Viewing Image Information

The status bar

The little status bar at the bottom of Photoshop's window is a mine of useful information, if you know your way around it.

Zooming around

The "Zoom factor" box shows the zoom level on the current document. If you want to zoom in or out by an exact amount, double-click in this box, enter the percentage amount, and press Return.

How big is an image in bytes?

The left hand image sizes figure shows the flattened size of the image; this is how many bytes the image will take up when printed. The right-hand figure shows the un-flattened size of the image, or the total space taken up by all the layers of the image. This is approximately the size your file will be when saved as a .psd. If you have lots of layers in your image, the right-hand figure will be a lot larger than the left!

Finding the image width & height

Need to find out the width and height of an image quickly? Open it in Photoshop then ALT+click (Option+click) on the image size figures in the status bar. A little pop-up window will show you the pixel dimensions, as well as the number of channels in the image and the print resolution. This is very handy for entering that "width=" and "height=" information in Web page image tags.

Other statistics

Click on the pop-up menu arrow. Here you see 4 options - "Document Sizes" (the current option), "Scratch Sizes", "Efficiency" and "Timing".

Scratch Sizes shows you the amount of memory Photoshop is using for storing all the open images and the clipboard (the figure on the left). If this number is greater than the number on the right (total RAM available to Photoshop), the program will start to use its scratch disk and you will notice a marked drop in performance.

Efficiency shows you how much Photoshop is using the scratch disk. Ideally this value is 100% (i.e. all work is being done in memory). If this figure drops very low, get more RAM...!

Timing shows how long Photoshop took to do the last task. This will depend on the speed of your processor and disk, and amount of RAM, amongst other things.

10 useful tips for beginners

1. Moving layers with the Control key

You don't need to activate the Move tool to move layers around. Simply hold down the Control key (for Windows users) or the Command key (Mac users) and click and drag on your layer with the mouse:

2. Hiding the Palettes with the Tab key

Are the palettes getting in the way? You can hide them temporarily just by hitting the Tab key. To bring them back, press the Tab key again.

3. Selecting all pixels on a layer

To select all the opaque pixels on a layer (as opposed to using "Select All", which selects the whole layer), hold down the Control key (Windows) or Command key (Mac), and click on the layer in the Layers Palette:

4. Double-click to open documents

To open a document in Photoshop, you don't need to reach for the File > Open menu option or even press Control+O - you can just double-click on the grey Photoshop window background!

5. Dragging layers between documents

You can copy a layer from one document to another by clicking on it in the Layers palette and dragging it across to the second document window:

6. Use Layer Sets

If you're using Photoshop 6 or higher, check out Layer Sets. These let you organize your layers into folders - very useful if you have lots of layers in a document! To create a new Layer Set, click on the folder icon at the bottom of the Layers palette, then drag layers on top of a layer set to add them to the set:

7. Full screen mode

If you're working on a large image such as a photo, you can maximize the available editing area by pressing the F key to toggle between a full screen mode with and without menu bar, and normal editing mode. If you also use tip number 2 above, and the tool shortcut keys, you can do a lot of your work without a menu or palette in sight!

8. Nudging

You can get precise control over the position of your layers by using the arrow keys on the keyboard to nudge the layer around. Hold down the Control key (Windows) or the Command key (Mac) and use the up, down, left and right arrows to move the layer 1 pixel at a time. To move the layer by 10 pixels at a time, hold down the Shift key as well.

9. Choosing colours quickly

Press I to bring up the Eyedropper tool, then click on a colour in your image to make that colour the foreground colour. Press the ALT key and click to make the colour the background colour instead.

You can also press the D key to reset the foreground and background colours to the default (black and white), and the X key to swap the foreground and background colours.

10. Keeping to straight lines

You can often constrain movement of the mouse to the nearest 45-degree or 90-degree angle by holding down the Shift key while you click and drag with the mouse. This works on tools such as the Paintbrush Tool, Line Tool and Move Tool. Great for drawing straight lines!