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5DIII Auto ISO in Manual + exposure compensation


Hi everyone,

You can use Exposure Compensation in Av, Tv, or P Mode to slightly adjust the exposure that the camera is selecting. In Av mode, you fix Av and ISO, the camera selects the shutter speed with the correction from the overcompensation.


In M mode with Auto ISO, I really don't understand why the Exposure Compensation is not present. In M mode, I would like to fix apperture, shutter speed, and use Auto ISO to do the last fine tuning, but here I can't select Exposure Compensation. 


I guess this comes from the days where you had to fix the ISO in the low 100 to 400, but now you have so much more room to play with this, having Exposure Compensation with Auto ISO would really help me. I now usually manually set the ISO to overexpose and check the histogram, but camera could help me with slight changes in lighting if I could use Auto ISO.




At the time the of the 5D3 generation, some other manufacturers DID offer this feature in similarly priced bodies.

However, you are right that the camera is what it is and nothing is likely to change now. It's still a great body, but this feature would have made it better for some, and seeing other cameras have the feature for a similar price was at the time, both frustrating and a little baffling - though Canon at the time had a reputation for being feature poor.

Still enjoy my 5D3 though it looks very rough these days - it's still going strong. You learn to work around things, and at the time the sensor was pretty forgiving, though, again, behind the competition in this regard - which makes the lack of this feature even more frustrating for those who would appreciate it.


Auto  ISO in M mode is no longer manual... it's just anther auto exposure mode.

The above statement is accurate, but it completely misses the point.  

Canon bodies were missing basic function found in all bodes by its competitors.  One would expect the camera to be to control all legs of the Exposure Triangle.  One would also expect the camera to control a combination of any two legs, or any single leg of the Exposure Triangle.

Canon bodies were coming up short when it came to allowing the camera to control any single leg of the exposure triangle.  Competitors allowed for their cameras to only control ISO with EC, which is an operating mode that was previously unavailable on Canon bodies. The easiest way to add this functionality is to allow for the use of ISO Auto in Manual shooting mode.  

Does allowing ISO Auto mean the camera in no longer in Manual shooting mode?  Yes, it does mean the camera is no longer in full Manual shooting mode.  So, what.  In Tv or Av modes, you can set a fixed ISO value, or you can dial in ISO Auto with EC being available in either case.  So, why take away EC when you use ISO Auto in M mode?

If the camera is in any automatic mode, then it should be allow for Exposure Compensation, and the Canon bodies were not permitting this type of functionality.  So, Canon eventually began to add  it to their new DSLR releases.

 I am not aware of any DSLR model that had it added via a firmware update.  If it did not have it from the factory, then that was that.

"The right mouse button is your friend."

You may not be aware, but the reason for this post originally was the update that Canon did for the 1DX. As it is merely a calculation, it is something that could easily be added by firmware.

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