Exposure Lock funtion

[GeckoZ]

Hi, I'm wondering when should the exposure lock function be used.

What I'm thinking is that, it's for the camera to know how to expose the photo for you, so you should only use it when doing auto or semi-auto mode instead of manual mode.

Is my concept correct??

[ExplorerZ]

Originally Posted by GeckoZ Hi, I'm wondering when should the exposure lock function be used. What I'm thinking is that, it's for the camera to know how to expose the photo for you, so you should only use it when doing auto or semi-auto mode instead of manual mode. Is my concept correct??

In manual mode, you can't exposure lock as you are the one who are having full control on the setting... it can only be use on aperture/shutter/program mode and i believe as well as scene mode.

[bernardy4416]

Originally Posted by GeckoZ Hi, I'm wondering when should the exposure lock function be used. What I'm thinking is that, it's for the camera to know how to expose the photo for you, so you should only use it when doing auto or semi-auto mode instead of manual mode. Is my concept correct??

Hi GeckoZ,

exposure lock is useful if you intend to use a small part of the picture for metering.

For example, start up your camera, half depress the shutter release button, then move the lens around. You should see both the aperture and shutter speed change as you move the camera around.

Suppose you intend to use a specific point to meter, say in a silhouette shot, for instance. You would use spot metering off the brighter areas of the picture, push the exposure lock, recompose, then take the shot.

As ExplorerZ as stated, it's useful except in manual mode. In manual mode, you would have to make the decision using the metering on the LCD screen.


Bernard

[zac08]

This works only if you're using centre-weight or spot metering...

[miniUltraman]

Originally Posted by zac08 This works only if you're using centre-weight or spot metering...

How do you determine the exposure in Manual mode if you are shooting like the merlion? You don't want the merlion to appear in the centre of your composition.

[GeckoZ]

Thanks Zac, Bernard and ExplorerZ! Explaination simple and clear.

Originally Posted by miniUltraman How do you determine the exposure in Manual mode if you are shooting like the merlion? You don't want the merlion to appear in the centre of your composition.

you can 1st use spot metering to meter the merlion, set the aperture and shuttle setting manually, and then recompose your photo.

[miniUltraman]

Originally Posted by GeckoZ Thanks Zac, Bernard and ExplorerZ! Explaination simple and clear. you can 1st use spot metering to meter the merlion, set the aperture and shuttle setting manually, and then recompose your photo.

You mean in "M" mode, point at the merlion, remember the settings (cos Manual can't use exposure lock), recompose and set back the setting you remembered?

[zac08]

Originally Posted by miniUltraman You mean in "M" mode, point at the merlion, remember the settings (cos Manual can't use exposure lock), recompose and set back the setting you remembered?

M mode... spot metering

Choose a neutral spot on the merlion and then set the correct exposure of aperture and shutter speed, then recompose and shoot.

[miniUltraman]

Originally Posted by zac08 M mode... spot metering Choose a neutral spot on the merlion and then set the correct exposure of aperture and shutter speed, then recompose and shoot.

Got you!! Thanks

[catchlights]

Please note that all meter reading are calibrate to produce mid tone.

merlion is white color, if you spot metering on the merlion, it will come out a "gray" merlion.

however you can:

#1, find a mid tone area on the merlion and take meter reading from there.

#2, meter the white area of merlion, then open up your exposure two stops and make the shot (two stops over of "mid tone" is "important highlight" or "white with detials")

[GeckoZ]

Originally Posted by catchlights Please note that all meter reading are calibrate to produce mid tone. merlion is white color, if you spot metering on the merlion, it will come out a "gray" merlion. however you can: #1, find a mid tone area on the merlion and take meter reading from there. #2, meter the white area of merlion, then open up your exposure two stops and make the shot (two stops over of "mid tone" is "important highlight" or "white with detials")

oh ya, the most important point being missed out. Thanks!

[bernardy4416]

Originally Posted by catchlights Please note that all meter reading are calibrate to produce mid tone. merlion is white color, if you spot metering on the merlion, it will come out a "gray" merlion. however you can: #1, find a mid tone area on the merlion and take meter reading from there. #2, meter the white area of merlion, then open up your exposure two stops and make the shot (two stops over of "mid tone" is "important highlight" or "white with detials")

Same goes with most white coloured subjects (eg: swans, snow, etc...)

Always better to over expose 1 - 2 stops for that "extra white" look



Bernard

[sammy888]

Originally Posted by zac08 This works only if you're using centre-weight or spot metering...

Actually it works on Matrix Mode on the Nikon too.

[ah.zeep]

Originally Posted by catchlights Please note that all meter reading are calibrate to produce mid tone. merlion is white color, if you spot metering on the merlion, it will come out a "gray" merlion. however you can: #1, find a mid tone area on the merlion and take meter reading from there. #2, meter the white area of merlion, then open up your exposure two stops and make the shot (two stops over of "mid tone" is "important highlight" or "white with detials")

Originally Posted by bernardy4416 Same goes with most white coloured subjects (eg: swans, snow, etc...) Always better to over expose 1 - 2 stops for that "extra white" look

I read somewhere on how someone uses spot metering: either
a) Point at the brightest portion of the scene that you don't want to blowout, and meter,
or
b) Point at the dimmest portion of the scene that you don't want to lose detail, and meter.

I suppose one can apply (a) or (b), and then + or - achieve desired exposure levels...

[ah.zeep]

Originally Posted by sammy888 Actually it works on Matrix Mode on the Nikon too.

It works but will probably not be as precise in Matrix Mode vs Centerweighted/Spot metering...

[catchlights]

Originally Posted by ah.zeep I read somewhere on how someone uses spot metering: either a) Point at the brightest portion of the scene that you don't want to blowout, and meter, or b) Point at the dimmest portion of the scene that you don't want to lose detail, and meter. I suppose one can apply (a) or (b), and then + or - achieve desired exposure levels...

your a + b method is call average metering, it will work, if the range not beyond the exposure latitude of the medium (film or digital)

[catchlights]

Originally Posted by ah.zeep It works but will probably not be as precise in Matrix Mode vs Centerweighted/Spot metering...

it depend how well the photographers understand the differents of metering mode, eg, the photographer can just zoom in, take a reading with matrix mode, lock the exposure, zoom out, re-compose the framing, shoot.
instead of reselect the metering mode, take the meter reading, lock the exposure, re-compose the framing, shoot.

[sammy888]

Originally Posted by ah.zeep It works but will probably not be as precise in Matrix Mode vs Centerweighted/Spot metering...

Yes you are right but that is more a general average as compared to center-weighted and spot which is more precise. I find matrix more average in its exposure mode so just by aim to a darker or highted area and then lock down the EL...I can go back to the same position and shoot the scene with just a subtle change in the exposure. With spot ,metering which I tend to favour over center weighted ( unless I set my DSLR setting to make the center weight area really small) I get more control over the exposure. In fact I like to take readings from all light intensity of the scene I am shooting and then with that information will imagine how it would look, how much details I am willing to loose in some parts of the shot or some parts to really darken to get that shiloutte look. We can't always leave everything to the camera to decide for us how we want to "make" that shot. You have to know your camera and how all the metering works and then with trial and error you can read more into the settings and know when to use exposure lock to pick a lighting intensity of your choice and use that as your overall effect to the final look of your shot.