get the exposure at time of clicking.. with half press you get the exposure from start of run ?

is that right gary?
Click to expand...

that makes so much more sense that what everyone else has said in both threads on this
 
KIPAX said:
as i understand it ..it is af.. but by default it effects the exposure... exposure is locked when you haf press shutter.. so its set at the start of a players run say.. until you fully press.... but if using back button no exposure is set until you click shutter.. so exposure is set every time you hit shutter.. not at start of the run..

if a player runs full length of pitch and the light changes while he runs.. with back focus you will get the exposure at time of clicking.. with half press you get the exposure from start of run ?

is that right gary?
Click to expand...

Can't say for certain on the 1d, but on all my Canon bodies (except 300d) the exposure can be set to lock or not on the half press. For motorsport I often have it to meter at point of exposure, for more considered situations (weddings portraits landscape) I use the half press as an ae lock.

slow internet connection means I can't look it up but from memory its a choice between 4.1.0 and 4.1.2
 
Exp doesn't lock by default on Nikon pro bodies.
 
EOS_JD said:
To track you still need to have AI Servo initiated whether back focus or not? The two situations you explain would be the same for either front/back focus. The important issue relates to seperating the exposure from the focus button.
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if you have rear button af, you only need to leave it on afc all the time.
and it will be the same as afs and afc all in one(because you just remove your finger from the rear af button, if you point at a subject and remove your finger the focus will be locked, or you can keep your finger on the af button and it will track the subject.

if you have the af on the shutter button and have it on afc(focus mode) and point at the subject and try lock focus it will, but as soon as you move the camera to try put subject of center the af will adjust its self because of being in afc mode.
so you would have to go in to the menu or flick the af swith on the front of the camera to select afs mode so you can lock focus and move the subject of center.

so with shutter on button you will have to go between afs and afc mode in different situations.
where as rear button af just leave on afc mode and it will give you the same as having afc and afs modes.
 
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KIPAX said:
as i understand it ..it is af.. but by default it effects the exposure... exposure is locked when you haf press shutter.. so its set at the start of a players run say.. until you fully press.... but if using back button no exposure is set until you click shutter.. so exposure is set every time you hit shutter.. not at start of the run..

if a player runs full length of pitch and the light changes while he runs.. with back focus you will get the exposure at time of clicking.. with half press you get the exposure from start of run ?

is that right gary?
Click to expand...
Spot on mate, great for grounds in summer where stands throw shadows and play goes in and out of said shadows
 
Since seeing this thread I've had another look into BBF and have decided to give it a try. If nothing else, it'll save me having to remember to switch the lens to MF once I've focussed and re-composed a landscape shot and want to experiment with different exposures and filters.

Wish I'd done it before my Hitech ND grad went crashing to the ground due to me forgetting to set the lens to MF! :gag: (I was waiting for an adapter ring for the Cokin P holder so just had the filter in the Cokin holder hanging loosely on the end of the lens).
 
just to make sure i understand this:-
if you are using the front button only, the exposure is locked so eg you focus on an object that is coming to wards you [or going away] and you shoot a burst the exposure is determind when you first 1/2 press the shutter ?
that cant work in manual exposure or am i missing the point here.
2nd point what a good thread tony
 
scottthehat said:
if you have rear button af, you only need to leave it on afc all the time.
and it will be the same as afs and afc all in one(because you just remove your finger from the rear af button, if you point at a subject and remove your finger the focus will be locked, or you can keep your finger on the af button and it will track the subject.

if you have the af on the shutter button and have it on afc(focus mode) and point at the subject and try lock focus it will, but as soon as you move the camera to try put subject of center the af will adjust its self because of being in afc mode.
so you would have to go in to the menu or flick the af swith on the front of the camera to select afs mode so you can lock focus and move the subject of center.

so with shutter on button you will have to go between afs and afc mode in different situations.
where as rear button af just leave on afc mode and it will give you the same as having afc and afs modes.
Click to expand...

Except AI Servo is not as accurate as Single shot and that's why I use that. in AI Servo you can take a shot without a confirmation lock I think.
 
EOS_JD said:
Except AI Servo is not as accurate as Single shot and that's why I use that. in AI Servo you can take a shot without a confirmation lock I think.
Click to expand...
maybe just a canon thing, because afc is just as accurate as afs for stationary objects.
and also in afc and afs you can select it to only take a shot if in focus, and also out of focus.
 
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I don't know about Canon bodies but from reading this thread I'd say they were different in this to the way Nikon bodies work. There is a separate back button on my bodies for locking exposure.
 
Phil V said:
Can't say for certain on the 1d, but on all my Canon bodies (except 300d) the exposure can be set to lock or not on the half press. For motorsport I often have it to meter at point of exposure, for more considered situations (weddings portraits landscape) I use the half press as an ae lock.

slow internet connection means I can't look it up but from memory its a choice between 4.1.0 and 4.1.2
Click to expand...

From the 1d manual 4.1 to maintain AE lock on the shutter button half press and 4.3 to have no lock (exposure measured on firing shutter)

scottthehat said:
maybe just a canon thing, because afc is just as accurate as afs for stationary objects.
and also in afc and afs you can select it to only take a shot if in focus, and also out of focus.
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The Canon AF Servo is just as accurate as the one shot - but it won't stop you taking an out of focus picture by itself. However you can tune the Servo focus to prioritise AF or shooting speed in a variety of ways.

awp said:
I don't know about Canon bodies but from reading this thread I'd say they were different in this to the way Nikon bodies work. There is a separate back button on my bodies for locking exposure.
Click to expand...

Nope, the back button that we're talking about on Canon bodies comes out of the factory as the AE lock button. On most Canon bodies this can be switched to control AF, even the newer bodies that have a dedicated AF button on the rear:shrug:
 
i tried the dedicated "af-on" button at the rear of my 1dmkIV yesterday and it fucuses with that...

without me setting anything in camera that is..


i have either a commision to shoot college footy tommorow or i will go to accy v wrexham reserves and give it a try :)
 
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Tony the major difference with how it's set up at the moment, is that the shutter button will over ride the AF-On. By choosing C.FnIV-1-2 you're removing any AF function from the shutter. By leaving it as it is at the moment, you lose any benefit of separating them.
 
DemiLion said:
Tony the major difference with how it's set up at the moment, is that the shutter button will over ride the AF-On. By choosing C.FnIV-1-2 you're removing any AF function from the shutter. By leaving it as it is at the moment, you lose any benefit of separating them.
Click to expand...
What he said

It needs to be changed in custom functions
 
I appreciate this is a bit after the original post, so may get lost in space somewhere but.....

Firstly I'm not sure why I'm interested in this, but I'm always open to new ideas :)

I understand BBF is used for recomposing after gaining initial focus, but I currently use the multi selector for this and move focus point manually. Someone has said that the centre focus point is the most accurate, suggesting the others aren't? Or do you just mean the other focus points don't lock focus as quickly?

However for action sports, (in my case, Polo) I'm not convinced of the advantage yet. I fail to see how when shooting horses running towards you at speed, using the back focus button, when shooting in manual exposure mode, is going to be any advantage :shrug:

Anyways, I'm definitely going to have a play with the dogs tomorrow outside.

Just to confirm, if I'm shooting the dog running towards me, I need to keep my finger on the AF button, so it's continuously focusing?
I can currently achieve 100% in focus without using BBF, I don't even know why I'm trying it :bonk:


Oh, and KIPAX, how did you get on with it?
 
Yes - you need to set the camera to AF-C on the front 'C' and then when you hold the button it will continuously focus. Also give 51pt 3D a rey - it will lock and and the focus point move with the subject. Pure Nikon Magic!
 
well its 8 days since I asked the question .. I said I would try it out as soon as I find a non important game.. in those 8 days I have photographed 7 full football matched and all commisioned.. so I just havent had chance.. and am booked most of this wek... looks like I wont get a chance to try it for yonks.. but the upside is.. business is good :)
 
I used it on my old 1dmkII, Its in the custom functions menu.
Its hard to get used to..But good to use
 
Looks like M&M were slower than usual at spotting him!!!!!!!!!!!!!!1 :lol:
 
I went out today with the intention of trying the AF-On when taking pics of some local football. I put the grip on my D300S, for the extra power and more comfortable vertical shooting. However it wasn't comfortable using the AF-On button either on the grip or on the body. A bit too far for my little chubby fingers. :( :lol:
 
At last I finally managed to try BBF properly. I have used it for the last week or so at 6 football matches and I am sold..

I had some focus issues and was convinced it was canon. I could take 3 shot bursts and one would be out of focus sometimes 2, Now I dont get any out of focus and has cured all the problems I had which was obviously user error :( So as Gary Coyle stated.. OOF problems massive difference.. Still get OOF but I can tell at the time its me :)

My hands arn't small and I took Mark (whiteflyers) tip and swapped the AF-ON / * buttons and thats a lot more comfortable.

Its taken a lot of getting used to.. I lost some prsentation shots at a cup final because it still lets you half press and all looks well in the viewfinder and no alert on AI to say if in focus.. Sometimes even tried to fire with back button... 90% used to it now and theres certainly no going back.. deffo improvement :)
 
KIPAX said:
At last I finally managed to try BBF properly. I have used it for the last week or so at 6 football matches and I am sold..

I had some focus issues and was convinced it was canon. I could take 3 shot bursts and one would be out of focus sometimes 2, Now I dont get any out of focus and has cured all the problems I had which was obviously user error :( So as Gary Coyle stated.. OOF problems massive difference.. Still get OOF but I can tell at the time its me :)

My hands arn't small and I took Mark (whiteflyers) tip and swapped the AF-ON / * buttons and thats a lot more comfortable.

Its taken a lot of getting used to.. I lost some prsentation shots at a cup final because it still lets you half press and all looks well in the viewfinder and no alert on AI to say if in focus.. Sometimes even tried to fire with back button... 90% used to it now and theres certainly no going back.. deffo improvement :)
Click to expand...

for us canon users could you please let us know which cf it is and the setting you are now using
 
admirable said:
1DIV settings,

Custom function 4: operation others

1/ Shutter button/AF-On button, set this to No2 - Metering start/Meter + AF start
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thats the setting as posted earlier in this thread.. to swap buttons is the very next setting ie 2/ lock button switch

i havent changed any other settings bar those two :)
 
Its one of those "should have done it years ago" moments.. simmilar to my first prime lens :)
 
Glad you getting use to it Tony.
You'll find it hard to go back now :)

For those who require a little bit of info, Canon do some very nice videos, which can be downloaded to your camera for viewing anytime if you wish.

The Back Focus on the 1D IV is video number 12 from HERE
 
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KIPAX said:
At last I finally managed to try BBF properly. I have used it for the last week or so at 6 football matches and I am sold..

I had some focus issues and was convinced it was canon. I could take 3 shot bursts and one would be out of focus sometimes 2, Now I dont get any out of focus and has cured all the problems I had which was obviously user error :( So as Gary Coyle stated.. OOF problems massive difference.. Still get OOF but I can tell at the time its me :)

My hands arn't small and I took Mark (whiteflyers) tip and swapped the AF-ON / * buttons and thats a lot more comfortable.

Its taken a lot of getting used to.. I lost some prsentation shots at a cup final because it still lets you half press and all looks well in the viewfinder and no alert on AI to say if in focus.. Sometimes even tried to fire with back button... 90% used to it now and theres certainly no going back.. deffo improvement :)
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I thank you, er ang on a minute shouldn't that be the other way round. :D

Next up is Marital advice and the perils of a fried breakfast

Seriously though mate, glad it's worked out for you, oh and i just wanna say..........................................................................
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I told you so. :lol:
 
I'm just wondering how Gary has so much experience with OOF shots.....cue anti Canon joke.... :lol:


Glad that you've settled into using it Tony, I hope work isn't giving you a heart attack from the overload at the moment!! :D
 
I dunno, maybe I'm an alien or something, but I tried it (shooting in manual, on moving subjects), and it made no difference what so ever, other than complicating things by having an extra button to press :shrug:

My shutter release button seems to do the same thing.

With the exception of Gary, it seems to be particularly popular with Canon shooters....maybe I should leave it there......:)
 
treeman said:
I dunno, maybe I'm an alien or something, but I tried it (shooting in manual, on moving subjects), and it made no difference what so ever, other than complicating things by having an extra button to press :shrug:

My shutter release button seems to do the same thing.

With the exception of Gary, it seems to be particularly popular with Canon shooters....maybe I should leave it there......:)
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And with the exception of 99% of pro sports shooters as well :thumbs:

It also works in connection with various other combinations of custom functions.
 
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Firstly, I can assure you, I'm not trying to pick an argument, but I genuinely don't understand how it can be an advantage. I don't dispute for a second, most pro sports folk use this method, and as I'm desperate to learn as much about sport shooting as possible, is the reason why I'd like to get to the bottom of this. :)

I fully understand if you want to focus and recompose on a still subject, or you want to use auto metering. But on manual exposure, with a subject moving towards or away from you at speed, surely that button is doing nothing different to the shutter button.

Or are you saying the BFB keeps focusing right up to shutter realise, whereas the shutter release button doesn't so much?
 
Youve tried it, you dont like it, its alien to you and it made no difference what so ever, hey im not going to preach to you other than say according to your profile you shoot Nikon but this info is specific for Canon eqipment so thats why it probably doesnt work. :lol:

However similar functions exist for Nikons
 
I've done a little hunting around interweb, and it does seem to be born out of Canon cameras. Something to do with on one of the bodies it was difficult to select a different focus point?
Having always used Nikon, and been able to select a different focus point very quickly, and knowing (possibly unlike a Canon) that it will be as good at focusing as the centre point, is why I don't see its advantages.


Hey Ho, I like to be different :)
 
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