Exposure Compensation (camera)

[Digital]

When you use exposure compensation you are either increasing or decreasing the exposure usually in incremental steps.
My question is what are you actually affecting in camera, the aperture and/or the shutter?
Any assistance to answer this question will be greatly appreciated.


Bruce

[pnodrog]

It will depend what mode you are using. I tend to use aperture priority at a set ISO so the shutter time will be modified e.g. exposure compensation of -1 will double the shutter speed to reduce the exposure. It should all be explained in your camera manual.

[Digital]

It will depend what mode you are using. I tend to use aperture priority at a set ISO so the shutter time will be modified e.g. exposure compensation of -1 will double the shutter speed to reduce the exposure.

Thank you for your comments. So in shutter priority mode using exposure compensation will in affect increase or decrease the amount of light (aperture) hitting the sensor.
My instruction manual does not explain very clearly regarding exposure compensation IMHO.
What about in manual mode?

Bruce

[Adrian]

1 Aperture priority: aperture chosen based on the subject but your image is too dark. Adding +1 or +2 stops exposure compensation in camera will lighten the image overall. In aperture priority, as we require the aperture to remain the same, the camera will use a slower shutter speed to compensate.
2 Shutter priority: camera opens the aperture, allowing more light to reach the sensor. Reverse applies if image is too light, setting a minus exposure compensation number darkens the image incrementally.
3 Program mode: different manufacturers use different methods but generally they will compensate using a combination of shutter and aperture. In manual mode the camera’s meter indicator will show the correct exposure as being the compensated exposure.

I am aware that current sensor technology is delivering variable and controllable sensitivity, but I believe the above covers the basics. Happy to be corrected by the experts here.

Adrian

[William W]

It may also depend on what camera you are using.
Which is what?

This may be so, if you are using:

• M Mode
• M Mode with Auto ISO
• P Mode with Auto ISO
• P Mode

However, generally, using either Aperture Priority or Shutter Priority, Camera Modes: Exposure Compensation works universally similarly between most camera models and makes.

WW

[pnodrog]

Thank you for your comments. So in shutter priority mode using exposure compensation will in affect increase or decrease the amount of light (aperture) hitting the sensor.
My instruction manual does not explain very clearly regarding exposure compensation IMHO.
What about in manual mode?

Bruce

Correct for shutter propriety but it can get a bit more complicated with any mode when you are using auto ISO.

Manual mode overrides/ignores exposure compensation as what you set is what you get. However I have never tried using manual mode with Auto ISO and the camera manual I have seems to ignore this possibility. Out of curiosity I set my camera to manual and the auto ISO on and as I change either the speed or aperture it seems to be adjusting the ISO to obtain the correct exposure but ignoring the exposure compensation - it is flashing the ISO vigorously and I assume it is a dire warning. It is not a combination of settings I would ever use.

[shreds]

Not teaching you to suck eggs, but this is all explained here:-

https://www.cambridgeincolour.com/tu...a-exposure.htm

In the exposure triangle, you can't alter one element without it affecting the others if you are in any form of auto mode. Exposure compensation only affects auto modes though.

I never set auto ISO as I prefer to control the noise, but use the higher ISOs when applicable in dark situations or for effect.

Aperture priority is widely used, especially for landscapes, but should be avoided like the plague for anything that is moving, as you simply lose control at the expense of maintaining your aperture.

Similarly, shutter priority should never be used where the need to maintain a constant aperture is essential.

I have had people tell me that they only ever use Aperture mode because they had read that was the best, without really ever understanding what they are saying or considering the conditions and type of photograph they are taking.

[William W]

Not teaching you to suck eggs, but this is all explained here:-

https://www.cambridgeincolour.com/tu...a-exposure.htm

I don’t see where Exposure Compensation is directly addressed in that tutorial, but it is here:

https://www.cambridgeincolour.com/tu...e-compensation

Even so, in the above link, Exposure Compensation is described and detailed, mainly in relation to the Metering Modes and also in general terms and it does NOT address the functionality of EC with P Mode or M Mode and the different nuances which might appear when using those Camera Modes and between different camera makes and camera models.


Hence it would benefit to know what camera we specifically are discussing.


WW

[shreds]

Auto & Programme, are both taking creativity and control out of your hands and assigning a preset. Only Manual will let you truly control all the elements.

I can't think of a camera where that is different, so the model or manufacturer is largely irrelevant, other than they tend to call A & S modes by their own designations. (Av, Tv etc).

[chauncey]

I've been confused by that exposure compensation thing because the histogram was all over the place when imported into LR.
Since starting to shoot in manual mode, utilizing Live View's histogram, those problems are a thing of the past.

Technique is: That LV histogram is based on a jpeg rendition of your image so you need to "neutralize" (slide them to the left) all your "picture style" settings. Set-up your LV to display a RGB histogram and blinkies whenever it's opened. Now it's a simple matter to adjust SS, F/stop, and ISO to "push" that histogram to just shy of the right side, a technique referred to as "Exposing To The Right".


Now simply input wanted/needed SS and f/stop and use the ISO to push that histogram to the right,
or...any combination of the three settings.

[HaseebM]

Bruce, best would be to take test images on an object using both + / - and incremental increase / decrease. Perhaps this practical exercise may benefit more than actually trying to understand theoretically, especially on which modes it would suit most.

[Dave Humphries]

Hi Bruce,

The answer in modes other than A (Av) or S (Tv) will vary as Bill and others have mentioned above.

Might I suggest you actually tell us which camera you are wanting advice on?

That way, one of our members with the same model, may be able to provide the information in a more easily digestible fashion than (typically) the table at the back of the manual.

Thanks,



Hi Ian,

Regarding:

Aperture priority is widely used, especially for landscapes, but should be avoided like the plague for anything that is moving, as you simply lose control at the expense of maintaining your aperture.

While this is true, it also the case that if I'm shooting distant wildlife the lens is usually at, or nearly, wide open, so if the meter decides more exposure is needed, the lens may not be able to comply - resulting in under exposed shots, when losing a bit of shutter speed would probably have been more acceptable.

Therefore I do shoot moving things in Aperture priority (or Manual).

The complex relationship between shutter speed and iso being varied by the camera autonomously in Aperture priority is more than my poor brain can cope with, so I don't go there!


I will often switch modes several times a day depending what I am shooting, light angles and what background it is against - and how quickly that might change, based on: is "A" (Av) with some EC likely to get me a more accurate exposure than remaining in M and not guessing the amount of clicks to spin the wheels as the bird, perched in shade, takes off into the sun light? - and in this instance, I might not want f/16 and the background sharp

I guess what I am saying is that there are no hard and fast rules, only guidance for beginners which, as soon as they shoot enough to gain experience, should be disregarded in favour of using what works better for their subjects, camera, etc.

Cheers,

[Digital]

Dave, to answer your question I am asking about the Nikon D300.


Bruce

[William W]

Dave, to answer your question I am asking about the Nikon D300.


Bruce

Thanks for answering.

It’s been several months since I used a D300, but from memory, I am reasonably confident that this list is what will happen in your camera for every possible scenario, where you can initiate Exposure Compensation.

If you are keen to know all of the possibilities you should try them and find out for yourself, you cannot break anything by so doing. Also, as mentioned, I am going on memory so if I have made an error, then I apologize in advance and would appreciate same being drawn to my attention.

Some of the extreme scenarios, when one gets close to ‘the limits’, are unlikely, but are still indeed possible and I have seen some happen and the Photographer's concentration to be thrown into a bit of chaos in an unexpected situation.

A typical scenario which causes concern is in when using a Nikon in Aperture Priority Mode with Auto ISO and the camera ignores the Minimum Shutter Speed for Auto ISO which was selected – this can throw the Photographer’s concentration into a tailspin.

Anyway here’s the list for how EC will work on a Nikon D300:

1. In Aperture Priority Explicit: EC will affect the Shutter Speed. If the limit of Shutter Speed is reached, the camera will allow the shutter to be released and the result will not be suggested exposure.

2. In Aperture Priority with Auto ISO: EC will affect the Shutter Speed – until the Minimum Shutter Speed for Auto ISO (if one is set) is reached then EC will affect the ISO. If the Auto ISO Limit is reached, then the camera will ignore the Minimum Shutter Speed for ISO Limit and will allow the shutter to be released at a Shutter Speed slower than that limit which was set. If both the Minimum Shutter Speed for Auto ISO Limit and the Auto ISO Limit are reached the camera will allow the shutter to be released and the result will not be the suggested exposure.

3. In Shutter Priority Explicit: EC will affect the Aperture. If the limit of Aperture is reached, the camera will allow the shutter to be released and the result will not be the suggested exposure.

4. In Shutter Priority with Auto ISO: will affect the Aperture – until the range of Aperture is reached, then it will affect the ISO. If both the Aperture Limit and the Auto ISO Limit are reached the camera will allow the shutter to be released and the result will not be the suggested exposure. In Shutter Priority Mode the Minimum Shutter Speed for Auto ISO, has no effect.

5. In P Mode Explicit: EC will affect either Aperture OR Shutter Speed OR both as per the parameters of Nikon's program. (* see note 1)

6. In P Mode Explicit with Flexible Program engaged: same as 5, above. (*note 1 also applicable)

7. In P Mode with Auto ISO: EC will affect either Aperture OR Shutter Speed (as per 5 above) AND/OR ISO OR a combination and will also be dependent on the Minimum Shutter Speed for Auto ISO, if one set. (*note 1 also applicable)

8. In P Mode with Auto ISO and Flexible Program engaged: same as 7, above (*note 1 also applicable)

9. In Mode Explicit: EC will affect where the “centre position” of the needle in the Exposure Readout in the viewfinder and it will be adjusted either + or – the amount of EC applied. EC has NO affect on shutter speed Aperture or ISO

10. In M Mode with Auto ISO: EC will affect where the Needle is positioned as above in 9. Also, EC WILL affect the ISO and in so doing Exposure Compensation will function UNTIL by making the Exposure Compensation, the ISO reaches the camera's base ISO and then EC attempts to underexpose or the ISO reaches the maximum ISO and EC attempts to overexpose: in these two cases the EC will stop working at those ISO limits and the Shutter will be allowed to be released. In M Mode the Minimum Shutter Speed for Auto ISO has no effect.

***

*Note 1: P Mode in Nikon DSLRs works slightly differently to Canon’s P Mode functionality and it is with Canon that I am more familiar; suffice to say that it is possible/plausible if you use lenses which transfer FL data to your D300, then the Functionality of P Mode (and thus EC in P Mode) will be slightly different to when you use lenses of the same FL, which do not transmit that FL data.

***

To address some of the generalizations made in other comments in this thread: the devil is actually in all the detail.

Knowing what camera which was being used is indeed necessary to make any detailed comment; generalizations would not be very useful to you, if such generalizations don’t apply to your camera . . .

Certainly the list above will be DIFFERENT, if one is using a Canon DSLR.

Moreover, as well as the list above being different for a Canon DSLR’s; as well as P Mode being slightly different for Canon DSLRs than Nikon DSLR's; Canon DSLR’s have a User Functionality “Safety Shift Av/Tv”, which again places another layer on how EC works at points 1,2 ,3 and 4, in the list above.

There are also other different nuances of EC functionalities between other makes and models of cameras.

Generalizations about the details of any functionality can be just as dangerous as making blanket rules regarding what modes, functions, lenses etc., to use for certain shooting scenarios.

It is far better to understand exactly how each individual camera works - especially the one you are using - and then choose which is the best function to use, for the task that you have at hand.

***

On another related but slightly different topic, in so far as P Mode in your Nikon has the availability of Flexible Program: P Mode is no more or less taking creativity and control out of your hands and assigning a preset than you choosing to use either Shutter Priority or Aperture Priority Modes.

P Mode and the functionality thereof, is the most misunderstood and misrepresented of the Camera Modes.

WW

[Digital]

Thank you so much Bill for your detailed explanation. For the type of photography I do, I mainly use Aperture Priority w/o Auto ISO.

Bruce

[William W]

You're welcome.

I agree that some (most) Camera User Manuals are a bit shy on detail - and that's not just the Nikon ones.

WW

[pnodrog]

Thanks Bill. I was well aware of how it worked in the modes I use but it was interesting to see your summary. Basically it seems if you apply exposure compensation the camera accepts the adjusted value (as centre point of display bar) and does all further processing and exposure display on that adjusted value as per the rules for the mode and ISO settings/method being used.

[William W]

. . .and does all further processing and exposure display on that adjusted value as per the rules for the mode and ISO settings/method being used.

Yes. There is a certain logic to it so if you know the "rules" for your particular camera, you will be in the ballpark as to what to expect to happen.

But I made particular mention of "Aperture Priority with Auto ISO" - as I mentioned I came across the divergence from what I think is 'logic' when I noted what happened to a (Nikon) colleague who was shooting some Sport with me - his (and my) expectation when Nikon introduced Auto ISO and Minimum Shutter Speed in Auto ISO, was that the camera would always obey the Minimum Shutter Speed set by the user.

So I think that a 'light globe went on' in many Nikonian's heads that there was now a good, functional control of the limit of the slowest Shutter Speed the camera will make, when shooting in Aperture Priority Mode. This and the expected bonus, would be useful for many scenarios - some Sports Shooting would be in that group.

Well it works right up to the point it doesn't work, because Nikon's TR&D 'logic' was:
if the camera is running out of ISO, it will be better to ignore the (user applied) Shutter Speed Limit and let the camera make the shot with the 'Correct Exposure' . . . what I guess the Nikon TR&D didn't count on was the Nikon Shooter who's 'logic' was the opposite:

"I have set a shutter speed limit. I expect that to be solid. I now do not have to worry about watching the Shutter Speed when the playing area gets darker"
"I set Auto ISO - and I will set an UPPER limit for ISO - that will be at the noise limit I choose"
"That's very good. I am very happy. Now that I have engaged Auto ISO - I will need to watch is the ISO (not as previously, we would watch the Shutter Speed as the EV drops)"
"And - even better still - I have the bonus of when I get to the limit of ISO and if the EV is still dropping, I can still make shots knowing that I'll be a bit underexposed but I will still be at the necessary Shutter Speed".

Well of course what happened was: the camera allowed the shots to be made and they WERE NOT underexposed, but BLURRED, due to Subject Motion.


WW

[pnodrog]

Maybe Nikon need a camera boss/photographer boss master option setting. When set to photographer boss just do what it is told even if it thinks you are getting it wrong.

P.S. Remind me of a programme I watched recently on air crashes - from memory the pilot tried to stall the plane for a forced crash landing on the top of a pine forest but the auto system cut in and restored power to the engines resulting in far greater damage. Evidently the plane had been upgraded but the flight simulator that he trained on had not and the manufacturers had not informed the airlines of the new "safety feature". There was a way to override the planes response but the very senior pilot was completely unaware of it. He was cleared of any error and was permitted to fly again but never did as he no longer trusted planes.

[William W]

haha! The yes I want one: the master option button . . .

Meanwhile . . . on the other side of the fence . . . Canon "invents" their AUTO ISO . . . [loud applause from Canonytes] . . .

They think, "WOW! I can now do M Mode and Auto ISO - very cool - I can stop motion and also keep shallow DoF and let Auto ISO handle the little ups and downs - I am king" . . .

OK the playing field today is in a lighting variance one end to the other . . . no problem . . . I'll just put my feet up and ride the EC . . .

!*%$#)@*^ . . . where is the EC ?

EC can't be done with a Canon Camera in the configuration: M Mode and Auto ISO - as all the knobs and buttons are already used up and there's none remaining for EC !


WW