What Overrides What?

I seem to have stumbled into a tarpit, said the mastodon.

Apparently the Great Fujifilm X-Series Exposure Compensation (EC) Dial Controversy has spilled into TOP, and lots of people have opinions about what knob or dial should do what. And I spoke too fast.

It's really a question of what should do what. All I can do is explain what I would expect: 

I conceive of EC controls as being primarily for the purpose of correcting metering where metered values might be wrong (i.e, when you know from experience the meter is being "fooled"); so EC is really most convenient to use with autoexposure modes only.

In manual mode, the shutter speed and the aperture are measured values and should not shift from the values you set. So in Manual mode with Auto ISO, I would expect the EC dial to affect the ISO. 

Which it doesn't.

Why? Well, here's one possible explanation. I've just spent a bit of time fiddling with the camera. In practice, with the X-T1 set to Manual exposure and Auto ISO, the camera doesn't seem to adjust very well. I would need to use it more to be sure, but my guess is that letting the camera adjust precise exposure via Auto ISO isn't very practical with this camera. It's not a method of shooting I've ever used, so I don't really know much about shooting this way. My guess is that this is why EC is disabled in Manual mode/Auto ISO—because Fuji knows it doesn't work all that well and they'd prefer you not use the camera that way.

So I guess I'd take back what I said previously. EC is there primarily for use in correcting incorrect meter readings in Aperture-priority autoexposure or Shutter-priority autoexposure, and really shouldn't be used in Manual exposure mode—regardless of the ISO setting.

Does that make sense?—Or is it just useless to struggle when you're in a tarpit?

Mike
(Thanks to Mike Steinbach)

Tech. Ed. Ctein adds: "As to how exposure compensation works, it's actually pretty simple if you step back a level. It changes the exposure the camera makes according to the exposure mode you have the camera operating in. For example, if you're in aperture priority mode, dialing in exposure compensation changes the shutter speed (the same way a changing light level would). If you're in shutter priority mode, it changes the aperture. If you're in program mode, it may change one, the other, or both—it'll depend upon the algorithm the camera uses for trading off aperture against shutter speed.

Me, personally, I use it all the time. I just about never do manual metering. My preferred mode is aperture priority (keeping a watchful eye to make sure the shutter speed is within a tolerable range). I have a very good internal sense of how the meter in the camera will respond to different subject/lighting conditions. When I see one that I think is likely to introduce an exposure error, I'll dial in some exposure compensation before I even make an exposure. I'm pretty good at guessing it right. And, of course, with instant previews and histograms and shadow/highlight callouts, it's really easy to see if I did guess right. Considerably more than half the time, my first guess at the exposure compensation will be satisfactory. In the cases where it's not, a second exposure will be right on.

For me, this is both faster and more intuitive than messing around with manual readings and adjustments. In fact, my camera almost never comes off of aperture priority, with me manually tweaking the exposure with exposure compensation.

Of course everyone's mileage will differ. This is just mine.

Now, it makes sense that exposure compensation wouldn't work when you're in manual mode, because how is the poor camera supposed to know what to do? Should it adjust the aperture? Should it adjust the shutter speed? Should it split the difference?  It's going to guess wrong more than half the time. Which sorta flies in the face of manual control.

Of course, it feels weird to have a "mechanical" dial that doesn't work, sometimes, but  what you going to do?

I don't have any idea how "Auto ISO" actually works, because I never use that mode, but I'll bet you it creates a similar conundrum—that exposure compensation would result in the camera doing nonintuitive things.

Mike replies: Like you, I habitually use Aperture-priority and Exposure Compensation. However, when you say, "I have a very good internal sense of how the meter in the camera will respond to different subject/lighting conditions," that's a very important point, and it's crucial for using EC.

EC compensates for scenes where the meter makes errors. Therefore it's necessary to have a good sense of where the meter will make errors for you to be able to apply the correction.

It's something I wrote about years ago with the Nikon FA and N8008, the first cameras with evaluative metering (Nikon called it "Matrix Metering" at the time, although I don't know if they still do). The point then was that it was harder to know what the meter was doing and therefore more difficult to apply EC effectively. In the early days of evaluative metering I tended to ignore it and continue to use averaging metering because it was easier to correct. Later, when evaluative metering got so much better, I gradually switched to trusting it—and used EC less often.

Original contents copyright 2014 by Michael C. Johnston and/or the bylined author. All Rights Reserved. Links in this post may be to our affiliates; sales through affiliate links may benefit this site.

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(To see all the comments, click on the "Comments" link below.)
Featured Comments from:

Dave Parry: "Surely in Manual mode the EC dial should just effect the meter reading? Hence why on many manual cameras the EC dial is built into the ISO dial."

Mike replies: Took me a little while, but I've come around to agreeing with this. EC is primarily a metering adjustment. So, in an ideal camera, with all three values (ISO, aperture, shutter) set on hard values (i.e., nothing on automatic), the EC should still be applied to the meter readout, yes.

Comments

[Howard]

Mike, I'm in the tar pit, but a different end, because I don't understand the hoopla regarding the EC. In manual, the top ISO is set to the desired and then adjusts in 1/3 increments, as well, the f stop adjusts in 1/3 increments. Then throw in a dial for shutter control, and another for meter control How much control is required? To para phrase, you can please some all the time and all most of the time, but never all, all of the time.

[Mark Scholey]

See, now I'd disagree completely about EC adjusting the ISO, especially as many people have hang-ups about moving away from low ISOs.

I have no problem with EC not working in manual, as if the camera is metering incorrectly while you are in manual, it's a better practice for you, the photographer, to adjust either the shutter speed or aperture as you see fit; i.e. adjust which one best suits the shooting condition you are in. You're in manual, so you're clearly happy with 'taking control' therefore it makes sense that you adjust which one of those controls suits the condition.

In aperture priority using EC affects the shutter speed and vice-versa. This makes perfect sense as you are choosing which of those factors is more important for you to control. If you go fully auto (or P for Pro) you're relinquishing the decision making so when you override the metering it makes sense again that the camera chooses.

To assign the EC dial to adjust ISO only under certain conditions is counter-intuitive from an interface usability stand point. It makes the function of the dial confusing *especially* as you already have an iso dial.

[Right, and this is what I was objecting to initially about the X-T1. The idea of having a dial that is operable sometimes and not other times is not ideal. Of course it's something that, once known, can be accommodated to, too. --Mike]

[Ken James]

Thanks Mike, this is Great. I have spent quite a bit of time trying to figure how people use this EC control in digital and there is nothing I can find written on the subject. I have never used EC. If shooting in snow, extreme example, I am in manual, which is usually the case anyway, unless I do not care about the parameters. On the Fuji, I would like to see that big knob on the right be ISO, that is what I am excited about about digital cameras. My F3 has a EC thingy, but I never touched it. It was slow to engage anyway.

[Michael B.]

Sounds like a great control system, and I love the directness of labelled dials as a concept. But that's certainly a flaw. No excuses! Samsung NX, as far as I remember, has the same issue.

My Pentax K-30 works seamlessly in this style of shooting. Pentax really gets it with this camera as far as letting you control parameters in whatever way you choose.

[Michael Tapes]

Hi Mike,

Forgetting the camera for a second and thinking only about discussing the operation, I believe the problem is in the use of the term 'Manual Exposure', as you used above:
"...really shouldn't be used in 'Manual Exposure' mode..."

There are 2 manual exposure modes in many of today's camera.
-manual exposure with Auto ISO
-manual exposure (as we know and love it..fixed ISO)

In fact this applies to Av and Tv modes as well. Each of those has an Auto-ISO variant and a Fixed ISO variant. So we have to figure out how to discuss all of these modes (6 in all).

Somehow we have to inform the discussion properly. In AV and Tv modes whether we know that the photographer manually set either the Aperture (Av) of the Shutter speed (Tv). For example, in the case of Av, Auto ISO only affects how whether the camera's metering system will change the Shutter Speed only, or the ISO only or both, depending upon the Auto-ISO settings in the camera. EC applies a user dialed bias into the camera's metering system as it should, allowing the photographer to "modify" how the metering system reacts to the light by a brain calculated amount.

In the case of manual exposure (as we have known it), EC does not and should not have any effect because the camera's metering system is not affecting the exposure, it is only displaying it's results in the little +/- display graph. UNLESS the camera has Auto-ISO as part of the camera's metering system. In that case, if the camera allows Auto-ISO to be used in "manual exposure" mode, then the EC should and must allow the photographer to dial in an EC to affect the amount of exposure to be modified as he/she sees fit (the purpose of EC).

So in the end...

1 - if the camera has an Auto-ISO system that is able to be turned on in Manual exposure mode, we MUST state whether Auto-ISO is engaged or not when we specify "manual exposure".

2 - if the camera allows Auto-ISO to be used with Manual Exposure, they MUST allow the photographer to modify (bias) the exposure via EC. That is the nature of how an Auto Exposure system works in modern camera, and there is no reason not for this to be the case. Simple dial in a "0" EC if one does not want EC to affect Manual Exposure with Auto-ISO set.

As a suggestion for discussion, maybe we could call the 3 modes with and without Auto-Iso as follows:

Av
Tv
M

Avi
Tvi
Mi

..or some alternate scheme.

best.

Michael

[JG]

EC is there primarily for use in correcting incorrect meter readings in Aperture-priority autoexposure or Shutter-priority autoexposure, and really shouldn't be used in Manual exposure mode—regardless of the ISO setting.

Sure, but what if you switch to manual mode (say, because the +/- 2-stop EC adjustment range provided by the EC dial on the X-Pro1 isn't enough) and want to further tweak the shutter speed by an additional third-stop without letting auto-ISO do its thing?

As Fuji has things setup, you have to do so using buttons and then you can only tweak it 2/3-stop max, at which point you have to go back to the shutter speed dial and twirl it to the next highest or lowest shutter speed and push the buttons some more. Not only is this a clumsier procedure that requires more time, but it also requires you to actually look at the camera while pushing the buttons, which is a nuisance when the camera is mounted on a tripod.

However, if the EC dial was still operational, you could adjust the shutter speed you set manually by +/- 2 seconds in third-stop increments by feel alone, by counting the clicks every third stop, and never have to look away from your subject while doing so.

Not only would this method be consistent with the method that is used with the camera in its auto-exposure mode -- certainly no harm in that, eh? -- but it also requires less time to perform and offers a great range of adjustment to boot.

I can't speak for others (of whom there appears to be a significant number), but this is the reason why I believe that Fuji's chosen approach of disabling the EC dial in manual mode is wrong-headed. If there is actually an advantage to doing things Fuji's way, then I don't see it.

That said, if Fuji had seen fit to provide the X-Pro1 and X100S' EC dials with a three-stop range instead of two (as it's done with its later models), this would be a non-issue for me 90% of the time. As it is, though, when I am photographing at night, I often find myself needing more than two stops of exposure adjustment and either have to switch to manual mode (for shorter exposures) or to "bulb" or "T" mode (for exposures longer than 1", but still within the 30-second auto-exposure range.) Because I am often photographing from total darkness, being able to operate these two cameras by feel alone was actually a major factor in my decision to buy them. YMMV!

[Speed]

I've always thought that Exposure Compensation should be controlled using a slide operated by the photographer's thumb with a detent in the middle (none). But slides are a manufacturing nightmare.

[Bryan Willman]

Hmmm...

Well, I've shot a bunch of frames in aperature priority autoexposure with auto ISO and a minimum shutter speed set. This in effect gives me F/what-I-choose at 1/60 (it's dark) and whatever ISO should make that work.

Hopefully I'll get to download the frames soon and will try to report back.

But it seemed to work fine when shooting and chimping.

[Mark Cotter]

Intriguing thread. I've never had a problem with EC and using it as it's always been there on my DSLRs. I've just got my OM1 off the shelf to remind myself of the old manual days: ah, yes, set the shutter speed and the aperture and then adjust one or other to ensure I get the exposure I want. So, then back to my X-T1 and X Pro 1 to have a look at how I use them. Ah, yes, if I use aperture priority or shutter priority, I'm inclined to use EC to fine tune things but both my cameras are in manual mode - where they seem to have been since I bought I them. As both these cameras look and behave like 'old' cameras, I've turned into the 'old' photographer.

[Dale]

HA! this is interesting and to be honest, the vast majority of "pros" that I know, use it the way you do Mike, Aperture preferred with EC as needed, actually quite a few leave the EC at -1 as a starting point.
For me other than AF which has only been since turning 60 and realizing my eyes dont work so well. I am both a complete manual and avid amateur, (amateur in that I am in it for fun and not money.... any idea how much this stuff costs??? I refuse to consider that in any rational business model:-)So back to the beginning... for now, since speed is rarely a concern, EC is a wasted dial.... but like AF it could change soon...

[John Krumm]

After yesterday's post I fiddled with my EM-1 some more and figured out I can come frustratingly close to what I want in manual mode. The lever in the 2 position (in one option) allows the iso to be adjusted by the rear dial, so I can lock shutter speed and aperture and use iso like an EV adjustment. But.... it throws up a big iso guide in the viewfinder every time I touch the dial, so no go for me.

[Rex Lechat]

I'm not sure I'm really adding anything new to the discussion here, but here's another way of looking at it. In any of the automatic modes, EC corrects the exposure settings made by the meter. In manual mode, the exposure settings are made by the photographer. It seems odd that I would set an exposure using aperture, shutter speed, and ISO, and then "correct" myself using yet another dial.

[Tony Roberts]

Most of the time most of us can guestimate a good exposure. When EVs don't correlate with our experience, especially with dim or backlit subjects, then meters have their roles. Not one to trust the camera meters of old, for years I used a Minolta III that gave excellent ambient readings. I could then judge the reflectivity and make a good exposure. Nowadays, the camera meters are first-rate and trustworthy in nearly all tough situations. But one thing to consider I've found is that EC increments are not all created equal: plus or minus one increment doesn't necessarily equate to one zone of EV. This all needs testing and of course, it's time well spent.

[BrianW]

Fuji X cameras have some funny ideas about exposure. For example, in the X100 (and others) the exp comp dial becomes ineffective once exposure has been locked, rather than adjusting relative to the locked reading. (I believe this may have finally been corrected in the X-E2).

But my biggest complaint is that the live histogram does not do anything useful in manual mode. I believe that this is still true for all X cameras, even after many firmware updates.

Manual mode with real shutter-speed dials plus a good live histogram should be a dream to work with. Sony and Canon understand how the histogram should work, why can't Fuji?

I write this as someone who loves his X100 dearly, but still struggles to forgive these issues.

[Michael Perini]

Mike,
The consensus about Fuji Cameras seems to be that they have usually gotten these control things generally 'right', from an experienced photographer POV. No camera will ever be perfect for everyone. Compared to the Nikon implementation on the Df where is some situations the dials are wrong, Fuji looks better.
Some of this depends on one's history. If you came from a world of all manual film cameras, your first brush with automation was probably Aperture Priority. Canon & Nikon had tons of non automatic lenses so an electronic shutter tied to the meter was AUTO.
Most serious photographers I know tend to use Aperture priority most.
If I'm using Flash, (studio or field) I'm in manual.
As you & ctein have pointed out, EC works best for those able to make educated guesses based on knowing how the meter responds. (Although I do recall a polaroid camera with a Lighter/Darker knob)
Auto iso is something of a new phenomenon. It has not been a parameter that most folks have been comfortable with allowing it to 'float'. Personally I try to keep iso's near base level.
But as cameras have improved, the range of iso's that produce 'truly good enough' results on some cameras has widened significantly. So my sensibilities may be a bit old fashioned.
This becomes more true as cameras allow Auto iso Ranges to be specified. In that sense iso has become closer to a true dynamically adjustable third variable in determining exposure. (even though some of us tend not to think of it in that way)
In which case your point about being able to choose what function (s) EC controls becomes very important.
Personally, I am comfortable with the way you describe the Fuji working. I can bump the ISO a stop as fast as I can adjust EC, it's just a different button.

[Shaun]

I always thought of EC as a way to correct what the camera thinks is the correct exposure, but only in aperture or shutter priority modes. There is that other thingy, the histogram, which should help indicate when to use EC in A or T, and what changes are to be made to the aperture or shutter speed in manual mode.

[MarkB]

Manual mode should be "manual," as in, you do it all yourself, dummy. Now, if only there was a strange, hybrid TAv mode with ISO suitably effected by EC... oh yeah, which camera brand has that? ;)

[Mark St. John]

Pentax (Ricoh) got this EC stuff correct. Eg their "TAv" mode is great. Also, I like that I can shoot in Av with the shutter preference to "fast"; the camera works out something like 2X the focal length for the minimum shutter speed and after that the camera starts ramping up the ISO. Really useful.

[Rory]

Shooting a D3, auto ISO is not something I've ever really used, though I do change ISO regularly on the fly. I'm about 90% in manual mode, finding it easier to get similar exposure from shot to shot that way. Sometimes I will switch to Aperture priority, and then I will use the EV compensation control. So to me it makes sense that the EC dial doesn't work in manual mode - I always expect the camera to be hard set in this mode, and not affected by the compensation dial. Seems like a non debate in my book!

[Moose]

I don't have as broad experience of the metering behavior of various brands of cameras. with three Canon DSLRs, several Canon and a Samsung P&S and several Oly and Panny ILCs.

But that experience is clear. All my cameras are set as default to -2/3 EV. That way, if I just grab, point and shoot, the chance of clipped highlights is minimal.

Heavy overcast or other low contrast brings EV up; red/orange/yellow flowers in sun bring it down further. I can't believe how many images I see on the web where flower colors are obviously off and/or that where there should be details of tonal variation, there is just a big blob of a single color. This can happen with bright colors of any kind, but is worst with flowers, so Mike probably doesn't have to consider it. \;~)>

I realize reading this that I have no idea how my cameras act in Manual Mode with Auto ISO. That seems an oxymoron to me. I'm a Aperture preferred mode guy, too. In those few situations where I use Manual, I have a specific goal, ISO is a part of it, and also set manually. Should I call it 3D Manual? All the cameras I use have an exposure guide available in Manual that lets me simply set my variation from the meter's opinion.

Most days, I understand Ctein's descriptions of they way camera makers determine 'correct' exposure/ISOs. I understand why they would want most images to come out balanced looking for most, and especially casual, users. Nevertheless, the basic nature of all digital sensor systems I have used is that they clip highlights all too easily.

So I am very willing, happy even, to get an overall underexposed looking shot where the highlights just kiss the top of the histogram, and adjust midtones and shadows in post.

I don't think this varies in spirit from the Zone System or many other practices of film photographers - adjust exposure and processing to compensate for weaknesses in the sensor system/film and get the results desired.

Moose

[MHMG]

Mike wrote: "So in Manual mode with Auto ISO, I would expect the EC dial to affect the ISO.

Which it doesn't.

Why? Well, here's one possible explanation. I've just spent a bit of time fiddling with the camera. In practice, with the X-T1 set to Manual exposure and Auto ISO, the camera doesn't seem to adjust very well."

Well, as usual Mike, you've arrived at the crux of the matter and at what Fuji engineers should aspire to fix in a future firmware update. Like Ctein and yourself, I've long shot primarily in Aperture priority mode with the EC dialed in to alter the meter's normal reading for situations like strong backlighting. Much easier than manual mode when you get the hang of it. However, I never had a camera (until the D800E) which offered Auto ISO, so I couldn't envision wanting yet a another mode configuration at my disposal.

Now that digital cameras have auto ISO, a full "auto manual" mode should be a piece of cake ;-). Set both the shutter speed and aperture you want, and let the camera determine the correct ISO speed necessary, for example ISO 935 if that's what it takes to satisfy the meter's estimate of the scene exposure. Then the photographer has to keep an eye on the ISO gain, but this can usually be capped in the menu settings to an ISO which is acceptable on noise level to meet the photographer's needs. And with that kind of a "auto manual" setup, the EC dial is just as important as it is with traditional aperture priority mode. So, Fuji engineers just need to work on a little more programming to smooth the auto ISO ramping.

I'd probably use that kind of auto manual mode a lot in low light indoor conditions where both aperture and shutter speed are more critical to me than a given ISO, and in fact such an auto manual mode ensures that the camera and not me will be seeking out the lowest possible ISO setting necessary to satisfy the desired depth of field and subject/camera movement.

Only catch would be when the auto ISO hits its limit. Then I'd suggest the engineers let the shutter speed and aperture settings deviate as if in program mode, backing down both gradually if more exposure is still needed when the auto ISO maxed out.

There, not so hard is it ? ;-). Well, maybe a tricky piece of programming, but I think Fuji engineers are up to the challenge!

[Gary Mortensen]

I read of these X-T1 issues with interest, since I'm waiting for B&H to ship me one (I know they're currently closed). Speaking of using the X-T1 manually, I hope one feature has been changed since my X100 was designed: when shooting in manual, the histogram display is always that of an "ideal" exposure. That is, it has no relation to the shutter/aperture/ISO you're actually using. This "behavior" used to generate much angst on the various Fuji forums; has it been changed (I hope)?

[Patrick]

I'm struggling to understand this:

"Dave Parry: "Surely in Manual mode the EC dial should just effect the meter reading? Hence why on many manual cameras the EC dial is built into the ISO dial."

Mike replies: Took me a little while, but I've come around to agreeing with this. EC is primarily a metering adjustment. So, in an ideal camera, with all three values (ISO, aperture, shutter) set on hard values (i.e., nothing on automatic), the EC should still be applied to the meter readout, yes."

Does that mean, do you both mean, that if you set +1 stop of EC, the meter should show you this as what it interprets as overexposure (in my Nikon, by three bars lighting up to the left of the "correct" meter reading), or do you mean that you adjust your settings to achieve the "correct" meter reading - the one in the middle, no bars either side - but have to remember that you have set +1 on the EC dial? [I have to say it pains me both to be so dense and to care so much about what you both mean! :-)]

Would it be arcane to suggest that the display shows the symbol for EC struck through or crossed out when you are in entirely manual mode thereby indicating that it is disabled?

[stephen]

If you already have a dial that adjusts iso, why would you want to use a different dial (called ec, or whatever,) to adjust iso? This issue is part of why "automatic" cameras can be more difficult to use than manual cameras. So.... call me silly, but it strikes me that we should call the easier to use camera "automatic," and the very difficult to understand camera, manual. Is this confusing?

[steve]

Mike,

there is a simple reason why EC doesn't work in manual exposure mode. It may sound strange but it is because of flash.

Note that when in manual mode (setting aperture and shutter speed manually) the visualisation on the LCD and in the EVF is optimized for viewing, but it does NOT represent the actual exposure.
For example, you can set something like 1/2000 and f/16, and you can still see through EVF and
on the LCD as normal, but when you take a picture it will be severly underexposed.

On some but not all X cameras this can be switched off, to allow exposure preview on manual mode. However, then you cannot work with flash!!

what does this have to do with EC? Well, the histrogramm is tied to the exposure preview on the LCD. Thus, you will see that the histrogram does not shift in manual mode (in effect it does not show the actual exposure!).
so EC is not useful.

[Tom Kwas]

Mike, you said it..."evaluative metering" has thrown quite a monkey wrench into even the "guestimation nudge" of the f/stop ring. Back in the day, when you could really tell what a meter was reading, you could automatically compensate for stuff when what you were looking at seemed too "black cat in a coal bin" or "dove in a snow storm", now there's no telling what the meters doing, so good luck. I used to be an expert, especially with my old Miranda Sensorex, of opening it up a little...all gone now...

[Michael Martin-Morgan]

Unless it's a closely guarded patent thing, by this time in the game why on earth only Pentax have realized you can have Tav on a digital camera beats me ...

[David Paterson]

EC is just a way of interfering manually in what would otherwise be totally auto-exposure, be it aperture or shutter priority. If you are in manual mode, it does nothing whatsoever. It does NOT change the meter-reading - as has been suggested - and if in auto-iso it does not change the iso value. In manual, all it does is tell you that, when you go back to using auto-exposure, there is a non-zero value set for exposure compensation.

I'm pretty sure most camera manuals will make this abundantly clear.

[Dennis]

Here's how I look at it. The meter calculates a target EV. Depends on the scene and the metering mode you choose. EC should change that target EV. So if you meter a scene in which you know the meter is likely to be fooled, you compensate. Simple as that.

Then you have your three parameters which get you to that EV and various exposure modes you can use. Aside from manual, every other exposure mode adjusts something to get you to the target EV. So if you dial in EC, you should get to that corrected EV.

Practically speaking, I chose a Nikon D7000 over the Canon 7D when I switched from Sony 2.5 years ago for two reasons: (1) a quiet shutter option (without switching to live view) and (2) Auto ISO in M mode that works with EC. I shoot ice hockey. Lighting levels vary across the rink, due to uneven lighting and the presence of a bank of windows at one end of the rink. I want 1/500s and f/2.8 and the ISO can be whatever the ISO needs to be. But I need exposure compensation to account for all that ice. (Colors of uniforms vary from white to black so spot metering isn't a very viable option).

For slower shooting, I much prefer to meter, lock and recompose if there's something in the scene that's likely to throw off the meter. But for some shooting, EC is the way to go.

The final argument is simply this. Compared to wifi and in camera HDR and stitching, this stuff is stupid simple. 1960s. A kid can program this years before programming 101. Cameras today feature all sorts of features to make them appeal to almost anyone imaginable, but then fall flat on basics like this. If a handful of photographers can use it, throw it in !

[Hugh Crawford]

On my Sony NEX my most used mode is to set the f:stop on a manual focus lens with it's aperture ring, set the camera to shutter prefered auto exposure mode, and ISO to auto. This achieves what it sounds like people are asking for. You can't do that with the native lenses as far as I know. Pentax has a mode like this. Perhaps there is a patent issue , because people keep clamoring for it and other manufacturers don't implement it even though it would cost close to nothing.

[Jim Simmons]

Please let BrianW know that Fuji fixed the histogram-doesn't-work-in-manual issue some time ago.

[Nicolas Dade]

How "Auto ISO" seems to work on the camera I am most familiar with, the Panasonic GF1, seems simple. And from quick experiments in the past I believe the Olympus EPL-2 and Nikon D3200 work similarly. It seems to me the "Auto ISO" feature keeps the ISO setting at the lowest [best] value unless doing so would result in too slow a shutter speed. If that is the case, Auto ISO raises the ISO to keep the shutter speed reasonable, up to a configured maximum ISO value. Past this point dimmer subjects will result in slower shutter speeds.

The value considered "too slow" a shutter speed is the faster of 1/<35m equiv lens focal length> and a minimum value. The minimum seems to be fixed at 1/30th on the GF1, but IIRC was configurable on the D3200. With a zoom lens attached the "too slow" shutter speed tracks the zoom position. I don't recall whether stabilization is taken into account but it could be reasonable to do so.

For example, if we use a lens with an equivalent focal length of 50mm and a maximum aperture of 1/1.4, and a body with a minimum ISO of 100 and configure a maximum ISO of 800, enable "Auto ISO", put the camera in A mode, select f/something (doesn't matter what), and photograph progressively dimmer scenes, we would get something like this series of exposure selections:

1/4000th ISO 100 # very bright
1/2000th ISO 100 # half as bright
1/1000th ISO 100
...
1/100th ISO 100
1/50th ISO 100 # at S limit
1/50th ISO 200 # ISO raised
1/50th ISO 400
1/50th ISO 800 # at ISO limit
1/25th ISO 800 # S lowered
1/10th ISO 800
...
1 sec ISO 800

---------

"Auto ISO" in M mode means the ISO value is adjusted within its bounds to achieve the exposure the camera normally selects (scene measurement +/- exposure compensation).

---------

IMO the way the A and S modes adjust only shutter speed and aperture and not the ISO on digital cameras seems like an imitation of a limitation of film.

[Michael Perini]

Stephen said:
"If you already have a dial that adjusts iso, why would you want to use a different dial (called ec, or whatever,) to adjust iso? This issue is part of why "automatic" cameras can be more difficult to use than manual cameras. So.... call me silly, but it strikes me that we should call the easier to use camera "automatic," and the very difficult to understand camera, manual. Is this confusing?"

The part about Manual can be mich simpler, rings very true to me.
The more things that 'float' the harder it is to know exactly where you are quickly with all the variables.
So on a practical basis I tend to shoot most in Aperture Priority, riding EC, second most in Manual, especially when locking down an ambient light exposure and using flash, In the Studio always manual.
I do understand the logic of allowing floating ISO to be a third automatic adjustment (and if it works for you that's great) and I use it myself with one camera a Canon S95 where it is always set at 28mm equiv. f/2.0 AV mode and auto iso 80-400.

But for paying jobs it makes more sense to me to know where everything is set, and if I need to change ISO (or anything else) it's just a different button.
If it's not locked down, you don't really know where it is.The fewer things you have to look at the more you can concentrate on the subject. Perhaps this just comes from learning the trade on manual cameras and in studios.
I'm certainly not suggesting this is either the Right or only way to work.
I may be showing my age but as I read this and other discussions about automation and working methods, increasingly I find myself thinking "ok, but why would a person want the camera to decide that'
Perhaps it's also the kinds of work I do where a good deal is on a tripod with T/S lenses etc.
It also shows how much of the Digital UI is (unnecessarily ??) held over from film. It workd fine for me, but perhaps a total rethink would have been better in the long run.
Interesting

[Michael Steinbach]

Having scanned the posting it seems Michael Tapes has it pretty much nailed.

What we have is a manual mode that is not truly manual. By definition manual mode puts total control into the photographers hands, but with auto ISO the camera retains a part of that control. So you are not in manual mode but an ASP mode (Aperture/Shutter Priority) when auto ISO is engaged.

The point of which is obvious, maintain a specific DOF and action stoping shutter speed, while the correct EV is achieved by the cameras metering system (right or wrong). By allowing EC, the photographer can adjust based on their knowledge of the scene and understanding of the cameras interpretation. Without EC, the auto ISO function is effectively cut off at the knees.

Would this odd implementation stop me from purchasing the XT1? No. I too am a aperture priority user, but it does hobble an otherwise excellent camera with strange behavior trait.

[Will]

My first day with my XE-1, I was shooting a portrait of a friend. I wanted shallow depth of field so I was close to wide open (2/3 down, iirc). I wanted a sharp image with no trace of shake-blur, so I was at 1/250 or 1/500. I was in auto ISO for ease. The image came up dark at iso400, so I dialed EC to plus one, and nothing happened, as you well know. You may have come to agree with this, but I do not.

I was in auto ISO because I did not want to keep digging into the menu to change my ISO. I was also comfortable with any ISO value below the 1600 maximum I'd set. I specified aperture and shutter values I wanted, but I wanted it a stop brighter. There was room to achieve that with ISO. Why not have the EC dial adjust ISO to achieve this?

The problem with the way it works is it means that in manual mode but auto ISO, you cannot have any exposure other than what the camera gives you. Changes in shutter or aperture are zeroed out by the ISO. You have a dark image and chase your tail attempting to fix it. It means I don't use manual exposure as often as I'd like.

An ISO dial would fix this for me by making it trivial to set my own ISO. But in the meantime, the EC dial should work within the preset limits of ISO when in auto ISO but manual exposure. Just my opinion.