2555 Day 17 Technical Histogram Review The Levels Eyedroppers Another way to apply a Levels adjustment is to use the eyedroppers on the left side of the histogram in the Properties panel Instead of dragging the sliders below the histogram, you can use the eyedroppers to sample pixels that should be black, white, or neutral gray, and Photoshop adjusts the sliders for you. Before using, grab the eyedropper tool and change the options bar’s Sample Size menu to 3 x 3 Average. This will tell Photoshop to average several pixels around the spot where you click, which is much better for color-correcting. Black eyedropper- resets the image’s black point (shadows) Gray eyedropper- resets the image’s gray point (midtones) White eyedropper- resets the image’s white point (hilights) Curves The most capable luminance command Takes the histogram and scales it to fit inside of a square graph You can map any luminance level to another one

To create a Curves Adjustment layer, choose Layer New Adjustment Layer Curves. The Properties panel pops open to reveal a grid with a diagonal line running from the bottom left to the top right

The diagonal line, which is the actual curve, represents the original brightness values of your image. To adjust these values, you can place up to 14 points along the diagonal line. To add a point to the curve, simply click the diagonal line, or make Photoshop add it by click the Auto botton or activating the Targeted Adjustment tool and then clicking your image. Each point on the line corresponds to a brightness value in the horizontal black-to-white gradient bar below the grid. The direction you drag a point determines whether the brightness of pixels in that tonal range increases or decreases: Drag upward to increase brightness or downward to decrease it. Instead of dragging the adjustment points around, you can nudge them with the up and down arrow keys on your keyboard. It’s easier to make precise adjustments this way, and it keeps you from accidentally changing contrast by draggin the point left or right. The grid behind the curve is merely a visual aid to help you move points around and determine which part of the tonal range you’re affecting.

To change contrast with the curve, you change the angle. If you steepen it, you increase the contrast in the image; if you flatten it, you decrease the contrast. Just select an adjustment point by clicking it and then use the left or right arrow key to nudge it one way or other. JPEG vs. RAW Correcting Images in Camera Raw Camera Raw is a powerful plug-in that lets you correct the color and lighting of images shot in Raw format, as well as JPEGS and TIFFs. The adjustments you make in Camera Raw are nondestructive; instead of applying them to your image, Camera Raw keeps track of them in a list it stores within the image or in a file called Sidecar XMP. White Balance

Changing White Balance in Camera Raw

When you set an image’s white balance, you’re telling camera Raw what color the light in the image should be. Changing the light’s color changes all the colors in the image. In Camera Raw you change white balance by choosing one of the presets in the Basic tab’s White Balance pop-up menu. Or you can set it manually (and maybe more accurately) using Camera Raw’s White Balance tool. Press I to grab the tool and then mouse over to your image and lick an area that should be white or light gray. Keep clicking until the image looks correct, and then adjust the temperature and tint sliders until you get the color you want.

Exposure Fixing Exposure in Camera Raw

The next group of sliders in Camera Raw’s Basic tab lets you adjust an image’s exposure and contrast (the difference between light and dark pixels).

Camera Raw gives you the following sliders:

Exposure. Exposure is determined by how much light your camera’s sensor captures. You can think of this slider as controlling overall image brightness; drag it right to lighten your image or left to darken it. Exposure is measured in f-stops (the number indicating how much light your camera’s lens lets in), and has a range of –5 to +5. Be careful not to drag this slider too far either way or you’ll start to lose details. For that reason, it’s a good idea to turn on Camera Raw’s clipping warnings so you can see if you’re destroying details: Press U (as in Underexposed) to turn on the shadow clipping warning and O (for Overexposed) to turn on the highlight clipping warning.

Contrast. Drag this slider right to increase the image’s contrast (the difference between its light and dark pixels) or left to decrease it. Increasing contrast makes the light pixels lighter and the dark pixels darker. This slider used to be last in the list, but now Adobe recommends adjusting it right after Exposure. Highlights/Shadows. These new sliders control tone mapping, which is the way Camera Raw shifts (remaps) the image’s colors from what was captured by your camera to what can be displayed onscreen or printed. Drag the Highlights slider left to darken an image’s highlights, or right to lighten them. The Shadows slider works the same way: Drag it left to darken shadows, or right to lighten them. To produce natural-looking images, don’t drag either slider past 50 in either direction. To even out the lighting in your image, try setting the Highlights to –25 and the Shadows to +25. Whites/Blacks. These sliders let you recover lost details in overexposed highlights and underexposed shadows, and get rid of clipping warnings. If you drag the White slider slightly to the left, you can make the red clipping warnings

in your image disappear and get some details back in those areas (dragging it to the right overexposes highlights). The Black slider works just the opposite: To lighten your image’s shadows and clear any blue clipping warnings, drag this slider slightly to the right. Both sliders are meant for fine-tuning images, so keep your adjustments to the bare minimum.

Making Colors Pop with Camera Raw

To intensify your image’s colors, give the next three sliders in Camera Raw’s Basic tab a tug:

Clarity. This slider boosts contrast in the midtones, increasing their depth so your image looks clearer. You’d be hard-pressed to find an image that wouldn’t benefit from dragging this slider to about +50.

Vibrance. Use this slider to intensify colors without altering skin tones; less effect on highly saturated (intense) colors and won’t destroy skin tones. If there are people in your image, this is the adjustment to.

Saturation. Intensifies all the colors in an image, including skin tones. So don’t use it on people pictures unless you like fluorescent skin.

Camera Raw’s Adjustment Brush The adjustment brush lets you selectively tweak certain areas of an image by painting them. When you activate the adjustment brush, a host of adjustments appear on the right side of the Camera Raw window. You will see the same adjustments, with these extras:

Sharpness lets you accentuate areas of high contrast in an image to make them look sharper Noise Reductionlets you selectively paint away the colored speckles that appear in images shot in extremely low-light conditions, or at a high ISO (your camera’s light-sensitivity setting). Moiré Reduction is also new in Camera Raw 7 and helps remove the repeating pattern that sometimes appears in scans of printed images (think dots upon dots but not precisely lined up). Color lets you paint a colored tint onto an image.

The sliders below the Color setting control the adjustment brush’s cursor To use the adjustment brush, choose the type of adjustment you want to make using the sliders on the right, mouse over to your image, and then paint to apply the adjustments. Or, paint the area you want to adjust first and then tweak the sliders. Either way, a little greenish pin appears to mark the area you adjusted; press V to show or hide the pin. Behind the scenes, Camera Raw creates a mask that hides the rest of your image so you can continue to tweak the adjustment sliders even after you’ve finished painting. Camera Raw updates the area you painted to reflect those changes.

Graduated Filters The graduated filter tool lets you apply adjustments like a graduated filter that screws onto the end of a camera lens. When you activate this tool by clicking its button at the top of the Camera Raw window you get the same set of adjustments as with the Adjustment Brush (except for Erase mode). With this tool, you apply the changes by draggin a line to apply a gradient rather than painting across the area that needs adjusting with a brush cursor. Creating High Dynamic Range Images

Very few images exploit the full range of brightness values from light to dark. Digital cameras can collect only so much data in a single shot . To capture more info, you can shoot multiple versions of the same shot at different exposure values (called EV) by varying exposure, and the combine them later in Photoshop into what’s known as a high dynamic range (HDR) image. To create an HDR image, start by bracketing your exposure. Bracketing- deliberately over and under exposing a scene. You can do this manually or use exposure compensation in your digital camera. In order to HDR to be affective, you would need to do this with a tripod. In photoshop, choose File Automate Merge to HDR Pro Navigate to where the images live on your hard drive and then click OK. Photoshop combines the images into one document and auto-aligns them on separate layers. When finished, you see the refulting image in the new “Merge to HDR Pro” dialog box In the “Merge to HDR Pro” dialog box, turn on the “remove ghosts” checkbox if the subject of your images moved between shots or has a lot of soft edges. From the Mode pop-up menu near the top of the “Merge to HDR Pro” dialog box, choose a final bit depth for your image. Choosing 32 bit makes Photoshop keep all the dynamic range information captured in the original images. However, 32-bit images contain far more information than your mnitor can display. If you picked 8- or 16-bit in the previous step, choose a conversion method from the pop-up menu to the right of the Mode menu.

Local Adaptation gives you a slew of additional options and even lets you apply a Curves adjustment to your image right there in the “Merge to HDR Pro” dialog box. Choose this option if you’ve mastered Curves and then tweak the settings in the following sections of the dialog box:

Edge Glow behaves much like the Clarity slider in Camera Raw. Use the Radius slider to control the size of the hazy glow you see around soft-edge items where there’s little or no contrast; drag it left to make the edge glow smaller, or right to make it larger. Use the Strength slider to control the glow’s contrast (drag it right to increase contrast, or left to decrease it). Tone and Detail has controls much like those in Camera Raw’s Basic panel with the addition of Gamma, which modifies the overall flatness and brightness of the image.

The Advanced panel lets you tweak the image’s Vibrance and Saturation to alter the intensity of the colors in the image as well as its Shadow and Highlight brightness values. The Curve panel (click its tab to display it) lets you make a Curves adjustment.

Equalize Histogram compresses the dynamic range of your HDR image, while trying to maintain contrast (it gives you a peek at what your blended image looks like). This method doesn’t work quite as well as the others because it doesn’t have as many options, and it tends to make the darkest shadows black.

Exposure and Gamma lets you adjust the image’s exposure to make the highlights brighter or the shadows darker, or both. Drag the Exposure slider right to brighten the highlights, and use the Gamma slider to set the comparative brightness difference (across the series of shots) between shadows and highlights (drag it left to darken the shadows or right to brighten them).

Highlight Compression makes the brightest part of the image white, even if it’s brighter than white in the 32-bit file. Pick this method if you want to see details in your image’s highlights without changing its overall contrast.

Click OK to create the HDR image. Photomerge File Automate Photomerge Tell photoshop whether you want ot use individual files or a whole folder The Photomerge command combines several photographs into one continuous image. For example, you can take five overlapping photographs of a city skyline, and then merge them into a panorama. The Photomerge command can assemble photos that are tiled horizontally as well as vertically. When taking your images: Overlap images sufficiently

Images should overlap by approximately 40%. If the overlap is less, Photomerge may not be able to automatically assemble the panorama. However, keep in mind that the images shouldn’t overlap too much. If images overlap by 70% or more, Photomerge may not be able to blend the images. Try to keep the individual photos at least somewhat distinct from each other.

Use one focal length If you use a zoom lens, don’t change the focal length (zoom in or out) while taking your pictures.

Keep the camera level Although Photomerge can process slight rotations between pictures, a tilt of more than a few degrees can result in errors when the panorama is assembled. Using a tripod with a rotating head helps maintain camera alignment and viewpoint.

Stay in the same position Try not to change your position as you take a series of photographs, so that the pictures are from the same viewpoint. Using the optical viewfinder with the camera held close to the eye helps keep the viewpoint consistent. Or try using a tripod to keep the camera in the same place.

Avoid using distortion lenses Fish-eye and other distortion lenses can interfere with Photomerge.

Choose choose File > Automate > Photomerge Under Source Files in the Photomerge dialog box, choose one of the following from the Use menu:

Files Generates the Photomerge composition using individual files. Folders

Uses all the images stored in a folder to create the Photomerge composition. Select a Layout option:

Auto Photoshop analyzes the source images and applies either a Perspective, Cylindrical, and Spherical layout, depending on which produces a better photomerge.

Perspective Creates a consistent composition by designating one of the source images (by default, the middle image) as the reference image. The other images are then transformed (repositioned, stretched or skewed as necessary) so that overlapping content across layers is matched.

Cylindrical Reduces the “bow-tie” distortion that can occur with the Perspective layout by displaying individual images as on an unfolded cylinder. Overlapping content across files is still matched. The reference image is placed at the center. Best suited for creating wide panoramas.

Spherical Aligns and transforms the images as if they were for mapping the inside of a sphere. If you have taken a set of images that cover 360 degrees, use this for 360 degree panoramas. You might also use Spherical to produce nice panoramic results with other file sets.

Collage Aligns the layers and matches overlapping content and transforms (rotate or scale) any of the source layers.

Reposition Aligns the layers and matches overlapping content, but does not transform

(stretch or s kew) any of the source layers.

Select any of the following options: Blend Images Together

Finds the optimal borders between the images and create seams based on those borders, and to color match the images. With Blend Images Together turned off, a simple rectangular blend is performed. This may be preferable if you intend to retouch the blending masks by hand.

Vignette Removal Removes and performs exposure compensation in images that have darkened edges caused by lens flaws or improper lens shading.

Geometric Distortion Correction Compensates for barrel, pincushion, or fisheye distortion.

Click OK.

Photoshop creates one multi-layer image from the source images, adding layer masks as needed to create optimal blending where the images overlap. You can edit the layer masks or add adjustment layers to further fine tune the different areas of the panorama.