10+ Steps to Better Images in Photoshop Tutorial

Scientific Imaging

3/28/12

10+ steps to better images in Photoshop – tutorial

1. Straighten Horizon

a. Open file 10_1.jpg

b. Use the crop tool. Click outside the crop area to rotate the image so the shoreline aligns with the displayed grid.

c. Adjust the corners (if needed) to include as much of the image as possible without going outside the picture area. Press enter to apply the crop and rotate the image.

2. Master levels with levels adjustment layer

a. Use the same file

b. Go to Layer: New Adjustment Layer: Levels

c. Accept the name for the layer.

d. Hold down the ALT key, and adjust the white slider in the layer dialog window that opens. The image will turn black. As you slide the triangle to the left some pixels will appear in white. Once a few appear, stop. (ignore pixels in blue)

e. Adjust the black slider the same way; again holding down the alt key slide the black triangle to the right. The image will go white; continue to move the slider until you have some black pixels on the screen.

f. Adjust the gray slider by eye to darken or lighten the image. Be sure to have deep saturated colors. This setting can reduce apparent haze in a landscape image.

g. Hint: have the histogram open and set to RGB while making this adjustment.

3. Increase color saturation with a vibrance adjustment layer.

a. Still in the same file go to Layer: New Adjustment Layer: Vibrance

b. Sliding the vibrance control to the right will increase saturation of “pure” colors while leaving neutral tones (skin, gray, whites, etc.) alone

c. Sliding the saturation control to the right will increase saturation of all colors.

d. Sliding the saturation control all the way to the left will render the image in grayscale.

4. Deal with extreme dynamic range (shadows/highlights)

a. Open the file 10_4.jpg

b. Note that while you could lighten the shadows with the levels control, the highlights are blown out.

c. Use the Image: Adjustments: Shadow/Highlights menu item.

d. Adjust both the shadows and the highlights sliders so that the shadows are lightened but keep the highlights from blowing out.

e. Watch for colors going gray when using this control – it is easy to overdo it.

5. Deal with extreme dynamic range (curves)

a. Re- open the file 10_4.jpg

b. Use the Layer: New Adjustment Layer: Curves

c. Click once in the center of the diagonal line in the curves box. This anchors the mid-tones.

d. Light tones are to the right. Click on the diagonal line halfway between the midpoint you just established and the upper right corner. Drag this point down and to the right to form a curve in the line.

e. Likewise, click halfway between the midpoint and the lower left corner. Drag this point up and to the left to brighten the dark areas.

f. You can add additional points and fine-tune the curve. You can also adjust individual colors.

g. Very powerful tool; difficult to master – don’t overdo it!

Deal with extreme dynamic range (dodge and burn)

(adapted from Artie Morris adapted from Tim Grey)

h. Re-open file 10-4.jpg

i. Use Layer:New Layer to open up a dialog.

1. Set the mode to overlay and click the Fill with overlay-neutral color (50% Gray) box. Click OK

j. Select the brush tool and open its properties (the icon of the brush tip 2nds from the left on the properties bar)

1. Set the Brush hardness to 0% and the BRUSH (not the layer) opacity to 10%)

2. Set the brush size appropriately (30-50 in this case)

3. Set the foreground color to white (to lighten)

k. On the new layer, brush with white to lighten dark areas. The effect is subtle; you may have to brush over an area several times.

l. Change to black to darken light areas.

6. Eliminate spots

With spot healing brush:

a. Open file 10_6.jpg

b. Select the spot healing brush

c. Experiment with the size and settings. To begin, try a brush size of 42 pixels and a hardness of 100%; be sure “Content-Aware” is ON.

d. Place the cursor over a spot and click.

e. Generally, you want to work with a brush size somewhat larger than the spot. You can also “nibble” away at a larger spot using a smaller brush and working in from the edges.

f. Avoid leaving a trail of obvious round corrections.

With Patch Tool:

a. Re-open the file 10_6

b. Select the patch tool (under healing brush)

c. Set tool to new selection and source.

d. Left-click and draw around object to be removed.

e. Release cursor and move to middle of highlighted area.

f. Drag to area of similar background and release

g. (Adapted from Artie Morris)

With Clone Stamp Tool

a. Re-open the file 10_6

b. Go to Edit:Preferences:Cursors and under Painting Cursors select Normal Brush Tip, Show Crosshair in Brush Tip and under Other Cursors select Precise. Click OK.

c. Select the clone stamp tool (9th tool down)

d. Right-click to bring up tool dialog. Set diameter to about 10% bigger than spot you are trying to cover and hardness to about 50%.

e. Move the cursor over an area that resembles the area you want to cover. Hold down the Alt button and click.

f. Move the cursor over the spot and click.

g. You can repeat in other areas; you may have to choose a new source area with the alt-click from time to time.

h. You can “paint” large areas with this technique – just be sure to release the cursor periodically so that the stamp “takes” and is available as a source for the next pass.

i. Watch out for visible repeating patterns with this technique.

7. Average Color Blur Technique (adapted from Artie Morris adapted from Robert O’Toole (http://www.robertotoole.com/training/aptats/)

a. Open the file 10_7.jpg

b. Open a copy of this file by using the Image: Duplicate command from the menu. Answer OK to the questions

c. Set up the two images side-by-side (you will need to have all other images closed). Use the Window: Arrange: Tile menu item.

d. Go to the COPY! Use the Filter: Blur: Average menu item to convert the entire image into an “average” pixel. Look at the info panel and note that in this case reds are lacking compared to blues and greens (red is filtered quickly out of water).

e. Now click back on the image side. Set up an adjustment layer by using the Layer: New Adjustment Layer: Curves item. Say OK to the name.

f. In the curves dialog box, click on the middle (gray) eyedropper.

g. Now move over to the copy side that is blurred and click anywhere in the image to pick up the average color.

h. New curves will appear; note that the reds are boosted while the other two colors are minimized slightly.

8. Edge Sharpening (Modified from Tim Grey, Outdoor Photographer, October 2004):

a. Keep the image 10_7.jpg open

b. Select the background layer.

c. Make a copy of the background layer via the Layer: Duplicate Layer command.

d. Make sure the copy is selected.

e. Select entire image - Select: Select All

f. Copy it to the Clipboard - Edit: Copy

g. Create a new Channel - Select: Save Selection (give it a name such as edge)

h. Select the new channel by clicking on it in the channels palette.

i. Paste the copied image onto the new channel – Edit: Paste

j. Find Edges – Filter: Stylize: Find Edges

k. If the image is not satisfactory, adjust exposure with brightness/contrast, levels, or curves – you only want to see in black areas that you want to sharpen.

l. Invert the image – Image: Adjustments: Invert

m. Load the selection – Select: Load Selection

n. Click on RGB tile under channels to return to color

o. View: Extras to turn off selection display

p. Use unsharp mask (or other sharpen filter) to sharpen only the selected area (edges).

q. Now use the eraser on the background copy layer to erase any pixels sharpened in areas where you don’t want sharpening.

9. Highlight a subject with a ring.

a. Open file 10_9.jpg

b. Click on the rectangular marquee tool (one down from the top on the toolbar at the left) and hold for a second or two. Select the Elliptical Marquee from the sub-menu.

c. Make sure the custom toolbar at the top shows a style of fixed ratio at 1:1 height:width.

d. Use the cursor to draw a circle around the specimen in the middle of the image and center the circle around the specimen (the circle can be moved after it is drawn by clicking inside of it and dragging).

e. Use the Select: Modify Border item to bring up a dialog box. Select a width of 8 pixels.

f. Click on the foreground color box on the toolbar at the left of the screen and choose a color for the border.

g. Create a new layer with the Layer: New Layer Command

h. Use the Paintbucket tool to fill the circular ring around the specimen.

i. Remove the selection by using the Select: Deselect item.

j. Double-click on the new layer to bring up the Layer Style Dialog. Experiment with various shadows, strokes, Beveling, etc. to make the ring stand out.

10. Highlight a subject by dimming/blurring the background

a. Use the same file you were just using. Click on the eyeball next to the later with the ring on it to remove it from view.

b. Make a copy of the background layer by right clicking on the layer in the layers box and selecting Duplicate Layer.

c. Use the Elliptical Marquee as described above to draw a circle around the central subject – no border this time.

d. Be sure you are working on the copy layer.

e. Use the Select: Inverse command to select everything BUT the center circle.

f. Hit the delete key – nothing will apparently change. The selected area is deleted, but now you see the background.

g. Click on the background to select it.

h. Use the Select: Deselect command to clear all selections.

i. Experiment with making changes to the background to make the center subject stand out:

1. Try a Gaussian Blur from the Filter: Blur menu

2. Try a radial Blur from the Filter: Blur menu (the zoom blur works best). Note that this setting does not have a preview; you have to apply it. If you don’t like it, undo it.

3. Try simply brightening or darkening the background with the Image: Adjustments: Brightness/Contrast item.

4. If you make a layer from the background you can also use the Opacity command to lighten the background. You might not be able to see how this will look until you save the image as a jpg.

11. More on dynamic Range: Raw Photos

a. Open file 10_11.CR2

b. This will open the camera raw dialog.

c. Above the histogram there are black and white triangles. If they do not have white boxes around them, left-click once on each to activate the white boxes. Areas of overexposure will turn red, underexposure blue.

d. Note that there is significant clipping of whites to the right on the histogram. Slide the Recovery (or highlights) slider to the right to reduce white clipping. Don’t go all the way to the right.

e. Slide the exposure slider to the left to lower the overall exposure a bit. Watch for details in the clouds. It’s OK to leave some red.

f. Adjust the fill light (shadows) slider to the right to reduce underexposure (black clipping, blue areas)

g. Adjust the blacks slider to the right so that there are some pure blacks (blue areas).

h. You may want to slide the brightness to the right as well.

i. Move the clarity slider to the right a bit – this adds some sharpening. If you plan to make a big change in size don’t do too much sharpening here.

j. Move the Vibrance slider to the right.

k. You can move the Saturation slider to the right as well, but watch the color of the clouds and the background.

l. Go back and tweak other settings as needed (adjusting some sliders will affect how others work)

m. Note: If you want to return a slider to the original setting, double-click on the slider triangle.

n. Be sure the image size and resolution (bottom middle) are set to the size you want.

o. Click on Open Image to complete opening the image in Photoshop.

12. Increasing a color: Selective Color

a. Use the file 10_11.CR2 as opened following the steps in #11.

b. Open the Selective Color dialog from the image:adjustments:Selective Color menu

c. Choose neutrals from the colors drop-down

d. Make SMALL adjustments to enhance the color of the lava without adding a color cast to the clouds or background.

e. You can then go to individual colors and make additional adjustments.

13. Enhancing color intensity with layers

a. Open the file 10_11.jpg

b. Make a copy of the background layer

c. Unclick the eyeball on the background

d. Select the background copy layer

e. Use the Select:Color Range dialog and the eyedropper to select the red of the lava

f. Adjust the fuzziness so that the black and white selection display shows most of the lava in white, with little white outside the lava area.

g. Use the Select:Inverse menu item to select everything that isn’t red.

h. Use the delete key to delete everything that isn’t red.

i. On the layers palette, change the drop-down from normal to multiply

j. Adjust brightness of the new layer as needed

k. The new layer can itself be copied in increase the effect.

14. Reducing noise (Morris/Ippolito technique)