Coffee Filter Custom WB Test

Last updated: 17th December 2004

Technical considerations:

Test shots were taken on a tripod with the following equipment:

• Canon EOS 300D DSLR

• Tamron 28-75 F2.8 XR DI Lens

• Tamron Circular Polariser Filter (Only for shot1, to reduce reflection)

• BonCAFE Bleached Filter bags (1x4 size)

Usage method:

To obtain an image to use as your Custom White Balance, you first need to cover the front element of your lens with the coffee filter.



Your lens should be set to manual focus at infinity (to prevent AF hunting). Next, aim at something white that is illuminated by the ambient light source. If you have a white flash bounce card, it makes an ideal reflector for this purpose.



Make sure your camera exposure settings are correct to avoid under or over exposing the shot. It should look something like this:



After taking the shot, go to your camera's menu and find the "Custom WB" menu. Select the image you just took and set it as your Custom White Balance. Make sure your camera is set to "Custom White Balance" mode (instead of the other WB modes). That's it! Now you can go ahead and shoot with near perfect white balance!

Test setup:

The 'Before' shot in each example was taken using Auto White Balance (AWB). The 'After' shot was taken using the Custom White Balance with all the other settings being kept the same.

No post processing was done other than Unsharpen Mask.

Disclaimer: I realise the shots presented here are underexposed but the whole point is to illustrate the White Balance correction even in low light conditions. I did not want to blow out the highlights caused by the warm lighting.

Shot comparison:

Example 1

	Before Focal length: 28mm Shutter speed: 1 sec Aperture: F/14 ISO 200 Manual focus No flash Auto White Balance
	After Focal length: 28mm Shutter speed: 1 sec Aperture: F/14 ISO 200 Manual focus No flash Custom White Balance

Example 2

	Before Focal length: 75mm Shutter speed: 1/15 sec Aperture: F/14 ISO 200 Manual focus No flash Auto White Balance
	After Focal length: 75mm Shutter speed: 1/15 sec Aperture: F/14 ISO 200 Manual focus No flash Custom White Balance

Example 3

Auto	Daylight
Shade	Cloudy
Tungsten	Fluorescent
Flash	Custom

Conclusion:

Even from this simple test, it is easily apparent that using a bleached coffee filter to set your Custom White Balance greatly improves the white balance obtained. This method is easy to use and extremely cost effective (a box of 40 filters costs about S$2.10!). Furthermore, the results are pretty convincing (short of using professional solutions like grey cards and the extremely expensive Expodisc).

Your mileage might vary depending on your setup and of course, the brand of coffee filter you use. Any comments, questions, flames can be directed to denosha@sgl.per.sg.