Effective Digital Imaging using Basic Composition and Adobe Photoshop Paul S. Marley Instructional Technology Specialist Department of Art Wake Forest.

Effective Digital Imaging using

Basic Composition and

Adobe Photoshop

Paul S. MarleyInstructional Technology Specialist Department of Art Wake Forest University 336.758.4803 [email protected] http://www.wfu.edu/~marleyps/

Basic Composition

• The Rule of Thirds• http://www.ruleofthirds.com (David Freidman)• Photo Tips by Kodak

http://www.kodak.com/eknec/PageQuerier.jhtml?pq-path=2/3/38/315/332&pq-locale=en_US

>>Left to Right>>

Our eyes are trained to move from left to right so the flow of your image should “move” in this direction to make viewing your subject feel natural.

Images can be VERTICAL

If an image isn’t working in the horizontal view try the vertical

Adobe Photoshop

• Curves

• Levels

• Image Size

• Sharpening

Curves (Ctrl + M)

• Curves is used to manipulate the color of an image. Common tasks in Curves are:

1. Balance image’s color

2. Enhance Brightness and Contrast

The Auto (correction) button can be a good place to start on a less than perfect image.

The Info palette should always be referenced while using curves. It shows the R (red), G (green), and B (blue) values for any area in the image.

It will also show you values in the C (cyan)M (magenta), Y (yellow) and K (black) for those same areas. These four values are used by the Offset Printing Industry.

You can see the X and Y coordinates of any desired pixel within the image and get the W (width) and H (height) when using the Measure Tool.

Select Eyedropper Tool (I), set sample size to 3X3 then place the cursor somewhere on the image to read values

Info reference markers can be placed anywhere in the image. Select the Eyedropper Tool, press the Shift key and click the mouse while over the area you want to mark. The values of the area will display at the bottom of the info palette with a marker number. These markers will not print and can be removed by clicking and holding on them while in the Eyedropper Tool and dragging them out of the image area.

Curves allows you to manipulate the colors individually or simultaneously.

The values you are trying to reach are:

Highlight (white) – 240 Shadow (black) – 25

Info marker should be placed in these areas where detail can be seen.

Total white – 255 Total Black – 0

The Curve of the image is set up with the bottom left being the Shadow point, the middle being the Midtone and the top being the Highlight.

To control a point on the curve, click and hold it with the mouse.

Move the Shadow point to the right to increase darkness. Move it up to decrease darkness.

Move the Midtone up and the image lightens down and it darkens.

Move the Highlight to the left to brighten and down to darken.

The image will show the change as it is made.

As you move the Curve you will notice the values are now indicated as:

208/191

The value left of the backslash is the original value while the other is the new value.

After you have made the color correction desired you can Save the changes to be used on other images that may require the same adjustments. Click on the Save button BEFORE you click OK. An .acv file will be generated and you will be prompted to name and file it.

To apply the adjustments to another image, open it go to Curves and click on Load then retrieve the .acv file.

Click OK to finish your manipulation. A Save As at this point would be advisable.

Things to watch:

1. Major corrections may have to be made in multiple moves instead of all at once.

2. Digital photographs don’t hold up well to extreme correction. Artifacting (small random areas of color anomalies) will likely occur, especially when brightening a dark image. Make initial exposures as good as possible.

3. Place a Grayscale in image if possible for more accurate corrections.

You now see the Adjustment Layer in the Layer Palette.

Levels (Ctrl + L)

Levels is another means of color correction that uses a visual interface instead of a graphical. A Histogram of the image’s color spectrum is displayed for reference and manipulation.

Photoshop often gives users multiple ways to achieve the same results. Curves vs Levels is a great example of this point.

Also use the Adjustment Layer for this as you did in Curves

Info reference markers are placed using the same method as described for Curves and serve the same purpose. The same ability to alter individual colors is also present, as is save/load of adjustment files.

Select the color and adjust by moving the slider that represents the part of the spectrum you want to change. Highlight/Midtone/Shadow are indicated by color of the slider.

Images SizeThe first rule of image size is: Know the end result of your image be it print,

multimedia or web. The second rule is always capture as big a file as you can manage easily

(usually 300ppi) because you can always decrease images size. Increasing an images size will NOT improve its quailty.

Image size is determined by W (width) H (height)Resolution (pixels per inch, ppi)

Commonly used resolutions: (in ppi and file type)• Printing = 300 or + (.tif)• Powerpoint = 150 – 72 (.tif or .bmp)• Web = 72 (.jpg)

From the pull-down menu:

Image – Image Size…

If you are changing dimensions then make sure Constrain Proportions is checked to avoid image distortions.

The Link symbol will appear connecting the Width and Height

To change Resolution make sure the Resample Image is checked. If it is not and you alter the ppi the Width and Height dimensions will change proportionally to the change in ppi, leaving your image “size” unchanged.

FYISide dimensions for use by Biomeds Film recorder:

4096 X 2730 pixels

Save as .jpg w/10 compression

send file by Upload page: http://www.wfubmc.edu/biomed/pc_upload.html

then fill out order form: http://www.wfubmc.edu/biomed/order/slides.html (will need budget code or credit card number)

One or two day returnabout $5 per slide

Sharpening:

Visit the section on scanning in my WFU website

http://www.wfu.edu/~marleyps/ps_stuff.htm “Scanning a new image “

The End…?