When to use the AE-L button?

[atyab]

I have had my K200D for around three months now and almost every once in a while I discover something new about it. I never actually used the AE-L button but now I am getting curious about it. Its located right close to the thumb so must be something really important and useful.

So, when does one use the AE-L button and why?

I watched a video on youtube in which a guy says that he uses it to take panorama pictures. I don't do that at all. So, what else can it be used for?

[flyer]

When you have a lot of pictures to do with the same exposure compensation, you use the exposure compensation, but for a one shot deal, it is easier and faster to use exposure lock. You just point the camera in a direction that will give you the exposure you want, push the button, reframe and shoot. When your subject is backlit, generally pointing it down will bring a reading that is OK, so you push the little button, and, in no time, you're set to take your picture.

[dadipentak]

Good question & helpful answer.

[bnishanth]

AE-L is used to lock exposure and once pressed you will see a '*' confirming that the exposure has been locked on the bottom display in viewfinder. This setting will remain for 30 secs (guess this value can be changed) which allows you to reframe the shot and click.

This can be extremely useful when using Spot metering. Just point at a spot which you think has ideal exposure and press the AE-L. Now reset your frame and click. When you click, the camera will not meter again (unless you take more than 30 secs to click).

Cheers
Nish

[pcarfan]

Also, in the Manual mode, pressing the AE-L button will keep the exposure the same as you adjust the aperture or shutter.

[kristoffon]

or if your composition has a very bright spot where you want to expose for the rest of the scene (such as a sunset or lamp) you move the camera sideways to exclude that bright light, lock the exposure, compose the picture and take the shot

[senojobmij]

Originally Posted by pcarfan

Also, in the Manual mode, pressing the AE-L button will keep the exposure the same as you adjust the aperture or shutter.

I find this to be one of the more useful features of the AE-L button. I've had my K10-D for almost a year and I just discovered this feature about 2 weeks ago.

[NorthPentax]

I use the Auto Exposure Lock button all the time. You want to expose for the highlight, not always. But most of the time you don't want to burn out those highlights. I rather pull out details from the shadow area than having the highlight blown out with no detail. It's possible to pull out up to one stop from the highlights when you shot RAW, if you shot jpg the highlights are gone forever if you overexpose.

[grainbelt]

Originally Posted by pcarfan

Also, in the Manual mode, pressing the AE-L button will keep the exposure the same as you adjust the aperture or shutter.

*furiously takes notes*



Another n00b questions - do you have to turn off 'AE-Lock when focus is locked' in custom settings for all this to work?

[Saaby]

and another question, and I think it ties into the question in the post immediately preceding this one:

Can you not accomplish the same thing by pressing half way with the lens pointed at your exposure point, and then reframing?

I think I may have just answered my own question -- this is how most P&S work, but that locks the focus _and_ exposure. With AE-L you can lock your exposure and focus separately, because the are you want to auto-focus on may not be the area you want to meter on.

[Marc Sabatella]

Originally Posted by Saaby

and another question, and I think it ties into the question in the post immediately preceding this one:

Can you not accomplish the same thing by pressing half way with the lens pointed at your exposure point, and then reframing?

If you've set the custom option to lock exposure with AF, yes.