Showing results for 
Show  only  | Search instead for 
Did you mean: 

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.




Auto ISO with exposure compensation is now on 1DX and 7DII. The days that ISO was the limiting factor are over. Now there are many scenarios where you want full control over apperture and shutter speed. In those cases having Auto ISO is really helpful to deal with changing light conditions. In older camera's the ISO was too limited to make that usefull, but that has changed. Off course to use that you want exposure compensation to work.

I think it is a shame that this feature has not been released to the 5DIII yet.

As a WildLife photographer who uses the 5D3 sometimes I welcome the option. Let's hope Canon releases a firmware for this.


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


As such, it needs to have Exposure Compensation... But it doesn't on many of the Canon models with Auto ISO. That's why I rarely use it. Maybe some of the newer models have EC on Auto ISO.


I also wouldn't use Auto ISO in combination with Tv, Av or P, either... That would be an auto-auto exposure mode!  No telling what you might get!


Auto ISO also needs user-settable upper and lower limits... Which I believe some of the newer models have.



Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7D(x2), 50D(x3), some other cameras, various lenses & accessories

Whatever you want to call it its just a different way of using it, I don't trust the cameras meter 100 % of the time specially on a small bird in flight.
Auto ISO does currently have upper limit settings on 1dx and 5d3 which I use when photographing wildlife.
When you are in the woods and the subjects are undefined and range from a small moving to a bird in flight we each have our own way of not missing the shot. I find that auto ISO with an acceptable IQ limit makes my work easier and keeper rate up.


Is there firmware which bring 5dMk3 exposure comp. option at M-mode with AutoISO?


Interesting discussion.   For me, manual is a means to control exposure in a different way from either of the semi-auto modes (Tv or Av).  In these latter settings the photographer is making a specific decision about one of the values they want to set - aperture in Av mode, for example. The ISO may, or may not be a fixed value.  However, the camera's metering system may not consider issues with the specifics of a particular subject's tonal values.  For example, shooting in snow, where the sensor will try to make the snow 18% grey: the tone one would normally associate with relatively common images, such as vegetation, but making the snow grey too. In such an event, the use of Exposure Compensation provides a fast means to over-ride the camera's preferred exposure.  This, in itself, might result in a change to the shutter speed, and/or ISO - depending upon the algorithms involved in the camera's metering an control system.

Auto ISO is extremely valuable when one is using one of those modes and one wants to set one variable let's say Aperture, which would then usually commit the camera to choosing a specific shutter speed.  But what if one is shooting in variable lighting conditions and doesn't want the shutter speed to suddenly drop?  Having variable ISO creates a new variable where the algorithm will look at the shutter speed and try to not let it drop too low by providing a variable in ISO value.  In many cameras there is a specific menu feature that allows a user to configure this algorithm: I present this image from the Canon 5DIV manual as an example:
Auto ISo.jpg

In Manual Mode, I would suggest that one is obviously able to control all three settings, ISO, Aperture and S/speed and, by setting two of them, simplify the exposure process, thus have a means to avoid Exposure Compensation by varying the third with its own control. This will still allow the user to introduce changes to exposure that would otherwise be handled by Exposure Compensation. There are times when this is extremely advantageous, I will give an example by Sean Tucker who is a respected street photographer:  I suggest going to timestamp 15:05 for his practical demonstration for his specific situation - which is to shoot light rather than people.  That is quite different from a wildlife photographer, but that simply expresses that photography is made up of many genres, artistic expressions and techniques.
How to Nail Exposure using Manual Mode - Bing video

So, the question is, does using Auto ISO and exposure compensation with Manual mode contribute to the user's flexibility or conflict with their level of control?   I think the answer lies with a foot in each camp.  Let me explain...

Case 1: The user wants total control over the exposure and only use the settings they choose for Shutter speed, ISO and Aperture. Obviously, this would preclude any automated features from the camera, so no auto ISO or Exposure Compensation.  The photographer thus has to be mindful of what the camera meters as correct exposure, and change all the parameters accordingly to compensate for the image's tonal qualities - however, one would normally expect that they would pre-determine at least one of those settings as non-negotiable.

Case 2: The user wants specific values for both aperture and shutter speed, but because of the potential for variations in light, is prepared to allow the ISO to be varied by the camera.  This would provide a good case for using Auto ISO.  However, the camera is still varying that setting by its own metering of the image and, as before with the snow scenario this may not be appropriate.  Being able to use Exposure Compensation would still allow the user to override the camera's metering to introduce more or less light for specific conditions or effects, and within the bounds of the algorithm will change the ISO accordingly, rather than the other two settings. 

I have seen situations where this conflicted with the Auto ISO settings, and then the camera would either flash to indicate that the exposure parameters were invalid, or attempt to change the other two manually-chosen settings, but this is likely a function of the make and model, and is likely to be a relatively rare occurrence.

Whether this is seen as a practical solution is really down to the kinds of conditions under which one shoots, the type of subject and how an individual photographer approaches their control methodology. 

cheers, TREVOR

"The Amount of Misery expands to fill the space available"
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris


As case 2 I would say that ETTR technic is another example why photographers need to compensate exposure at M mode with auto iso turn on. 

Certainly there is an argument for it.  It's interesting how many different methodologies users apply to taking photographs and how that results in a plethora of features within a camera.  As a living fossil, back in the days of film, I had a fixed ISO per roll of film, Av, Tv and M modes.  A couple of autofocus points, and about 2 choices for metering area: Spot or Centre-weighted average.   Learning in that environment shaped how I shoot today.  I use auto ISO a fair bit, but generally use spot metering and focus, with locking of each assigned to buttons on the back of the camera.  For wildlife and people I do use eye tracking though, but I can have various scenarios assigned to the C1-3 buttons.

These days we have hundreds of focus and sensor points.  I don't envy the designers of camera gear as they strive to accede to demands of the market and competition...

cheers, TREVOR

"The Amount of Misery expands to fill the space available"
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris


I am really still not understanding why canon decide to not allowing to compensate at M mode with auto iso turned on, it is simple to add it to firmware. M mode not going to be not manual with EC availability, it will be just easier for some shooting situation, that all.

What is there not too understand.  At the time of the release of teh 5D3, no mid-range camera bodies from the leading manufacturers allowed for exposure compensation in manual shooting modes. Canon began adding the feature to mid-range DSLRs in the late 2010s.

Because it its age, do not expect a firmware update to add the feature.  Sorry.  the camera is what it is.  No doubt the development team was dissolved years ago.

"The right mouse button is your friend."
click here to view the gallery