This "mirror trick" can be used effectively in many situations, from photographing a stamp to the side of a barn. Many tripods for example, can be turned into a copy stand by the addition of a cross-arm or by simply reversing the centre column to enable you to photograph pages in books etc.. Despite the convenience, you still have the potential problem of misalignment, in which case this little piece of scrap mirror can be worth its weight in silicon chips.

Please remember these important points:

The mirror MUST be dead flat against the subject; if it's not you may as well not bother using it.

The centre of the mirror should be as close as possible to the centre of the subject.

The camera MUST be a type which allows you to view through the lens.

You must align the camera so the reflection of the camera's lens in the mirror is smack-dab in the centre of your target arrows.

Those using the LCD screen on digital cameras for viewing may find the use of a Grid Screen to be helpful also; you can find out how to make one or simply download a PDF of my template HERE.

Good (straight) shooting.