By now you will hopefully have figured out how to use many of the features of your Samsung NX300. One of the features, though not so obviously placed, is the Auto Exposure Lock or AEL.
When taking photos you will run into situations where you want to recompose the scene but not change the exposure. Recomposing/re-positioning is when you decide to change where your subject/object will be placed e.g. instead of directly in the middle you choose to place the subject/object slightly to the side. Doing so can change the exposure when you don't want it to and that's one of the times where AEL comes into effect.
But, recomposing requires that you keep the focal plane the same i.e. the distance between your camera and the subject/object the same.
Before going into AEL let's quickly discuss Recomposing. When you press the shutter half way down you are locking in the focus (plus the exposure) and if you decided to recompose (change the where subject/object is placed) you would need to make certain the subject/object remains at the same distance because any change in distance will affect the focus. In other words, you could go from having the subject/object in focus to being out of focus if distance changes.
For a more detailed explanation take a look at this article: Recomposing
What's the point of AEL if you can just half press the shutter to lock in exposure and focus?
AEL helps in situations where the camera under or overexposes part of the scene e.g. the camera might expose for the background (so it will be properly exposed) but the foreground may be too dark. It makes metering easier, especially for those who don't have a full understanding of how Aperture, Shutter and ISO work together.
A quick note: AEL doesn't work in Manual because Manual is controlled by you. It works in the following shooting modes: PAS.
To activate: Go to Menu, select the icon below the video camera that looks like a little person (3rd menu icon from the top). Scroll down to Key Mapping, press OK and under Custom select either AEL or AEL Hold. The Delete button (the trashcan bottom right of camera) is used as the Custom button and for AEL when the function is assigned to it.
AEL, when pressed to lock exposure, will lock it until you have taken the photo.
AEL hold is pretty obvious, it will hold that exposure even after you have taken the photo and this can be very useful for Panoramas and photo stacking where you want the exposure to be consistent.
AEL doesn't depend on recomposing to work, but recomposing works better with AEL. So you can change the focus plane (distance between camera and subject/object) and keep the exposure the same when using AEL and not worry about focus.
How to use AEL:
1. Make sure that AEL or AEL Hold is selected in your Menu options.
2. Select a shooting mode, either Program (P), Aperture Priority (A) or Shutter Priority (S) but not Manual. Remember this doesn't work in Manual.
3. Decide on your shot and place the focus point over the area you want to expose (use the exposure) from, even zooming in if needed. Press the Delete/Custom button, which then locks the exposure.
Since the Samsung NX300 holds the exposure until you take a photo, you can safely release the Delete/Custom button, recompose and take a shot. You won't have to worry about the AEL deactivating until the shot is taken. But, if you take too long and your camera goes into sleep mode, AEL deactivates.
4. Recompose your photo, half press the shutter to gain focus and take the shot. The exposure will remain the same because you locked it in so the camera won't take another reading of light.
Keep an eye on your settings and practice with taking different exposures as you may not always get the result you expect. This is where you learn about how shutter, aperture and ISO work.
I try to find articles that are easy to understand as well as helpful. Below are two links that will give you examples and more insight into using AEL.
Digital Camera World
Auto Exposure Lock
I'll play around with the other features under Custom (which was originally as preview for Depth of Field) and post as I go along.
Wishing everyone a great New Year!