What are the typical situations where you should use AE for locking exposure?

  • 1
    I'm not sure I understand the question, could you explain a bit more?
    – Matt Grum
    Jun 28, 2011 at 21:35
  • 2
    @Matt I suspect he means AE Lock
    – Imre
    Jun 28, 2011 at 21:41
  • Yes, that's what I mean.
    – Kreker
    Jun 29, 2011 at 6:47

6 Answers 6


AE Lock is for situations where you want to use metered exposure later than you metered it:

  • locking exposure capturing parts of a panorama - for seamless stitching, frames with similar exposure will work better than differently exposed ones;
  • when you meter from a gray card, lock exposure, then remove the gray card and compose;
  • you point your camera on a surface that should be exposed as 18% gray, lock exposure, recompose
  • as @mattdm commented - when there are areas that would confuse matrix metering, compose so they are excluded, lock exposure, recompose

AE Lock can be thought of as a "quick version of temporary M mode". As such, you can quickly lock metered exposure and take a few shots with it. Most cameras will unlock AE after some idle time, so manual mode is more suitable when you work slowly and want to tweak things little by little.

  • 1
    +1. Another case; when you're using an average or matrix metering mode, but know that something particularly bright (or dark) will confuse the system. Frame with that excluded, lock, and recompose.
    – mattdm
    Jun 29, 2011 at 2:05
  • Do people really use this for panos? I always thought that Manual is the way to go. With this method you will have to be very precise in metering the exact same point for all the frames - which seems to be a little hard to do, especially for wide panos.
    – ysap
    Jun 29, 2011 at 10:10
  • @ysap you're right, it seems more suitable for a quick pano consisting of 2-3 shots, such as when your tour bus is about to departure. I'm kinda slow myself (or so I've been told at home), so I usually prefer manual mode too. Edited to include that difference between AE-L and M.
    – Imre
    Jun 29, 2011 at 11:32
  • 1
    I used to do the same exposure for each frame in a pano, back when I was assembling them by hand. Now I use evaluative metering and lots of overlap. The stitching software smooths out the brightness changes and you get a nice even brightness across the panorama. IF you shoot manual or lock AE you tend to get one bright half and one dark half...
    – Matt Grum
    Jun 29, 2011 at 15:18

Many people use "focus and recompose" to both focus and meter a specific location, then recompose the image without changing the settings. AE lock is a specific part of that puzzle, the metering. If there is a particular part of the composition you feel you need to meter for, then you can do that and set AE lock.

I don't personally use AE lock because I normally shoot on M anyhow. When I'm moving fast, I find my Canon cameras do fine if I focus/meter and keep the AF button down until I've recomposed. But it's all about personal preference. If you like locking in an exposure, or as previously mentioned, are shooting an 18% gray card, then AE lock makes sense.


I often use it when spot metering. I can press the "fn" button on the front of the camera to turn spot metering on, take a reading from the specific point I want, press the AE-L button, then recompose and refocus using the AF-On button before finally pressing the shutter to make the shot.

When you have the metering, focusing and taking the shot all as separate functions and not combined all into one with the shutter button you'll find you can work faster, smarter and better!


I tend to use it in situations in dark situations with lots of shadows (like a dark room with a just a spot of light from a small window or lamp). I measure the exposure where I want and then recompose the way I want.

  • This also works in very bright and backlit situations and works well to create "high-key" pictures.
    – user2802
    Jun 29, 2011 at 10:53
  • fwgx: Indeed! Exactly the opposite of my scenario. The truth is I shoot low key photos more often.
    – t3mujin
    Jun 29, 2011 at 13:11

I have used AE-L when taking sunset pictures. I would aim the camera so that the sun is just out of the shot, use AE-L to lock the exposure then recompose with the sun in the frame where I wanted it keeping the exposure locked in at the previous spot.

I do not normally shoot in manual so this allows me to get a correct exposure without too much effort on my part since I am still learning how to shoot in non-auto modes.


If you are using a Nikon DSLR here is a quick tutorial from the Nikon site:


  • 4
    Hi @Scrappydog - Can you summarize some of the article, rather than just dropping the link? That way our users don't have to navigate off site to get the 'gist' and we guard against the link eventually dying and this becoming useless internet clutter. Thanks!
    – rfusca
    Jun 28, 2011 at 22:03
  • @rfusca Opinion noted... But in this case the link includes some great illustrations to explain the answer that go beyond what we can do here on a StackExchange site. If somebody else wants to write a better answer great, but at the time I responded there were no other answers and this is a great article.
    – Scrappydog
    Jun 29, 2011 at 19:15
  • @Scrappydog - Great article or not, you're perpetuating a bad habit. Doing illustrations and diagrams is most definitely not beyond SE - see photo.stackexchange.com/questions/6598/… and photo.stackexchange.com/questions/11878/… and photo.stackexchange.com/questions/12200/… ...
    – rfusca
    Jun 29, 2011 at 19:47
  • 2
    @rfusca FYI you blew up this user. I think you could have been a bit more tactful in the way you expressed the information. (and I edited your comment to remove "piss poor") Jun 30, 2011 at 0:13
  • 1
    @JeffAtwood - I am sorry that the user left and I do regret my choice of diction there for sure (it was beyond my edit time for removing the words myself once I had decided against it). I'll try to be more tactful in the future then.
    – rfusca
    Jun 30, 2011 at 0:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.