Make a cropping tool

Professional graphic designers and researchers often use a crop tool, known as croppers, to ensure the right part of a picture is displayed when sent to repro and to visualise a crop when placing in a layout. But this handy gadget can also be useful to decide what part of a digital image to crop.

It's just two pieces of card cut into L shapes that are used at 180 degrees to each other forming a window that can be adjusted in size and proportion to make a mask around a photo.

As you slide the Ls closer together the window gets smaller and the crop becomes harsher. When using it on a computer screen it masks off the area that will be cropped, allowing you to play around with the shape and see the result in the middle. When you are happy with the crop you would pick the Crop tool from the image editing program and crop to the same shape.

You may say 'I don't need a card based gadget if I have an electronic one', but you'll soon find that using the card version is quicker and more responsive. The fact the area to be cropped is hidden behind the card mask helps you view the uncropped area with greater accuracy too.

The good thing is you can make one really easily. All you need is two A4 sheets of card (one if you're resourceful.

Mark a straight line parallel to one edge about 50cm in from the edge and do the same on the adjacent edge. Then cut out the L shape. Do the same with the second sheet.

To use them just hold one cropper in one each hand make a frame and place it over the image on computer screen (above left) or photo on lightbox (above right) and then adjust the frames to crop allowing you to see the cropped image in the centre.

Some professional photographers use these before taking a photograph to visualise which prime lens to use, but with zooms it's unnecessary. You'd need a smaller pair so you can carry them in a gadget bag and you would mark the frame with focal lengths you own so that you could quickly adjust the masks. Then when viewing at a certain distance the croppers would show you the view each lens would give.