Have you got your exposure locked to the focus?

[ricstew]

I cant decide............
and what is the purpose of being able to change the metering time?
I think I am going back to spot metering ( I only seem to shoot manual with any lens ) tho I have been using the centre weighted.......

then the book tells me that S/S and AV change depending on the zoom position....even while the AE lock is engaged when using a zoom lens for which the max aperture varies according to the focal length. However the exposure value does not change and the pic is taken at the brightness level set by the AE lock............:confused013
What if I am being artyfarty and dont want the aperture to change? Dont lock it?
yikes
cheers
Jan

[Kym]

Lock yes, but I can override with AE button when needed

[Xenedis]

No; I disabled AF on the shutter release, and instead control it separately using the dedicated AF-ON button on the back of the camera.

[arthurking83]

No; I disabled AF on the shutter release, and instead control it separately using the dedicated AF-ON button on the back of the camera.

:th3:

can be a very important camera setup for landscapes

[Xenedis]

can be a very important camera setup for landscapes

Indeed; most of what I shoot is 'scapes.

it's also handy when using the focus-and-recompose technique in any situation, as you don't necessarily want to meter again.

[ricstew]

You lost me on this bit.......... disabled AF on the shutter release.........you disabled the Auto Focus?
No wait I get it........the little button on the back with AF.......you use that to AF.......and the shutter release to metre?

[Xenedis]

You lost me on this bit.......... disabled AF on the shutter release.........you disabled the Auto Focus?

I disabled AF on the shutter release button only. My camera (Canon EOS 5D Mark II) has a dedicated AF-ON button on the rear panel.

Using a custom function in the camera's menu it's possible to disable the AF capability on the shutter release button so that you have independent control; ie, metering, AF and exposure are not all triggered by one control.

[ricstew]

Thank you! I just found it! and the button to metre! blooming heck its a bit like math...........how many ways to express a fraction is there in photography.....
going off to find my model........

[arthurking83]

You lost me on this bit.......... disabled AF on the shutter release.........you disabled the Auto Focus?
No wait I get it........the little button on the back with AF.......you use that to AF.......and the shutter release to metre?

Yep! as Xenedis explained. depending on what camera you;re shooting with. If you can't find it in the camera setup menu someone with the same camera brand or model can help to explain.

On the Nikon's(that have it) ... the setup will look like

AF activation:
(two options are)

(1)Shutter/AF-ON
(2)AF-ON only

Set it to (2) only and the focusing via the shutter release is disabled and only the AF-ON will give AF.
Set it to (1) and both shutter and AF-ON buttons will give autofocus.

once you're used to AF-On only, I doubt you'll ever go back either.

Note too tho(if your camera has this option too) set the Priority Selection to the release, not focus
What this means is that the camera will always expose, irrespective of whether focus is achieved or not.

if you focus and recompose and therefore lose focus, having Priority Selection on focus and not release can mean that you have to continually refocus just to get the camera to make the exposeure.

doing all of this minimises the need to flick between manual and auto focusing modes.

[Dylfish]

i might have to toy with mine then, im doing alot of landscapes atm so we'll see how this helps

[TOM]

so when you disable the AF from the shutter button, and you should, then you'll want to set the camera to Continuos Focus. That way the camera will focus constantly whilst the AF-On button is depressed, and you simply release when you want to stop focusing. For portraits, you can just tap the AF-On button, then shoot away without having to focus again until you or your subjects move.

[ricstew]

ok I have worked out how to do it and the camera is set that way............but what are the advantages of this? It feels really weird..........

[maccaroneski]

Give it 2 weeks and you won't go back.

I utilise this method as well: use the back button with the right thumb to engage autofocus, and the shutter button if I want to lock exposure.

There was mention above of the "focus and recompose" method. Basically I have the autofocus set to use just the centre focus point (in my camera it is a "cross" type focus point and thus more accurate. I "bullseye" the subject that I want to focus on (i.e. get the centre focus point over that area of the scene) then let the button go, and frame the scene as I wish. When I then hit the shutter button to shoot, the autofocus does not re-engage

If you are shooting action, you can then simply hold the thumb focus button down and follow the action, shooting when you wish (I have the focus set to AF-C, or continuous focus, that is, that as long as the button is down the camera will continue to engage the autofocus).

If you want to lock exposure, either by using spot metering or any other method, you can pick the thing you want to meter, and then half-press the shutter button to lock it (again without that actoin engaging your autofocus).

I too found it weird at first, but now I get thrown if someone hands me a camera and autoficus is engaged by the shutter button. I feel that the "new" method gives me a great deal more control as the concepts (as well as the buttons) for autofocus and exposure lock are separated in my mind.

[ricstew]

well I will give it a burl.......I havent tried AF-C......most things I shoot are very still......but I have a couple of babies coming up........( my best mates grandkiddies ).......
Many thanks
Jan

[maccaroneski]

Jan even if you're not shooting action AF-C is the way to go with this method.

[arthurking83]

ok I have worked out how to do it and the camera is set that way............but what are the advantages of this? It feels really weird..........

I think there are many ways to explain the advantages in real user terms, just as there are many ways to write the same fractions.
But the overall advantage is that you have full control of the focus system.

think of it as a 'manually settable auto focusing mode'. With having the shutter release as the focusing method, every time you half or full press the release the camera always focuses(it has to that's what it thinks you're telling it to do).
While for many shooting situations this isn't a problem(or could be an advantage) in reality it can be a hindrance for all situations.
eg. two situations where I see the biggest advantages(for me). some lenses like to hunt during their focusing routine. My worst lens for this is the Nikon 105VR. Annoys the hell out of me as it focuses well(accurately) but sometimes needs the focus limiter to be switched on. it has a long focus throw and focuses very closely(macro) and so sometimes it winds all the way in and then all the way out. Common sense would usually be to flick the focus limiter switch, but in quick paced situations you may need to take your eyes off the action(the switch is not very well differentiated from the VR switch) ... this is not ideal. But with the AF-On method, i tap the focus button on for a brief moment and then release it.. it gets closer to where the focus should be and then I tap the AF-On button again.. generally this gets me much quicker focus lock than waiting for the lens to spool in and out and then in again, or to manually flick the (long travel) focus ring. So my usual routine(when this lens causes me trouble) is to tap.tap.hold the AF-On button. Easy as pie :th3:

other situations for my main use is in landscapes. I'm very selective as to where I want to meter the scene.. D300 is the best camera as I can spot meter from nearly the entire frame as seen through the viewfinder, as the focus point coverage is very broad. But I want to focus on something else. I calculate the metering I want on just about any point in the frame, but manually choose the focus point earlier and forget it and leave it there(say centre of the frame).
If I'm metering at near one of the corners, and I have the camera set to focus with every shutter press(as opposed to the AF-On method) every exposure I have to either switch the focusing system to manual or the camera focuses at a point i don't want it too.
As you said there are many ways to do the same thing.. flick this switch adjust that lever.. etc, etc... this just makes it easy with a press of a single button(using your thumb) which would almost certainly fall naturally in the correct spot anyhow.

funny how there have been many recent discussions about upgrading camera bodies and whether these upgrades are worth the effort.
my main reasons for upgrading from the Nikon D70s to the D300 was based on having mirror lockup and metering with old manual lenses.. (I've never had AF SLR's until the digital age) I never knew of or thought that i would rely on this feature so much(primarily as a landscaper). I think overall this is the biggest benefit in that upgrade path(for me).

Note many cameras that i know of can be set to use the exposure lock button to act a AF-On button.. but doing this comes at the expense of losing the exposure lock function. The benefit is still there, but not ideal.

[rocklogic]

decided to try this function - and I'm bloody loving it!

Thanks folks!

[Lani]

It does feel weird initially, but once you do get used to it, its the most efficient method to select focus. The only catch is if you give your camera to someone who doesn't know about using the AF button, they think your camera is broken because the damn thing won't focus! :D

[maccaroneski]

It does feel weird initially, but once you do get used to it, its the most efficient method to select focus. The only catch is if you give your camera to someone who doesn't know about using the AF button, they think your camera is broken because the damn thing won't focus! :D

Indeed. I have since put the entry to change it back into "My Menu" so I can change pretty quickly.

[fillum]

It looks like I'm the odd one out. I prefer focus lock on shutter half-press and use the exposure-lock (AE-L) button when needed (which is not often for me). My aging brain finds it difficult enough controlling one finger without adding my thumb to the mix :D.

I have the AE-L button set to 'toggle' (reset on release) mode so that I don't need to need to keep the button pressed after metering.


Edit: Nikon D300 btw


Cheers.

[fillum]

Just re-read your original question and don't think it's been answered...

then the book tells me that S/S and AV change depending on the zoom position....even while the AE lock is engaged when using a zoom lens for which the max aperture varies according to the focal length. However the exposure value does not change and the pic is taken at the brightness level set by the AE lock............:confused013
What if I am being artyfarty and dont want the aperture to change? Dont lock it?
Probably easiest with an example. My Nikkor 18-200 has a variable max aperture between f/3.5 and f/5.6. Say I meter at focal length of 24mm and f/4 and get 1/800 s/s and lock that exposure. I then zoom to 135mm which has a max aperture of f/5.6 on this lens. The camera can no longer use f/4 (as f/5.6 is now the limit) so it adjusts the s/s to 1/400. This is the same exposure value as originally locked in (1/800 @ f/4 = 1/400 @ f/5.6). If I started at 24mm and f/8 (s/s would be 1/200 for same conditions) and then zoomed to 135mm the aperture and s/s would not change as f/8 is within the limit of max aperture at that focal length. Hope this makes sense. (Note that in reality if you zoomed from 24mm to 135mm you would likely meter again - I just used these examples to make the 'math' easier. The same principle applies zooming from 18mm @ f/3.5 to 20mm @ f/3.8).

(This is how my D300 works, I would assume that most cameras operate in a similar fashion)


Cheers.

[umajo]

this is what i love about this site always learning
i have just tried this and love it, as a bird photograher i think it could be very useful. thankyou:):D

[umajo]

repeat useless internet drops out and then sends post twice

[reaction]

So why do people not have AE-L set on shutter half-press?
This is where you're focus-and-recomposing from, but default does AE on full press

Plus many flash modes do metering based on FP, so with focus-and-recomposing it'd end up AE on the wrong thing?
:eek: