100mm 2.8L macro with 6D, shutter too slow in bright sunlight

[Cindy-Clicks]

When shooting with my 100mm macro in Av,  I cannot get a decent shutter speed even in bright sunlight with ISO at 1000.  I don't seem to have this problem with my 70D even though I am shooting at 200mm+.  The 6D is full-frame so it should actually be shooting faster. What is the problem?

[Cindy-Clicks]

These two images were both taken with the 6D ev metering,  f/13, ISO 800.  They were taken seconds apart.  The one on the left was 1/125 sec.  and the one on the right was 1/25 sec.  Why would there be such inconsistancy under the exact same conditions?

[TTMartin]

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@Cindy-Clicks wrote:

These two images were both taken with the 6D ev metering,  f/13, ISO 800.  They were taken seconds apart.  The one on the left was 1/125 sec.  and the one on the right was 1/25 sec.  Why would there be such inconsistancy under the exact same conditions?

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Where you using a flash?

[TTMartin]

With a black background like that your best bet is to spot meter off of something else like a grey card or the grass and use full manual settings. Getting the settings for manual exposure is the only time I recommend using spot metering, as it will often cause the exact situation you have here when used with any of the automated modes.

[ebiggs1]

Cindy-Clicks can you post the photos with the exif left intact?  It is impossibile to tell from the sample you posted.  Except the one on the right is either OOF or has camera movement.

[Cindy-Clicks]

Of course it is going to have camera movement at 1/25.   I just checked the file info and it is exactly as I stated.  If I am shooting like this I should expect consistancy.  I just want to get to the bottom of this because there may be a problem with the lens/camera.

[TTMartin]

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@Cindy-Clicks wrote:

Of course it is going to have camera movement at 1/25.   I just checked the file info and it is exactly as I stated.  If I am shooting like this I should expect consistancy.  I just want to get to the bottom of this because there may be a problem with the lens/camera.

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No problem with the camera.

A black background will confuse almost any metering system.

Evaluative metering is weighted to the active AF point. Just very slight variations in where the camera is pointed can vary the exposure.

With a black background it is best to use full manual exposure settings.

Again, meter off of something other than the black backgound. One of these 12 x 12" Inch (30x30cm) White Balance 18 % Grey Gray Reference Reflector Card with a Carry Bag would be ideal. Or you can meter off of grass, or even the palm of your hand.

[ebiggs1]

"Of course it is going to have camera movement at 1/25.   I just checked the file info and it is exactly as I stated.  If I am shooting like this I should expect consistancy.  I just want to get to the bottom of this because there may be a problem with the lens/camera."

The sample photos do not show a more than 2 stop difference in exposure. 

"These two images were both taken with the 6D ev metering,  f/13, ISO 800."

f13 @ 1/125 with ISO 800

f13 @ 1/25  with ISO 800

 To me anyway they don't.

[Cindy-Clicks]

But it is actually 7 stops.  I took the original files to my local camera shop last night, and they could not provide me with an answer as to why this is happening.  I just want to know if it is problem with the lens or the camera.  This is very expensive equipment to be putting up with this kind of nonsense.  

[ebiggs1]

"But it is actually 7 stops."

Is it?  Let's see. f13 @ 1/125, ISO 800, now f13 @ 1/60, ISO 800 and f13 @ 1/30, ISO 800 = 7-stops?  Maybe you want to check again.

Unless I didn't understand your settings and why I would like to see the actuall exif data.

[TTMartin]

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@Cindy-Clicks wrote:

But it is actually 7 stops.  I took the original files to my local camera shop last night, and they could not provide me with an answer as to why this is happening.  I just want to know if it is problem with the lens or the camera.  This is very expensive equipment to be putting up with this kind of nonsense.  

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1/25 to 1/125 is just over two stops, not 7. And a two stop difference can easily be accounted for by the black background.