Ways of Seeing

The BBC broadcast John Berger's Ways of Seeing in the 70's, when the world was in black and white.  Despite its age and lack of colour this is still regarded as a very important series to watch.  In it he examines how external influences affect how we view an interpret imagery.  It is a total of four programmes lasting for two hours, you should find time to watch them, but not necessarily in one sitting!

Ways of Seeing - all four programmes.

Aperture

Below is a link to notes on Aperture and Depth of Field.

Aperture

Depth of Field

Levels

Levels

Correcting colour casts and contrast. The destructive Method.

After scanning, or downloading from a camera, the first task should be to correct the contrast. The contrast control is a little crude so Levels or Curves give you much more control.

Use CMD and L to get the levels window. You will see that the histogram shows that there is very little at both the black and the white ends of the graph. Hold the Alt key down and select the white slider, you will see the screen turn black. Now move the slider to the left until the highlight areas start to show through. If any go white, they will appear burnt out on the image. Repeat the process with the black slider, this time the screen goes white. Repeat as necessary until the contrast is acceptable.

Select the centre eye dropper, this is mid grey. You now need to find an area in the image that you wish to appear as a neutral grey. Click on the area and you will see the colour balance change. The program uses the area you have selected as a reference and alters the 

colours to balance this to grey.

Non Destructive

To avoid permanently altering the image use a Levels adjustment layer.

Curves

Curves

Curves are one of the most useful tools in Photoshop, it allows you to fine tune the contrast across a range of tones, in fact you can add up to 14 adjustment points to the graph.  The tool can be used in a variety of ways.  You can either adjust all three colours simultaneously or individually by selecting the appropriate channel from the drop down menu.  This is particularly useful for correcting colour casts.  

It can be used either as a destructive editing tool or in a non-destructive manner.  You should use the non destructive method as a preference.  The destructive method is accessed via Image - Adjustments - Curves.  This is only reversible while the file is open using the History palette.  Once the file has been closed the image is permanently altered - destructively edited.  Nondestructive editing is carried out via the layers window, as an adjustment layer.  From the half white, half black circle at the bottom of the layers window select curves.  You will se that this creates a curves adjustment layer which you can always return to, even after closing and reopening, as long as you do not flatten the image.  The following examples where carried out using this nondestructive method.

A curve graph resembles the characteristic curve graphs that manufacturers supplied for films, but initially the line is a straight diagonal.  The left side represents the dark tones and the right side, the light tones.  By adjusting the line you can control the tones represented in the image.

It is normal to start with the shadows.  For this image the line is pulled down slightly on the left until the dark areas are set.  This is like setting the dark point on levels

Now the top right of the line is lifted until the highlights are as desired.

Additional anchor points can be added along the line to adjust the various tones in between.  If you decide that an added point is wrong, it can be removed by simply dragging it off the side of the graph.

Before

After

Opening in Photoshop

Opening from iPhoto.

I only recommend that you use iPhoto for importing and viewing your work.  To manipulate the images you should open them in Photoshop. 

Open up the file, or library and select the image that you want to edit in Photoshop.   Now might be a good time to rotate any images that are the wrong orientation.  If you are going to be working on several then this can save some time later, when you are ready to open the image in Photoshop, simply click on your chosen image and drag it onto the Photoshop logo.

Drag and drop method.

This is one of the quickest and most used methods.

Open the file that contains the image, or images, that you want to open.  You can open either one or several mages at the same time.  Make your selection and simply drag it onto the Photoshop logo on the dock at the bottom of the screen.  On a PC, or on a Mac not using the dock, use an alias for Photoshop on your desktop and simply drag the image onto this.

File and open.

This is the most reliable method, but the slowest.  This method only opens one image at a time in some older versions.  From Photoshop go to file and then open (or CMD and O).  Choose the folder that contains the image you want to work on from the drop down folder.  Now either double click the file or select it and press open.