AE Lock in Manual Mode

Discussion in 'Canon EOS' started by milton-chris, Feb 24, 2007.

  1. This is probably another case of me being thick as a brick . . .

    Why is there no AE Lock in M mode (XTi)? I think I might know the answer, not
    sure how to word it, so, please, "splain, Ricky, splain".

  2. Manual mode = no auto exposure
  3. In manual mode you have already locked the exposure through aperture and shutter speed settings. As you point the camera at different parts of the scene nothing changes since you have set the exposure.

    As an example, suppose you want to shoot a person silouetted against a bright background but with the person appearing at the side of the image. So you aim the camera at the person, adjust aperture and shutter speed, then recompose and shoot. There is no need for an AE lock.

    But in automatic exposure mode, the camera's aperture and/or shutter speed settings will change as you aim the camera in different directions. AE lock is intended to prevent that.

    In the above example, if you have the camera in auto mode, you aim at the person, hold the release button half way, then recompose. But the camera's exposure settings will change as you recompose. To prevent that, you hold in the AE lock button while recomposing.

    I always use manual exposure since I find it easier than holding in an AE button while recomposing a shot.

    When shooting outdoors, I find I have to manually set exposure only once. Unless the lighting conditions change dramatically, I don't have to readjust more than one stop or so. Also, most outdoor shots are focussed at infinity, so I just leave my manual focus lens set there. The camera then becomes a very reliable point and shoot.
  4. Thanks Guys. I understand both of the responses, and understood things correctly. Where I was starting to question my own sanity/brick-thickness was because Bryan Peterson, in 'Understanding Exposure' talks about shooting in manual mode and then makes reference to using exposure lock once you have set focus someplace such as the sky, then re-composing your scene. It didn't make sense, but it doesn't matter because since starting to shoot manual and focusing off-composition such as sky for snow shot, my pics are far nicer to look at.
  5. While this may not be totally useful, it would be nice if the AE lock were to lock the 'metering value' when in 'M' mode. I guess it would just give the button some sort of function when it has no other use.
  6. Some areas in Peterson's book refers to setting an exposure pointing in one spot, then
    framing elsewhere, but to ignore the camera's warnings. Given that the camera doesn't know
    what the photographer has in mind when doing this.
  7. I tried to post this but it disappeared. Will try again. I'm confused & frustrated by the same issue. I have my camera (Canon Rebel) aperture set, aim at the sky & set my shutter speed according to my exposure compensation reading. But when I go to recompose the shot the exposure needle is jumping all over. Is it changing my settings or do I just ignore this. Please help.
  8. Manual mode locks the aperture and shutter speed, so the metering will jump around depending on what the lens is pointed at. So long as you meter appropriately when setting the exposure, you can safely ignore the meter afterwards (at least while the lighting is still the same).
  9. Ah so I don't have to be chasing that needle around & resetting! As long as the lighting remains the same as you
    say, having set the shutter speed & aperture I guess this would also mean that I can if I so choose take another
    shot using the same settings as long as the lighting doesn't change. Just check my histogram for insurance. If
    I'm correct here, then I must express my deepest thanks for finally put my frustration to rest.
  10. I just bought Canon 1d mark III. I try to use AE Lock, but it's doesn't work. I follow the instruction, I aim a dark area of a subject, press shutter halfway, then press AE Lock bottome, but I don't see * appears in viewfinder. Can anyone help me how to set up AE Lock? Thank you so much.
  11. sounds like you might be in manual mode in which case ae lock is not necessary since you're not in automatic exposure mode.
  12. Exposure Lock in Manual Mode is or would be VERY useful particularly in cameras with only one Command Dial (i.e. Canon T3i, Nikon D3100/D5100).
    I have a D5100 and don't believe ANY Nikon camera is, but all Canon cameras are, capable of performing Exposure Lock in Manual Mode. I WISH I could and I'll tell you why...
    Once you have metered to your desired exposure and dialed in your exposure settings in Manual Mode, say 1/500 @ f/8, you may feel like increasing depth of field to f/22. However, now you're going to ALSO have to adjust your shutter speed, in this case to 1/60. And you'll have to think about this as your meter may be diddling as light shines through trees, etc. and even more so if you're using a metering that's not at zero. This is particularly painful with single-dial cameras like my D5100 where an additional button must be pressed to access aperture adjustment.
    Now, if you could lock exposure value in Manual Mode to 1/500 @ f/8 (as per the example above) and decided to go with f/22 instead, you could just spin the dial until you see f/22 as the aperture figure. The shutter value will adjust accordingly and automatically to 1/60. VERY simple and VERY quick with NO possibility for human error(!).
    Frankly, it is quite amazing to me that Nikon has failed to grasp this very simple concept for SO SO long. It is as ridiculous as Nikon's other shortcoming with flash compensation limited to +1 stop. WHY? And also as totally ridiculous as being in Manual Mode with Auto ISO and not being able to use Exposure Compensation. Well, you can dial in EC, but you won't GET any. You can dial in -5 stops or +5 stops if you like but you will get what the camera considers to be zero. Totally ridiculous that you CAN'T set aperture, shutter speed and compensation with Auto ISO to get your desired result. Nikon REALLY needs to start waking up and firing a bunch of people in their design team(s)... These shortcomings, along with Nikon just getting destroyed in DSLR video by Canon is making me seriously consider selling off my extensive decades-long collection of Nikon cameras and lenses and making the move to Canon once and for all.

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