Friday, March 14, 2008

Photography tips: white backgrounds

Product photographers often photograph their objects against a white background. This makes the product stand out more and it allows a graphic designer to make isolations for use in other pictures. Photographing against a white background is done in four easy steps.

Use white
I know it sounds silly, but believe me, some people use off-white backgrounds to photograph an object “on white”. It is not impossible, but using an actual white background makes it much easier to have your object stand out from the background. I prefer paper backgrounds, but textiles or plastics work as well.

The light meter in your camera will notice a large white surface and think that the picture is very bright. Left to itself, your camera will underexpose the picture with the white background. So you need to tell your camera to compensate exposure, probably between one and two stops. Determine the exact amount of compensation by trial-and-error, without overexposing your actual subject.

Soft lighting
Using direct lighting is probably one of the most common mistakes made by photographers. Direct lighting causes reflections and harsh shadows. We don’t want those in general and we certainly don’t want those when shooting an object on white. So you need soft lighting. Diffusing and/or bouncing the light create soft lighting. Professional product photographers use light tents or light boxes for diffusing the lights. Light tents are simple frames, covered with a thin layer of white material that diffuses light. The light inside a light tent is softer and bounces around the inside of the tent, helping to reduce shadows. Below are two links to build one yourself. I have built a similar one and it works just fine, as you can see from the pics in this blog.

Post process
The final step is done behind your computer. You should not rely on post processing alone. Of course, if you are very patient, you can isolate any object in Photoshop, but that’s not our purpose here. We are merely fine-tuning the white of the background. As light falls of with distance, your corners may have gone grey. You can use a gradient mask on a levels or curves-layer in Photoshop to correct for grey corners in a natural looking way without overexposing your actual subject.

I did not mention what type of lights to use, did I? That’s because it is not important. You may use sunlight, daylight bulbs, flash light or even a simple bulb. As long as you stick to the above and correct for white balance deviations, you’ll do fine.

More resources:
Build a do it yourself light box
Different way to build a light box
Tutorial for post processing
Tutorial on how to use isolated items in a picture

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