Unit Five : Post Processing
Raw image exported as JPEG. Final edit.An image of the Massachusetts State House in the centre of Boston, taken on a cold January evening during golden hour.
Sean Makin © 2016 | Nikon D610 | 10s | ƒ/11 | ISO 100 Download the raw file here. Sean Makin © 2016 released and licensed under CC BY-NC-SA 4.0 - If you post your version of this image anywhere, please link to this class and credit Sean.Workflow
Most software follows a fairly logical flow of editing, where you work down the editing panel from top to bottom, you should use this as a general guide of the steps to follow.
Raw image imported.
Step 1: The first step of the editing process is all about “correcting” your image file. Lens corrections can be done by default on import in some software or as a separate stop, this removes vignetting, lens distortion and chromatic aberration. Cropping and rotation, it is useful to refine your composition as early as you can in the editing process removing any distracting elements and cropping to your desired aspect ratio. Perspective correction is useful for images that have straight lines, this ensures they’re parallel and straight. Finally, healing or spot removal is useful to remove dust spots, blemishes or undesirable elements from your image.
Step 2: The next step is white balance, adjusting this allows you to change the colour temperature, lower values make your image cooler (more blue) and higher values make your image warmer (more yellow). You can also change the image's tint, from more magenta to more green. Often the auto WB will do a good job for tint and you can adjust the temperature to taste. If you are only editing a JPEG you have significantly less latitude to apply corrections and should only make small adjustments.
Step 3: The next series of basic adjustments is where the bulk of your editing occurs.
Exposure changes the brightness of the image. Highlights change the brightness of the highlights portion of the histogram. Shadows change the brightness of the shadows portion of the histogram. Whites change the brightness of the whites portion of the histogram. Blacks change the brightness of the black portion of the histogram.
Contrast increases or decreases the difference between the lightest and darkest parts of the image. Clarity is similar to contrast but only targets the bright and dark parts of the mid-tones, allowing you to increase or decrease the difference in brightness of these. Texture targets high frequency (i.e. fine detailed) part of image, allowing you to soften it for a portrait or sharpen it for a landscape or a cityscape.
Saturation allows you to increase or decrease the intensity of the color in your image. It influences all colors and should therefore be used sparingly, if at all. Vibrance is generally a better way to make your colors pop, various algorithms are used to determine which colors to target. A fully desaturated image will be black and white while a fully de-vibranced image will not be.
Step 4: Tone Curve is a graphical way of making targeted changes of different brightness values while keeping a natural falloff away from this targeted brightness. The horizontal axis corresponds to a particular histogram value, while the vertical axis corresponds to an adjusted value. A straight, 45˚ line means no adjustment has been applied while picking a point and raising it above the line raises its brightness while lowering a point below the line decreases its brightness. This can be a great way of creating more targeted contrast changes or changes to very specific brightness values e.g. a certain value in the shadows to bring back detail.
Step 5: Color adjustment to make changes to, hue, saturation and luminance (HSL) of e.g. colour, intensity, and lightness/darkness of specific colors across the whole image. This tool allows you to make subtle tonal changes, or strongly color grade your image to taste. Some image editors also have ways to apply specific colours to the highlights, mid-tones and shadows and control the hue and saturation of this color adjustment.
Step 6: Local adjustments are a powerful tool to alter areas of the image selectively. There are normally two ways to select the area in which to apply the adjustment. Brushes allow you to paint areas, you can control brush strength, size and the feather or fade of the edge of the brush. Masks are a larger area tool where you might use a radial mask, a gradient mask or some other shape offered by your software. More comprehensive masking tools can allow you to target specific brightness, colours or textures. Generally, you will have the full suite of basic adjustments as described above available to alter the area to which you selected to apply adjustments.
Step 7: Sharpening and noise reduction are some of the final steps of the editing process. Sharpening lets you bring out finer details in your image, making textures and details in the image pop. You’ll usually have control over the amount of sharpening, the radius of the sharpening as well as being able to mask off certain areas from being sharpened. All images will need some degree of sharpening applied to them.
Noise reduction allows you to reduce the amount of random noise across your image. There are two primary types of noise, colour which is usually the green and red mottle and luminance noise is more like like a texture. Even at ISO 100 there is still a need for a small amount of noise reduction. There are also “AI” denoising tools such as Adobe Lightroom (AI) Denoise, Topaz DeNoise AI, and Luminar Neo, which can do excellent jobs at reducing noise even in very extreme situations. These can be computationally and time intensive, depending on your computer so they are not suited to applying to large numbers of images.
For both of these, be careful how much you apply as you can quickly cross into too much territory, resulting in odd textures and details.
Step 8: Before and after side by side
Step 9: Output (or export) settings are important for getting the image you worked so hard to create and edit into its optimal state for its final purpose.
For a lot of uses, you’ll want to resize your image as some hosts will not accept large images or may just display them poorly so it’s better to resize them yourself. Generally speaking, Instagram likes 1000-pixel long edge, Facebook 2000-3000 pixels and full resolution can be useful for uploading everywhere else.
Output sharpening allows you to add some final sharpening depending on how your image will be displayed, this generally is proportional to the resizing you do to your image above. More advanced users may want to have 100% control over this step in Photoshop or similar.
With more and more cameras having GPS included it is usually good practice to strip the location metadata from images you make public in case there may be sensitive location data attached, e.g. your home etc.
For print, there are more advanced ways of proofing your image to ensure it prints well but that is well beyond the scope of this lesson. The user manual of your particular piece of software is generally the best way to do this, alternatively, your printer may have some suggestions for delivering files to them.