Converting an image to black & white

There are several ways to convert an image into black and white, depending on how much control of the finished image you want. Some methods work better for different photographs.

Method 1 - Grayscale Document

Open a new page on photoshop – file>new

Choose the Colour mode to be Grayscale.

Open the image you want to convert, and drag onto this blank document.

This is not a great method to use as you first have to figure out the size of your image. You also have no control over the depth of your image.


Method 2 - Grayscale

One of the easiest ways to convert your image to black & white is to use 'Grayscale'. To do this, go to image>mode>grayscale. This, however, does not give you any control over the final image.


Method 3 - Desaturation

The simplest way to convert your image to black and white is to desaturate. To do this, go to Image>adjustments> desaturate (or shortcut shift + ctrl + U). This method does not allow any control over the final outcome.

However, you can change the contrast of the image using the levels. Image>adjustments>levels

Method 4 - 'Black & White'

This method allows full control over the different tones within your image. Go to Image>adjustments>black and white 

Method 5  - Photo Filter

By using a photo filter, you can convert your image to black and white. Go to image>adjustments>photo filter

Using black as the filter colour enables your image to become grey scale. 

Method 6 - Gradient Map

A gradient map is a simple way of making your image black and white. Once again, you do not have much control over the tonal variations.

Go to image>adjustments>gradient map 

Changing the gradient to black>white, gives a greyscale image. 

Method 7 - Threshold

Image>adjustments>threshold

This method gives a cartoon feel image, with bold black lines against a white background. This does not work for all images.

Photoshop Basics

Resizing an image

To resize an image, go to Edit>free transform (or use short cut Ctrl + T). When resizing images/objects, be sure to hold down shift at the same time – this will keep your image to scale. Also, make sure you let go of the mouse before you let go of shift. When you have finished resizing your image, hit enter.

Rotating an image

To rotate an image, go to Image>image rotation. This will give you many options for rotation.

Alternatively, after using ctrl + T to resize your image, if you hover over one of the corners until a curved arrow appears, you can click and rotate freely.


Cropping an image

To crop an image, simply use the rectangular marquee tool to select the bit you want to crop, then go to Image>crop.


Undoing/stepping back
To undo a move, go to edit>undo (or use shortcut ctrl + Z). However, this only takes one step back. 
If you need to undo more than one step, go to edit>step backwards (or use shortcut ctrl + alt + z).


Merging layers
To merge layers (combining several layers into a single layer), go to layer>merge visible, or use shortcut shift + ctrl + E. 
NOTE: make sure you hide any layers that you do not want to be merged.
NOTE: do not merge layers unless you are sure you have finished with them - once merged you cannot go back