The size of the mirror you need mainly depends upon the distances involved and the need for detail in the reflected image. Estimate the distance from the viewer to the mirror and from the mirror to the area or point to be observed. Add the two, and use the chart (pictured left) as an approximate guide. If in doubt, choose the larger size.

Cheap Convex Mirrors
Like everything in the market there are bargains to be had; but if it's cheap - there's usually a very good reason! Whoever you decide to purchase your next convex mirror from, make sure you know what you're actually getting for your dollar. Cheap priced mirrors often have overly deep curvatures creating poor image & definition. If you can't see clearly or the image is too small, there is not much point in buying it in the first place!  Flimsy framing and hardware simply will not withstand the pressures of time.  Then again, some materials maybe recycled or not 1st grade which can lead to premature failure.  These 'bargain' mirrors are usually sold through outlets which deal in 'anything and everything'. Check them out and then compare them with properly built and designed mirrors from Materials Handling P/L. The choice is yours.....