|SensorKlear II with articulating head and cap|
Lenspen is a Vancouver based company has been making camera cleaning products since 1992 with a proprietary carbon compound that works essentially like a soft cloth-like version of activated charcoal. The material is soft and porous, giving it a tremendous amount of surface area to soak up dust and oil. The company has since branched out from their original lens cleaning product into other areas like screen cleaning and sensor cleaning. A common theme in all of their products is that the cleaning devices are small and self contained, making them easy to pack with your gear. Ostensibly, others have noted these virtues and Lenspen themselves seem quick to cast doubts on competitors.
In use, cleaning is very simple. First use a blower to knock away loose dust, and then use the Sensorklear II to brush away the stubborn particles that won't dislodge with the blower. The hard part is seeing the remaining dust particles. You may need to use a loupe or flash light to see the dust particles, but an easy way is to work under a bright light source and to angle the sensor up until the dust stands out from the light being reflected on the sensor. The articulating tip and indented thumb rest makes holding the device comfortable.
The directions don't give any specific directions on how to brush away the dust; the technique. that seems to work best seems to be a deliberate wiping motion. That is to say, place the Sensorklear head on the glass and with light pressure but deliberate contact, use a small wiping motion so that the carbon material has a chance to pick up the dust. The tool is best for spot cleanings, but you could wipe down the whole sensor if you really had to. The key is to not be timid; some dust can be stubborn (static charge) and will require more than just one pass. A light brushing stroke does not work; what seems to be effective is a continuous motion with the cleaning pad in continuous contact with the glass. As you are moving the pad across the protective cover of the sensor, you should feel a modest amount of drag, reminiscent of the "squeaky" feeling you would get from rubbing your thumb on a freshly cleaned dinner plate. If you come across an oil spot, you must wipe until the oil is completely soaked into the pad or else you will leave a smear on the sensor.
The cleaning pad itself is not meant to leave any residue.... in theory. However, a common complaint of the most dissatisfied users is that the product can leave residual particles on the sensor. The instructions on the package do include a final pass with a blower to remove any residual dust. When you are done you recap the head of the cleaning device and give the cap a couple of twists to refresh the cleaning pad.
Overall, this is an easy to use device that is good for spot cleaning. Though the Lenspen carbon material is meant to soak up oil as well as dust, it is best to use for spot situations. In the hierarchy of cleaning, the Sensorkelar II falls in between the dust blower and a full wet clean. It isn't as final as using the wet method, but it is cost effective and relatively safe; the retail price is $20 USD or less and the product is touted to last 100 cleanings.