Program EOS 70D to hold exposure

[moonlight33]

On the Canon EOS 70D, there is a button one can press to hold the exposure and then reframe the shot. It is unbearably difficult, because often I need to hold the focal point as well and it is hard not to accidentally press the shutter, etc.  When I utilized a Canon film camera, I could use the focal point to hold the focus AND the exposure point together by simply pressing the shutter halfway, then re-framing.  Please can someone help me to find a way to program this camera to always sync the exposure with the focal point so I do not have to press the little button (which is hard to not mess up due to there being 2 other little buttons in the same area)? Thank you so much, this is how I shoot all of my shots, it is not possible to work quickly without a way to program this.

[Waddizzle]

“ The 1D series allows exposure to be assigned to the focus point being used, avoiding need to focus-recompose. “

You may have Spot AF in mind.  Only 1D series bodies allowed any AF point to be used in Spot AF mode, as well as meter at any selected Spot AF point.

[Anonymous]

You want metering start and AF start for the shutter button. If you select the trash can while programing the buttons, it will reset all the buttons back to default.

[jrhoffman75]

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@moonlight33 wrote:

Thank you so much to everyone for your responses. I am reviewing and testing out these suggestions and will be back for a follow-up.  Yes, I am trying to connect my auto focus spot (with one shot) to my metering, 100% of the time, without having to find that tiny little button on the back.  I already tried the Metering Start setting as suggested, but this stopped my ability to auto-focus.  Will be continuing to review all of the helpful links.

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Check your manual and read about the AE Lock (*) button. It has a 4 second timer (I believe) so you don't need multiple fingers. 

[moonlight33]

Hi, thank you for the response. I did go through the steps..in Operation/Others I proceeded to Custom Controls (#4), then moved to the Shutter butt. half-press Metering and AF start screen, then selected the icon on the upper left, then had the screen "Shutter butt. half-press" and selected the first one on the left with the "Metering and AF start", then hit "Set/OK. Then exited out of these menus by hitting the Menu option.  I then tried to shoot, but the same thing occurs, that the camera will not hold my exposure along with the focal point, when I reframe the shot. Of course, I am still holding the shutter button down halfway. I'd be thankful for any further suggestions to solve this.  Using the little button on the back is not possible with the type of photography I do.  I'm not shooting nature scenes and need to work quickly. Thank you so much for the help.

[Waddizzle]

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@moonlight33 wrote:

Thank you so much to everyone for your responses. I am reviewing and testing out these suggestions and will be back for a follow-up.  Yes, I am trying to connect my auto focus spot (with one shot) to my metering, 100% of the time, without having to find that tiny little button on the back.  I already tried the Metering Start setting as suggested, but this stopped my ability to auto-focus.  Will be continuing to review all of the helpful links.

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Reset custom control programming to factory defaults.  Use Evaluative Metering mode, which is the factory default and everything should fall into place.

Use just a single AF point.  The center AF point is the most accurate.  Binding exposure can work with any single AF point.  

However, Spot AF only works with the center AF point.  I only use Spot AF on a tripod.  It meters an area that is much larger than AF point.  Notice how the Spot AF circle shown in the above illustration touches at least 5 metering points.  I almost never use Spot Metering because of this.

Use One Shot AF because when it locks focus it will also lock the exposure.

[moonlight33]

Hello Waddizzle, thank you for the info. Re: evaluative, is this is my only option to avoid utilizing the exposure lock? I'm learning this camera system, but have been working with partial or spot metering in my attempts to recreate the way I used to work with my Canon film camera. I shoot mostly black & white backlit (natural light) with models/people as my subjects (or journalism) in AV mode. I want to control the way the light appears for the creative work. The only workaround I can come up with, is to use evaluative along with exposure compensation, to allow more light in (or less).  This is frustrating for circumstances in which I would like to have a very black background and need spot metering and need to work quickly.  Is there any other way for me to link the partial metering with the focal point and hold that exposure when reframing? And if not, I've read that evaluative metering still concentrates on the focal point, but I wouldn't think it would be as accurate as the partial metering. Thank you for your help!

[Waddizzle]

“ This is frustrating for circumstances in which I would like to have a very black background and need spot metering and need to work quickly.  Is there any other way for me to link the partial metering with the focal point and hold that exposure when reframing? And if not, I've read that evaluative metering still concentrates on the focal point, but I wouldn't think it would be as accurate as the partial metering. Thank you for your help! “

It almost sounds like you are asking about a different shooting scenario now.  Achieving very white or very dark backgrounds is best achieved in post-processing, not in the camera.

I have thought that you wanted to meter the scene at the selected AF point.  This is very easy to do because this is the default behavior for the camera when you use One Shot AF combined with 1 pt aF.. Select any AF point you wish.  The center AF point is the most sensitive and accurate.  This only requires the use Shutter Button, a half-press to lock focus and exposure followed by a full press to take the shot.

If you wish to focus here while metering over there, then that is a different scenario that will likely necessitate the use of the [AE LOCK] button as John suggested.  This means that you could be returning to a dual control button shooting scenario.

Could you describe exactly which end result you are trying to achieve?  Are you looking to do both?

[Waddizzle]

There are three basic scenarios when it comes to recomposing shots.

1 - Focus, recompose, followed by metering and taking the shot.

2 - Metering, recompose, followed by focusing and taking the shot.

3 - Metering and focusing, recompose, followed by taking the shot.

This last scenario is what I have been describing and can be easily achieved using only the Shutter Button.  The first two scenarios are probably dual control button shooting scenarios.

Spot AF is more subtle and complex that many realize.  It does not help or allow the camera and lens to focus more accurately.  Spot AF allows you acquire your subject more accurately.  

Similarly, Spot Metering does not allow the camera to meter a scene more accurately.  Metering takes place over a significantly larger area than many may realize.  Unlike Evaluative Metering, Spot Metering completely ignores the rest of the scene.

The only scenarios when I may use Spot AF and Spot Metering is shooting from a tripod, 

[Anonymous]

I would go back and check the shutter button programming again. Perhaps the change wasn't saved. You can also use the trash can button while in the custom button programming screen to reset all the buttons and controls back to default.

[moonlight33]

I am in need of #3. I wish to use partial metering most often (and periodically spot metering). I choose the focal/metering point simultaneously and then reframe and shoot.  I do not re-focus.  I need one step only. Thanks!