What is the White Balance Lens Cap?
The white balance lens cap is a great tool for easily setting manual white balance on the fly and in sometimes difficult light settings. It is also an easy tool to help you transition away from automatic white balance settings, which often are not quite right for the scenes you shoot. Getting the white balance set just right is what the white balance lens cap is made for and it is a very useful tool to have in your camera bag. This tool is available for about $7 to about $60, depending on which type you get, how big it is, and how sophisticated it is.
One of the leaders in this category is the baLens by BRNO, pictured at right. It is more expensive than some but also more sophisticated in its manufacture.
How to Use it
The way it works is simple. You put the white balance lens cap on the front of your lens, then set your camera to custom white balance. Next, get ready to take the shot that will be the basis for the white balance. Every camera is different, so consult your manual for fine points on how to do this. Aim the camera at the light source you are using and press the shutter release button. Because the white balance lens cap has an opaque, translucent white piece of plastic embedded in it, the camera will not be able to focus on anything and you will have to set it to manual focus for this procedure. After your white balance is set, you can switch it back to autofocus.
The white balance lens cap is certainly easy to use, being essentially a fancy lens cap. Any complicated part comes from the ease of setting white balance manually on various cameras.
Some reviews suggest using this product instead of a regular lens cap, just for convenience. I would not recommend that due to the possibility of scratching it. I use lens caps as cheap protection for my lenses. In fact, lens caps I have bought have ended up spending the rest of eternity in such wonderful places as the Norwegian fjords, London Underground, and a Bangkok khlong. Beautiful, for sure, but certainly not where I want my important photography equipment to end up.
One problem with the white balance lens cap is that they are obviously fitted for specific sizes. My lenses have different size rings on the front. Should I really buy three of these devices for the three primary lenses I use? One way around this is to buy a large size white balance lens cap and a series of step-down rings to adapt it to your smaller lenses. Another work-around is to use the one lens you bought the lens cap for to set the white balance, then switch lenses to the one you want to shoot with.
Overall (4 out of 5)
All in all, the white balance lens cap is a good tool to have in your camera bag. What I used to do was carry a few sheets of white paper in my camera bag to use as a reflective white balance tool. The white balance lens cap is head and shoulders above that in ease of use and effectiveness and is much smaller and easier to tote around than the PhotoVision Digital Calibration Target. This would be a good tool to have in your camera bag. The hard part will be deciding which model to buy - an expensive or cheap one. All things being equal, a happy compromise might be to find one somewhere between the extremes.
Photo provided by BRNO.