apersson850 wrote in post #11520996
If you are just going to chase the exposure meter in M mode, then you can just as well use an automatic mode. The benefit of the M mode is that you get consistent exposure when the light is the same, but the reflectivity of the subject is not.
Chasing the meter is just a more cumbersome way of doing what the camera can do for you.
You should not need to use "trial and error". That can get very frustrating.
Instead just choose any of the auto modes and you'll get the exact same result as you will using the M mode and changing the aperture and shutter until the "needle" on the scale is zeroed out. The reason for this is that you are using the camera's internal meter in both cases... so are going to end up the same place.
If you truly want to start using M and avoiding some of the errors that are inherent in any reflective meter, I suggest you buy a handheld incidence meter. That will give you more accurate exposures once you learn to use it properly. (It's easy!)
The errors of a reflective meter come from the fact that the meter is trying to measure the light being reflected off your subject. And since subject tonalities vary wildly, the camera can only set itself based upon what it sees in front of it... Or if shooting in M mode, the meter read out you are getting from the camera to manually select both aperture and shutter speed will also give the exact same errors.
The camera's reflective meter doesn't know if you are photographing a black bear in a coal mine or a polar bear in a blizzard, so all it can do is try to render everything the same neutral gray. That works much of the time, but it also gives a lot of incorrect readings and settings.
Reread Peterson's book a couple times. It gives you guidance how to anticipate and work around the meter's inherent errors. In any of the auto modes (Av, Tv, P) that's mostly done with Exposure Compensation. But you can also use other tricks such as AE Lock, Spot Metering, etc.
However, using a separate handheld incidence meter simply eliminates all these errors. It measures the strength of light falling onto the subject, rather than what's being reflected off of it. So long as light is relatively steady, this type of meter won't change, your camera settings can and should remain the same, and you can start thinking in terms of selecting the most appropriate aperture for depth of field or the most appropriate shutter speed for subject motion rather than spending all your time and mental energy trying to correct for reflective metering errors.
You can test this yourself, to get a better idea what I'm talking about. Set your camera to Av or Tv, go outside on a normal day then point the camera at anything and pan 180 degrees, while keeping your eye to the viewfinder and observing the shutter speed (if Av) or aperture (if Tv is selected).... Avoid going in and out of shadows... just pan across a variety of subjects under the same light... A parking lot full of cars in full sunlight (or on an evenly cloudy day) with the sun to your back is a good example. The camera's settings vary wildly, don't they? That's because the cars are all different colors and tonalities, not because the lighting has changed. Exposure often varies up and down by a stop or two or more. Yet the lighting and the necessary settings actually aren't changing at all!
Now, if you use an incidence meter, per the instructions, you will see very little variance as you measure the light falling onto the subject. You can simply set the camera to M, select the meter's recommended exposure settings and start shooting.... Every single shot will be very close to the ideal exposure and won't vary up and down, the way it will using the camera's internal, reflective meter and any of the auto exposure modes (or using the internal meter to take a reading and setting the shot parameters yourself). There is no need for exposure compensation. You can tweak exposure a little, say if you decide a dark subject would look a little better slightly lighter, or a light subject is too light and you want to preserve a little more detail. But you'll be manually overriding the exposure by changing the aperture size or shutter speed, probably in small, 1/3 stop increments instead or much larger compensations usually needed with other methods of metering.
The inconvenience of doing this is that you have to carry around and use an additional meter, and there is additional cost for that meter. You also have to be certain you are standing and metering in the same lighting that's falling onto your subject. You don't want to meter while standing in the shade under a tree while photographing cows that are standing out in full sun in the middle of a field. The example of an incidence meter I linked to above happens to be a flash meter, so in addition to ambient light it can also be used to measure studio strobes and portable flash, for accurate exposures with those. There are less expensive (and more expensive) incidence meters available. Many of the lower priced ones cannot measure the very short duration of flash and strobe light.
On a bright sunny day I often don't pull out the meter at all. I just use M and the "Sunny 16 Rule" to set my exposure. That rule says that on a normally sunlit day, with the subject in full sun, it will be accurate if you set the ISO, then select a shutter speed that is the reciprocal of the ISO (ISO 400 would use 1/400 shutter speed, for example), and then set the aperture to f16. If I am shooting the shaded side of my subject, I open up to f11. If I need a higher shutter speed I can open up further to f8 and set the shutter to 1/800 for the shady side, or 1/1600 for the sunny side of the subject. If I want a slower shutter speed, I can reduce ISO or use a larger aperture, or a little of both.
If it's an overcast day (which I prefer, less deep shadows) I can use a "Cloudy 11 rule"... I.e., everything the same except I start out with the aperture open one additional stop: at f11. This also works for "normal" shadow areas on a sunny day.
A really dark and stormy day or deeper shade might need another stop.... f8. Actually I think most people might be surprised how often they can set exposure pretty darned well by eye, once they start doing it and getting a little practice.
Unless lighting changes significantly I'll just use the histogram to tweak my settings a little, as needed in the course of the day. This is one of the most valuable tools that DSLRs have given us. We didn't have histograms when we were shooting film! However, I've learned to not trust the image review/playback to judge exposure accuracy. The little LCD on the camera is too heavily influenced by ambient light to give an accurate guide to exposure... But the histogram gives you accurate feedback, once you know how to read and interpret it.
At first glance, all this might appear to go against what Bryan Peterson tells you to do in his book. However, at it's core it really is the same thing... You have three exposure parameters you need to control: ISO, aperture size, and shutter speed. The methodologies in "Understanding Exposure" are designed to allow accurate use of the camera's internal meter, which at times you will still need to do. Imagine if you will, that black bear I mentioned earlier, dashing from one coal mine to another coal mine, in a blizzard! Or perhaps the polar bear running in and out of coal mines and blizzards. In those cases - and many other real life ones - you will have to rely upon the camera's internal metering and exposure systems to rapidly make the adjustments for you. So I strongly recommend studying the book until those techniques become second nature for you, too. The use of either an incidence meter or the Sunny 16 Rule (and its variants) aren't covered in the Bryan's book, because it's focus is on how to use the meter you already have, right there in your camera. And "Understanding Exposure" goes further in some other ways, explaining and demonstrating a variety of special situations where you might choose different lenses, accessories and/or camera settings to get the results you want.
Most experienced photographers will actually use different metering and exposure setting methods in different situations, or might use one method to confirm the settings they are seeing recommended by another method. It pays off to know how and when to use each technique, since you will be faced with a wide variety of shooting situations and will want to be able to figure out accurate exposures to use quickly in each case. Once you have learned how to do this, you can literally pick up and shoot with virtually any camera made and get good results, will only need to deal with the small nuances of how different models and makes arrive at the same ends.
Unfortunately, the answer to your original question is "Yes", the exposure level indicator on your camera can be manually manipulated or it can be determined and set by the camera. Either one... Not one or the other. I would suggest for now, lacking the manual and time to study and learn other exposure methods, use the camera's auto settings (Av, Tv or P) and just start down the path of understanding and learning to control the camera to get the results you want. If you look at a scene and it's overall tonality is pretty even, trust the metering system to give you a good exposure. If a subject is unusually light tonality, add some + Exposure Compensation. If it's unusually dark, dial in some - EC. If you are out shooting a snowy scene and most of the world is white, for example, you might need to dial in + one or as much as two full stops EC to prevent "blowing out" highlight detail. Or if you are photographing an overall dark object such as details on an old, black train locomotive, you might need to dial in - one or even two full stops to maintain good shadow detail.
Check the histogram in each case and try to prevent it from "spiking" strongly at either the righthand (highlight) or lefthand (shadow) side of the scale. In a scene with tonalities that average out to neutral gray, you'll see a "hill" in the middle of the histogram that tapers off to either side, when exposing correctly. If your subject's tonality is mostly one extreme or the other, you'll might see a "dogpile" of data at one end of the scale or the other, just watch out that it doesn't crowd right up against and start to get clipped off the end of the scale, to keep your exposures correct. Reset the camera (either with Exposure Compensation if using any of the auto modes, or by changing aperture size or shutter speed if in M mode), fine tuning your exposure settings, and reshoot anything that looks to be exceeding the histogram scale.
It can also help to shoot RAW. This allows for more adjustments later, on your computer screen at home where ambient lighting is probably a lot more consistent and reliable than when viewing the image on the camera's little LCD screen. If you adjust a RAW file and make a print that you are unhappy with, you can go back and readjust the file. JPEGs right from the camera don't allow for nearly as much adjustment after the fact. And if you fine tune one, then are unhappy with the printed results, you might not be able to recover and fully readjust the JPEG.