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Exposure Compensation : un outil indispensable pour contrôler l'exposition de votre appareil photo



And if you cannot find such a button, there might be a dial on the top or the back of the camera that goes from a negative value to a positive value, such as -3 to +3, with small increments in between. If you are having a hard time finding the exposure compensation button / dial, please check your camera manual for details.




Exposure Compensation



Once you make adjustments to exposure compensation, the +- EV values will be shown in the LCD and the EVF. If you cannot see those values after making changes, you might need to turn on informational overlays from the camera menu.


Although I have stated above that metering systems on cameras standardize on middle gray, many of the modern cameras now come with sophisticated metering systems that are capable of recognizing scenes based on pre-loaded data and make necessary adjustments to the exposure, essentially minimizing the use of the exposure compensation feature.


For my type of photography I have never used exposure compensation. I shoot everything manual which is much easier! I select the aperture I want and adjust the shutter speed and viceversa. If a scene is challenging, I close or open the aperture (or shutter) to obtain the perfect exposure.


My question concerns metering on a dark football helmet and jersey in football stadium at night. I took some photos from a middle school football game last night using my Nikon D7100, cropped sensor camera using a Nikkor 70-300 Zoom lens. I tried shooting my pics with shutter priority, Zoomed to the 400 where fStop Is f3.5 and I wanted my speed at 1000 to freeze movement, iso 400. And my pics were all underexposed ? Since I was shooting from the stands on the stadium I was not exactly sure where to meter my camera. I could not set any exposure compensation for my situation. I finally resorted to using manual mode and I used less shutter speed and a lot of ISO, 2000 to get the my pictures to brighten ?


Camera manufacturers have determined that most scenes will average out to a middle gray tone, often referred to as 18% gray. And your camera uses this 18% gray as its exposure benchmark; it analyzes the scene, then sets the exposure to perfectly match that gray value.


Ask yourself: Does the result look good? Or is it too dark (in need of positive exposure compensation) or too light (in need of negative exposure compensation)? Based on your evaluation, you can make changes to the exposure compensation value, then start again.


So find the button and press it. As you do, turn the main dial of your camera right or left, which will reduce or boost the exposure compensation value. Each click of the dial will usually change exposure settings by a third of a stop.


Exposure compensation is a technique for adjusting the exposure indicated by a photographic exposure meter, in consideration of factors that may cause the indicated exposure to result in a less-than-optimal image. Factors considered may include unusual lighting distribution, variations within a camera system, filters, non-standard processing, or intended underexposure or overexposure. Cinematographers may also apply exposure compensation for changes in shutter angle or film speed (as exposure index), among other factors.


Many digital cameras have a display setting and possibly a physical dial whereby the photographer can set the camera to either over or under expose the subject by up to three f-stops (f-numbers) in 1/3 stop intervals. Each number on the scale (1,2,3) represents one f-stop, decreasing the exposure by one f-stop will halve the amount of light reaching the sensor. The dots in between the numbers represent 1/3 of an f-stop.[1]


In photography, some cameras include exposure compensation as a feature to allow the user to adjust the automatically calculated exposure. Compensation can be either positive (additional exposure) or negative (reduced exposure), and is frequently available in third- or half-step, less commonly in full steps or even quarter-step[# 1] increments,[# 2] usually up to two or three steps in either direction; a few film and some digital cameras allow a greater range of up to four,[# 1] five[# 3][# 4] or even six[# 1] steps in both directions. Camera exposure compensation is commonly stated in terms of EV units; 1 EV is equal to one exposure step (or stop), corresponding to a doubling of exposure.


Exposure can be adjusted by changing either the lens aperture or the exposure time; which one is changed usually depends on the camera's exposure mode. If the mode is aperture priority, exposure compensation changes the exposure time; if the mode is shutter priority, the aperture is changed. If a flash is being used, some cameras will adjust flash output as well.


Many modern cameras incorporate metering systems that measure scene contrast as well as average luminance, and employ sophisticated algorithms to infer the appropriate exposure from these data. In scenes with very unusual lighting, however, these metering systems sometimes cannot match the judgment of a skilled photographer, so exposure compensation still may be needed.[2]


An early application of exposure compensation was the Zone System developed by Ansel Adams and Fred Archer.[3] Although the Zone System has sometimes been regarded as complex, the basic concept is quite simple: render dark objects as dark and light objects as light, according to the photographer's visualization. Developed for black-and-white film, the Zone System divided luminance[# 5] into 11 zones, with Zone 0 representing pure black and Zone X (10) representing pure white. The meter indication would place whatever was metered on Zone V (5), a medium gray. The tonal range of color negative film is slightly less than that of black-and-white film, and the tonal range of color reversal film and digital sensors even less; accordingly, there are fewer zones between pure black and pure white. The meter indication, however, remains Zone V.


The Zone System is a very specialized form of exposure compensation, and is used most effectively when metering individual scene elements, such as a sunlit rock or the bark of a tree in shade. Many cameras incorporate narrow-angle spot meters to facilitate such measurements. Because of the limited tonal range, an exposure compensation range of 2 EV is often sufficient for using the Zone System with color film and digital sensors.


This unique statute was designed to serve as an expeditious, low-cost alternative to litigation. Significantly, RECA does not require claimants to establish causation. Rather, claimants qualify for compensation by establishing the diagnosis of a listed compensable disease after working or residing in a designated location for a specific period of time.


The dates of coverage are from January 1, 1942, through December 31, 1971. The Act requires the employee to have worked in a covered uranium mine for at least one year, or have been exposed to 40 or more working level months of radiation while employed in a uranium mine, during this covered period. Alternatively, an employee may have worked in a covered uranium mill, or in the transport of uranium or vanadium-uranium ore from a mine or mill, for at least one year during the covered period. To be eligible for compensation, a claimant must establish both uranium industry employment that meets these statutory requirements and a subsequent diagnosis of a specified compensable disease.


Although residents of the Four Corners Region (Utah, Colorado, New Mexico, and Arizona) have filed the majority of RECA claims, the program has awarded compensation to individuals residing in each state, as well as several foreign countries. The claimant population includes many Native American tribes. The Program has visited more than a dozen reservations to meet with tribal leaders and assist tribe members filing RECA claims.


The picture above shows an underexposed image. The camera settings did not do a good job of exposing the scenery. With the Exposure Compensation function, we can easily increase the exposure value by dialing it up a bit by +1 EV to brighten up the image


As for Manual Mode and Auto Mode, the Exposure Compensation will not work during these two modes. In Manual Mode, you have to set your own values manually (Aperture, Shutter Speed, and ISO) so the Exposure Compensation will also be a manual entry. In Auto Mode, the camera does everything for you so there is no control for overexposure.


Most cameras will give you an Exposure Compensation range between -3EV and +3EV. This provides photographers plenty of control over exposure, being able to step up or down in increments of 1/3 EV. We also noticed more advanced cameras with a range between -5EV to +5EV, allowing much more freedom to lighten or darken a photo.


More often than not, your camera will correctly expose your photos. However, in some situations, your camera is unable to capture the correct exposure meter which happens in certain settings like a snowy landscape or a nighttime scene.


Another related technique is something called Exposure Bracketing, or AEB. When you set your camera on AEB, it essentially takes multiple photos in a row, each one with different exposures. The first image is at normal exposure, the second one is underexposed, and the last one is overexposed.


You can use Exposure Bracketing in Manual Mode by adjusting the Exposure Compensation, ISO, or shutter speed manually. You may also use the AEB or automatic feature on your camera for exposure bracketing. Each camera will differ but it will typically be labeled as AEB, Exposure Bracketing, or EB in the menu settings.


Exposure compensation can adjust shutter speed, aperture, ISO, or a combination of the three depending on the exposure mode selected. The thing to remember is that exposure meters, whether hand held on in the camera, want to adjust the exposure for an 18% (or 12% or similar depending on who you ask or where you look) gray. What does that mean? Well, it means that the average scene wants to reflect 18% of the light available. It is a good average. However, how much light does a snowy hill reflect? A lot more than 18%. So, if you expose snow, without benefit of exposure compensation, you end up with grey snow. Now, you all know you have done that and seen grey snow; Right? 2ff7e9595c


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