EOS 5D Mark III (focusing and dark photos)

[aaronmadler]

Hello,

I have two questions -

1: When I choose Auto - The camera decides to choose randomly, whichever of the 61 auto focus points it selects and sometimes the photos are in focus and sometimes they are not.  How do I choose within Auto, how to specifically select the center of the camera as the focus?

2: When I choose P - The camera takes dark (underexposed) photos - (80/3.2/100).  I have compared this with A (Auto) and the camera uses the correct settings for a great photo - (80/2.8/1250).  Why does the camera take such dark photos and how do I correct it?

Thank you,

Aaron M. Adler

[Waddizzle · Accepted solution]

1.  The whole point of Green [A] mode is allow the camera to behave like a simple "point and shoot" camera.  Therefore, allowing the user to pick an AF point is not an available option.  The camera will tend to focus on the nearest object to the camera.

2.  Use your quick menu to check and set your ISO to AUTO.  It sounds like it has been manually dialed in as 100.  Also, you should see a difference in the viewfinder'sexposure meter between the two circumstances that you described.  You want the exposure meter to read zero, dead center.

3.  You need to take some time to read the instruction manual.

[Waddizzle · Accepted solution]

1.  The whole point of Green [A] mode is allow the camera to behave like a simple "point and shoot" camera.  Therefore, allowing the user to pick an AF point is not an available option.  The camera will tend to focus on the nearest object to the camera.

2.  Use your quick menu to check and set your ISO to AUTO.  It sounds like it has been manually dialed in as 100.  Also, you should see a difference in the viewfinder'sexposure meter between the two circumstances that you described.  You want the exposure meter to read zero, dead center.

3.  You need to take some time to read the instruction manual.

[aaronmadler]

Hello Waddizzle,

Even though I've been looking at You Tube videos and Googling online, your explanation was simple, to the point and exactly what I was looking for.

Thank you,

Aaron

[TCampbell · Accepted solution]

As Waddizzle says... full 'Auto' is designed to be more or less foolproof (or as foolproof as it can try to make it) and to do that the camera doesn't like you control much - you decide where to point it and when to press the shutter button... it decides everything else.

When multiple focus points are available (when you don't force the camera to use a specific focus point) then the camera will generally choose the point which is able to lock focus on the nearest subject.   E.g. suppose you are taking a photo of someone (they are your intended subject) but there is something closer in the scene ... a plant perhaps... and there are focus points covering the areas with both your intended subject as well as that plant.  The camera will focus on the plant because it is closer.  When you let the camera automatically choose the focus point, you'll want to watch for this.

When you use "Program" mode, the camera will choose the same exposure it would have chosen when using "Auto" mode EXCEPT you can override things.  

You can use a feature called "Program Shift".  Iif you roll the main selection dial -- this is the dial near the shutter button -- you'll see it trading stops of shutter speed for stops of aperture to balance the light to get an equivalent exposure.)  

You also have the ability to do "exposure compensation"  If you use the rear dial while looking through the camera, you'll notice the exposure needle in the viewfinder is moving left or right -- indicating that you have asked the camera to deliberately under-expose or over-expose the shot (and this setting sticks until you return it back to the center position.)

My guess is that you rolled the rear-dial (even if by accident) and the camera has now set some exposure compensation to underexpose.  It will continue to do that until you return it to the center position.  Just point the camera at something while looking through the viewfinder (in Program mode of course), half-press the shutter button to wake-up the metering system, then roll the rear dial to center the digital needle you see in the viewfinder.  This information is also displayed on the rear LCD screen if you have the shooting information displayed (you can change what the camera displays on the rear LCD screen so depending on the selection you may not see this information.)

[aaronmadler]

Hello Tim,

I didn't want to respond until I got home tonight to use the camera to figure out what you stated and now I see exactly what you mean.  Thank you again for describing everything succinctly.  I now realize what my issues were and you correctly explained it exactly with your excellent comments!  Thank you very much.

Kind regards,

Aaron