Being able to correctly make Exposure Compensation (EC) changes during photography is one way you can improve your general subject exposure.  The EC controls on your camera allow you to either add light, or subtract light from the exposure in order to protect important elements in the image.  Its important to understand that the camera's meter creates an "average" or "middle-toned" exposure of your subject - 18% gray to be exact - half way between black and white.  However, what do you do if your subject - or an important part of your subject - is not middle-toned?

     You always expose for the highlights of your subject.  The reason you do this is that if you over-expose the highlights - the lighter areas of your subject - there is nothing there in the digital file, nothing to darken and get back - no detail at all.    Most D-SLR cameras will have "blinkies" or "marching ants" circling this area of the image on the rear screen after taking the image.  If this happens, start to reduce light in the exposure by using the EC controls on top of the camera.  Continue to reduce the light until the "blinkies" stop appearing.  It is easier to lighten a dark image, than darken an overexposed area in the image.

     Find the EC controls on the top of your D-SLR body.  It is usually a button that has the following icon imprinted on it:  +/-    By pushing this down, and turning the control wheel or dial, you can alter the exposure.  In most digital photography applications this will almost always be to the negative (-) side because you are protecting the highlights (bright areas) of the image from overexposing.  Depending on your camera maker, the compensation control effects the exposure in either half-stop or third-stop increments.  I have my camera set for half-stop increments because third-stop increments is not enough to alter the exposure by much.

     Here are some examples of EC changes:

The white feathers on the bald eagle's heads was an important part of the image - overexpose them and the images are worthless.  In this image I dialed in a -1 EC, taking out one full stop of light in order to protect those feathers.      I commonly shoot nature images with the compensation set to -.5 EC all the time.  It seems that shooting the images at 0 EC always leads to slightly light images - test your own camera and see what you like best.  Just remember to reset the EC to 0 when you start doing other types of photography, like people.
Another shot of bald eagles, this time the backlit "silhouette" effect at sunset was the most important part of the image for me.   I also didn't want to have the sun "white-out" in the image.  Again, I'm subtracting light to make the exposure of the image is as I see it.  The EC for this image was also -1.      Now I shot this image both ways and without the EC of -1 detail began to show up in the distant mountains, the sun was more washed out, and I lost a lot of the color of the sunset.
Like the previous eagles image, the important part of this image to me was the shadows traveling down the folds of sand.  Had I shot this without any EC the sand would have been brighter and the shadows only faint.  With the sun near the horizon already I shot this image at -.5 EC.      Bracketing means to take a series of images at different exposures in order to ensure one is very close to perfect.  Since you generally never overexpose digital images - the bracketing order for this image would have been to shoot 3 images at 0 EC, -.5 EC, and -1 EC, and that is exactly what I did here.

     From May 1st through November 1st the Zion Canyon spur road is closed to vehicular traffic and you have to park your car and take a shuttle bus.  While this is the peak of tourist season, it is also the least photogenic time of the year so I have never had to deal with the buses - a major inconvenience to photographers.  A couple of miles into Zion the road splits off and the Zion Canyon spur road begins.  It travels north about ten miles passing through Zion Canyon and many of the famous overlooks in the park - such as the Great White Throne and Angel's Landing.

     If you continue past the spur road the highway climbs in a series of switchbacks to the first tunnel, which is about 1.2 miles long.  Coming out of the tunnel you enter an area that is literally packed with spots to photograph.  Layered sandstone, hoodoos, and mesas cover this rock landscape.  A couple of miles past the long tunnel is the short tunnel, just a a hundred yards long.  Past that tunnel the road heads towards the east gate of the park, past Checkerboard Mesa.  While I've seen sheep in other areas - going east past the small tunnel has been the area I've photographed them the most in.   They blend into the lighter rock here and its best to pull over and glass the surrounding mountainsides for them.  In November the rut begins and the desert bighorn are more active and easily seen.

     Side canyons split off every couple of hundred yards and are enticing to hike.  Rock pools, shady glens, and occasional Indian petroglyphs make these short hikes worth the effort.  Bird life abounds in these side canyons, as do lizards and frogs (around the pools).  Mule deer are common throughout Zion but the peak for them is definitely in November when the rut has begun and many deer have entered the park for that.  Zion Canyon from the Lodge to the end of the road at the parking lot for the Narrows hike is best for mule deer.  During the rut muley bucks are very active and there have been times I've seen upwards of a dozen on this single stretch of road.

     My first step is just to open it, or in my case, drag and drop this file into Photoshop (CS 4).  The Camera Raw 5.3 - Nikon D2X dialog box immediately opens showing the image and the control panel for processing the RAW file.  One of the updates to photoshop allowed me to add the Nikon D2X camera information so that when files open, they open with the specifics for this camera.  Now, with the Camera Raw 5.3 dialog box open, lets examine the controls that are available.

     The controls below those - Clarity, Vibrance, and Saturation effect the "color" of the image and how that color is applied.

     When you have a group of images that are similar (thus, the processing will be similar) you can click on that small down/right arrow next to "Basic" and select "Previous Conversion" choice.  You can also select "Camera Raw Defaults".  I usually open my images with the image settings supplied by the camera.

     Experiment with them some, watch what parts of the image they change and how they change.  I don't use these settings a great deal but they have valuable benefits.  While the previous "Basic" controls effect the whole image - these controls only effect parts of the image as determined by their brightness.

     The easiest way to check your results is to zoom in on a section of the image to at least 100% - then apply a level or sharpening or noise reduction - and see how it effects the image.

    The slider controls for these tools make small adjustments to the image easy.  These are global adjustments that effect the entire image.

     Every possible adjustment doesn't need to be made by these tool palettes - once the image is open in Photoshop further processing can be done easily and with just as much control, and at times more control.

PROCESS IMAGE IN CAMERA RAW

     The other tabs open more specialized sets of processing controls and I generally don't use a great deal.  So considering the three sets of controls I've detailed here - these are the settings for this particular image that I choose.  Remember that the processing of an image is unique to you and your eye - and there is no good or bad - just your preferences and tastes in how you want the image to look.  For me, I usually try and make it exactly as I remember it being.

OPEN IMAGE IN PHOTOSHOP

     Now, with those processing changes made, I open the image in Photoshop by clicking on the "Open Image" button below the tool palettes.  When the images open you will see that the RAW file format is still showing with the image file name - for this image it says _1SC6451.NEF.  However, when I try to "save" the image - the Save As dialog box appears and the file format is Photoshop's PSD format.  Other common choices are GIF, JPG, and TIF.  You can NOT resave the NEF file.  What this means is you can go back and reprocess the RAW file at different times in different ways.

     Now, if the JPG format doesn't show in the "Save As" dialog box it means that the NEF format is still in 16 bit mode - so you need to change it to 8 bit mode by selecting  IMAGE>MODE>8 Bits/channel.   A 16 bit RAW file has 65,536 levels of brightness while a JPG file has 256 levels of brightness. 
 

PROCESS IN PHOTOSHOP

     Now, with the image open create a second layer (CTRL-J), then a third layer (CTRL-J).  After making selective changes to the third layer that I like I will collapse it to the second layer (CTRL-E), create another third layer (CTRL-J) and make more changes.  If I like them I collapse it down to the second layer (CTRL-E) and continue until the image is processed as correctly as I can make it.

     Remember that I don't make global changes at this time, I'm making changes to only certain parts of the image - then using masks to paint in those changes only in the selected areas.

     For example, in this image I want to saturate the grape leaves more.  Working on the third layer I pulled up the Hue/Saturation dialog box (CTRL-U) and applied about 16% more saturation.  Holding the ALT key down, I clicked the Layer Mask icon in the Layers Palette and a black mask appears next to the image on the third layer - hiding the layer.  I selected a white paintbrush, big brush and at about 30% opacity on the brush I painted in the higher saturation on the leaves only.  While invisible - the white paint "reveals" that area of the "concealed" layer - hidden by the black mask.   When I finished and reviewed it - and liked it - I collapsed the third layer to the second layer (CTRL-E) then created a new third layer (CTRL-J) - and worked on a different area.

     In this image I tweaked the following areas of the image:  Grape Leaves (color), wood post (brightness/contrast/sharpness), numbers on the post (light levels/contrast), and the grapes (color/sharpness/noise reduction/contrast).  What I finished with is my representation of what I say the other day in the vineyard.  Its an 11mb jpg file.