Saturday, September 6, 2008

Review: VisibleDust™

By Joan Sullivan

Joan has spent the majority of the past 20 years living/working in and otherwise roaming around Africa and Asia. When she is not designing HIV prevention and behavior change interventions, she is behind a camera. Digital photography lends itself well to such a mobile lifestyle; it is now her preferred medium.

In the War On Dust, we are all reluctant conscripts. Sooner or later, no matter what digital format we’re shooting, no matter how meticulous we are when changing lens, no matter how good our Photoshop skills, we will be forced to choose a weapon and do the unthinkable — clean the sensor.

The good news is that ‘sensor cleaning’ is a misnomer. The hermetically sealed image sensor lies protected behind a low pass filter, so we — and the ubiquitous dust — do not have easy access to it, for good reason. Instead, what we touch during the sensor cleaning process is the low pass filter, not the actual CCD or CMOS.

The bad news is that this silica filter is highly sensitive and can be easily scratched if proper cleaning techniques are not meticulously observed. You could also cause serious damage should the battery suddenly die during cleaning, causing the mirror lock-up mechanism and shutter to release while you are inside the camera chamber. The same risk applies if, for some reason, you use bulb setting while cleaning. Thus, be forewarned [Praemonitus praemunitus]: to minimize risk while cleaning the sensor and/or camera chamber, always place your camera in ‘sensor cleaning’ mode while your camera is hooked up to AC power. If this is not possible, then only a fully-charged battery should be considered as a last resort.

So which cleaning weapon to use?

There is a small but growing arsenal of sensor cleaning methods. These fall primarily into two camps: “wet” and “dry”. Other high tech strategies, such as the new self-cleaning sensor units from Canon and Nikon and built-in dust removal software to delete residual dust spots from processed images, will not be discussed here.

For this review, we tested three VisibleDust products that were received unsolicited from the Canadian manufacturer. These include the VisibleDust DHAP Sensor Cleaning Swab™ (for wet cleaning), the VisibleDust Arctic Butterfly® 724 Sensor Brush (for dry cleaning), and the VisibleDust Sensor Loupe™. All products were tested on an old Canon 20D with plenty of accumulated dust.

Before discussing the wet and dry methods, we’d like to say right up front that we were very impressed with VisibleDust’s sensor loupe. Although there are other less expensive tools to examine camera interiors, we found that the array of six LEDs inserted into the circular interior wall of this loupe provide superb lighting which evenly fills the chamber to improve detection of dust and other debris on the sensor filter as well as within the chamber.

In our opinion, the most important use of this kind of sensor loupe is to help the photographer determine, a priori, what cleaning method is most appropriate for each cleaning session in order to minimize physical contact with the sensor filter. If you see through the sensor loupe that most of the dust is only loosely attached to the sensor filter, then you should start with a dry method such as blowing air (not compressed air!) or the VisibleDust Arctic Butterfly described below, since dry methods are less invasive than wet methods. However, if you see spots on the sensor filter through the sensor loupe, then you will have to use a wet cleaning method which requires physically wiping the sensor filter.

The sensor loupe also comes in handy after cleaning, to examine the sensor before re-attaching the lens or lens cap. In particular, it can help highlight any stubborn particles or spots which prove resistant to your best cleaning efforts.

Using the VisibleDust sensor loupe, we examined the camera chamber of the Canon 20D and determined that most of the dust particles were loosely attached to the sensor filter. VisibleDust’s Arctic Butterfly 724 Sensor Brush is one of several types of dry sensor cleaning products on the market, but it stands out with its patented super-charged fiber technology (SFT). It combines a 16mm sensor brush, a rotating DC motor and two AAA batteries in a plastic housing. By pushing a button on the handle for about 10 seconds -- away from the camera, prior to inserting it into the camera chamber — the head spins rapidly to charge the bristles. These positively charged bristles attract dust, and when drawn gently a few times across the sensor filter, they literally lift dust right off the sensor filter. Pull the Arctic Butterfly out of the camera, spin again to dislodge any dust picked up by the bristles and put the cover back on to protect the bristles. It is very easy to use, and

After using the Arctic Butterfly, we re-examined the sensor filter with the sensor loupe, and concluded that 95% of the dust particles had been successfully removed. However, we could still see one rather large dust particle on the filter.

To remove it, we next used VisibleDust’s DHAP Sensor Cleaning Swab with three drops of VDUST PLUS Liquid as per instructions. After one swipe with the orange cleaning swab, we re-examined the filter with the sensor loupe and saw a perfectly clean filter. What a beautiful sight!

Could we have arrived at the same result using just the wet swab without having first used the Arctic Butterfly? Perhaps, but there is something infinitely logical to trying to remove as much dust and debris as possible prior before physically dragging a swab over the sensor filter. For this reason alone, we would still recommend that your sensor cleaning strategy begin with a quick swipe of the Arctic Butterfly, followed by a quick swipe of a moist swab. However, if you are in a particular hurry and can’t do both, then you will probably get similar results from just the wet cleaning method, which we have been using successfully for several years.

Whatever your sensor cleaning strategy, don’t forget to clean the lens mount and rear element before re-attaching the lens to the body. Furthermore, since the mirror stirs up a lot of dust inside the camera chamber every time you take a picture, it makes good sense to keeping the walls of your chamber as clean as possible as well, especially if working in a particularly dusty environment and if you change lenses frequently. And, on a final note, we have heard from several photographers that storing cameras face down in camera bags with lenses attached also can minimize dust from entering the chamber.

In conclusion, we believe that no one cleaning method will work for all photographers with all cameras in all situations. The rule of thumb is not to be obsessive about keeping your sensor clean, and not to clean the sensor any more frequently than absolutely necessary.

You can see Joan's work at

MAGNAchrom: End of Article

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