How do I get a pure white background in product photography without overexposing the subject?

Question

I’m photographing a product in a small light box and want the background to appear pure white (#ffffff), but I’m struggling to keep the product properly exposed at the same time. If I expose for the product, the background looks gray; if I push the exposure until the background is white, the product becomes overexposed.

I’ve tried many settings, but my results suggest the subject and background are being affected together rather than independently. What’s the correct way to light and shoot products so the background goes pure white without blowing out the item? Can this be done in a small light box, or do I need a different setup?

user1375 · Accepted Answer

There are many improvements that could be made here. Firstly, you need to use a much longer exposure, and a lower ISO setting. Get a tripod, even a cheap one, and use mirror lockup. Could do with stopping down a bit further for depth of field.

Post processing

You might be able to get away with your current shots, with some post processing. Here I've taken the second shot and used levels to darken the product whilst leaving the background pure white:

Lighting

The proper solution is to look at your lighting. The reason that you cant get the right balance no matter what settings you use is that both the product and background are being lit by the same source, so you can only alter the brightness of both, not each one individually.

Usually you'd have one light for your subject and one for the background. This gives you the correct amount of control for optimum results. However that is only if you have a large curved white background. Compact light tents such as the one you're using wont allow you to light your subject individually.

One solution is to black out any parts of the light tent not visible in the shot. That way the amount of light hitting your subject will be decreased, making it darker, without affecting the brightness of the background (since you wont touch any parts that are in shot). Get some thick black card, cut it to size and tape it inside the light tent.