7D MarkII/100-400 f4.5-5.6 L IS II. Question.

I have a question.
My wife and I have identical Canon 7D Mark II./100-400 f4.5-5.6 L IS II. combo.
She usually asks me about the setting when we shoot. (shoot in manual)
As there was some issue regarding exposure, I compared the two in identical situation.
I found that using the same ISO, aperture, shutter speed, her combo produced brighter image.
In order to equalize it in DPP, I had to increase the brightness adjustment to plus 0.67 on mine.
Is it the sensor in the camera creating this difference?
By the way, all the settings are identical on the two cameras.
Thanks.

First make sure you are using the same metering mode. If they aren't, make that adjustment and then retest.

Assuming that after that they are still different, it is not unusual. Nikon builds in an ability to modify the meter response in 1/6 stops to equalize cameras but I don't believe Canon does. I don't remember ever seeing that. I match my cameras by shooting a gray card and then making all of my cameras put the spike dead center in the histogram. The amount of change that is required changes from 0 to 1 stop even among bodies of the same camera model. Since Canon doesn't give you that option, shoot a gray card with both cameras and then you will see which one is off, then continue to change the exposure (or exposure compensation in an automatic mode) until the two are identical. Once you have them identical you will know how much the actual difference is and you will simply have to calibrate your brains to the difference. Otherwise you could send them both to Canon to match them but that seems extreme.

Thank you E.J.
I just checked again and found everything including the metering mode identical.
I'll try to do what you suggested.

Are you using the same picture style ,just a thought.

Rob.

Lensmaster wrote:Are you using the same picture style ,just a thought.

Rob.

Yes, Rob. Everything is identical including the picture style.

I haven't shot identical camera and lens combos at identical settings to know what's going on. But I assume both are shooting in the same AF mode, say Ai-servo or some other AF mode. You are not shooting shoulder to shoulder and framing the image the exact same way from the same angle, etc. However, if your images are consistently less bright during the shoot, I am not sure what may be the cause.

OntPhoto wrote:I haven't shot identical camera and lens combos at identical settings to know what's going on. But I assume both are shooting in the same AF mode, say Ai-servo or some other AF mode. You are not shooting shoulder to shoulder and framing the image the exact same way from the same angle, etc. However, if your images are consistently less bright during the shoot, I am not sure what may be the cause.

I think what's going on is that both Nikon and Canon only require their meters to be within + or - one stop of accurate when they leave the factory and they don't calibrate each one to a standard.  Even way back when I was shooting the 1D and 1Ds bodies, and also on my 2 1D Mk IIn bodies, the metering was quite different on some of the bodies.  At least Nikon gives the user a way to fix it in 1/6 stop increments.

EJ - If the OP is shooting in manual mode, setting the shutter speed, aperture and ISO the same in both cameras and then taking an image with both (and assuming the light hasn't changed) resulting in one image being darker than the other. How can that be a metering problem? He states "in order to equalize it in DPP, I had to increase the brightness adjustment to plus 0.67 on mine."

I also believe that you can adjust the metering on Canon bodies, well at least on a 1Dx and 5D Mark III. Under Custom Functions - AE Mircoadjustment. You can adjust metering in ⅛ stop increments.

Andy Trowbridge wrote:EJ - If the OP is shooting in manual mode, setting the shutter speed, aperture and ISO the same in both cameras and then taking an image with both (and assuming the light hasn't changed) resulting in one image being darker than the other. How can that be a metering problem?  He states "in order to equalize it in DPP, I had to increase the brightness adjustment to plus 0.67 on mine."

I also believe that you can adjust the metering on Canon bodies, well at least on a 1Dx and 5D Mark III.  Under Custom Functions - AE Mircoadjustment.  You can adjust metering in ⅛ stop increments.

Good point Andy!  they should produce the same image in that scenario.  I missed the part about manually setting the two exposures to be the same and then having them turn out 2/3 of a stop different.  Then I would ask if they are using identical lenses, which they are.  If not, one might have a lot more transmission loss than the other.  If yes, as is the case here, then perhaps one lens has a sticky aperture diaphragm so reversing the lenses on the two cameras should reverse the problem.  Or if they are both shooting at f/7.1 or f/8 perhaps one of the lenses isn't stoping down at all and is therefore shooting wide open all the time even though the in camera indication is that it is stopped down.

Thanks on pointing me to the way to adjust it on a Canon body but is that only for Automatic Exposure - at least that's what the name indicates and why I missed it since I never shoot in any automatic exposure modes.  What about metering the same scene differently?  For example one camera meters the gray card at 2/3 of a stop different than the other.  Will that adjustment correct this difference in the two meters or does it only bias the automatic exposure calculations?  If it changes the way a scene is metered by biasing it then it is definitely misnamed and it should be called Meter Microadjustment

If you are shooting together or shooting both cameras I would equal them out or calibrate them to each other for consistency. And I agree with EJ as if it works this way it's not just an AE adjustment - it's a direct meter bias adjustment so AE is the wrong language.

E.J. Peiker wrote:

Andy Trowbridge wrote:EJ - If the OP is shooting in manual mode, setting the shutter speed, aperture and ISO the same in both cameras and then taking an image with both (and assuming the light hasn't changed) resulting in one image being darker than the other. How can that be a metering problem?  He states "in order to equalize it in DPP, I had to increase the brightness adjustment to plus 0.67 on mine."

I also believe that you can adjust the metering on Canon bodies, well at least on a 1Dx and 5D Mark III.  Under Custom Functions - AE Mircoadjustment.  You can adjust metering in ⅛ stop increments.

Good point Andy!  they should produce the same image in that scenario.  I missed the part about manually setting the two exposures to be the same and then having them turn out 2/3 of a stop different.  Then I would ask if they are using identical lenses, which they are.  If not, one might have a lot more transmission loss than the other.  If yes, as is the case here, then perhaps one lens has a sticky aperture diaphragm so reversing the lenses on the two cameras should reverse the problem.  Or if they are both shooting at f/7.1 or f/8 perhaps one of the lenses isn't stoping down at all and is therefore shooting wide open all the time even though the in camera indication is that it is stopped down.

Thanks on pointing me to the way to adjust it on a Canon body but is that only for Automatic Exposure - at least that's what the name indicates and why I missed it since I never shoot in any automatic exposure modes.  What about metering the same scene differently?  For example one camera meters the gray card at 2/3 of a stop different than the other.  Will that adjustment correct this difference in the two meters or does it only bias the automatic exposure calculations?  If it changes the way a scene is metered by biasing it then it is definitely misnamed and it should be called Meter Microadjustment

It works the same as on Nikon.  It's poorly named and even the ´Info´ description is a little misleading but it will bias the metered reading in manual mode not just in the automatic exposures modes.  

However, I just doubled checked my 5D Mark III and can't find that custom function on that camera, so maybe its just a custom function only on the 1D Series cameras or at least the 1DX.

"Andy Trowbridge wrote: It works the same as on Nikon.  It's poorly named and even the ´Info´ description is a little misleading but it will bias the metered reading in manual mode not just in the automatic exposures modes."

However, I just doubled checked my 5D Mark III and can't find that custom function on that camera, so maybe its just a custom function only on the 1D Series cameras or at least the 1DX.

Thanks for checking and your answer.

Could it be that her camera has the Auto Lighting Optimizer (ALO) turned on, while it is off on your camera?
Since you state that you are using DPP and since that parameter is used by DPP, this could account
for the difference in brightness, even if all the exposure parameters are the same.

Luis Villablanca wrote:Could it be that her camera has the Auto Lighting Optimizer (ALO) turned on, while it is off on your camera?
Since you state that you are using DPP and since that parameter is used by DPP, this could account
for the difference in brightness, even if all the exposure parameters are the same.

Yes, that could do exactly that!

I checked all the setting again: they were identical.
Manual exposure.
Tv 1/200 s
AV 5.6
ISO 1000
Partial metering.
Focal length: 400 mm
Picture Style: Standard.
White Balance: Auto
Color Space: sRGB.
Auto Lighting Optimizer was off on both cameras.
If I remember correct the 1D M4 had the AE Micro adjustment available (no longer have the camera) but neither 7D nor 5DM3  has it.
Next time I'll switch the lenses an find out how it works.

Hmm, the mystery deepens. Yes, please let us know if it follows the body or the lens. My money is on the body

It looks like the camera is the one that has a difference.
I used my lens and changed the cameras.
My camera produced darker image at identical setting.
I did it at f 5.6 and f 7.1.
I compared the images in DPP.
I had to move the slider to plus 0.5-0.67 to get equal brightness of the two images.
(The correction would be somewhere between 0.50-0.67)
Thanks for all the comments.
It is too bad that the AE Micro Adjustment is not available on the camera.

Then the next thing to check is with a long exposure. Say a 1 second exposure. If the difference is gone with a long exposure then the camera that is exposing less may have a sticky shutter. Any stickiness in the shutter would be eliminated by a very long exposure but would be a significant part of the exposure on a fast shutter speed.

I used 1 second at ISO 100 f 29 on both.
Cable release, mirror luck up, view finder covered up.
Result: brightness of the files were identical.
What is your suggestion E.J.
Should I take my camera to Canon Services or just live with the condition exists.

It could be a sticky or slow shutter then. The underexposing camera may need service.