How can I tell if there is dirt on my sensor?
There are numerous ways to detect if you have debris on your sensor, but the easiest way is by using the Sensor Loupe® with its 7x magnification and BriteVue XL technology. This will enable you clearly see any contamination on the sensor and within the chamber area itself. If you do not have a Sensor Loupe®, you can still check for debris by taking a test shot and examining it in Photoshop.
How can I tell if the contamination is dust or a stain?
Dust particles will come in many shapes and sizes such as specks and fibers. Stains will usually look fairly round and uniform, and sometimes cast a distinctive halo around the edges. Sometimes it is hard to differentiate between the two so the best course of action is to perform a dry cleaning. Best case scenario: clean, then you are finished. Worst case scenario: a smear is caused, a wet cleaning will need to be performed, followed by another dry cleaning (followed by cleaning your bristles).
How dangerous is it to clean my sensor?
The first thing to understand about cleaning the DSLR sensor is that you are not actually cleaning the sensor but rather you are cleaning the low pass filter that covers the sensor. The filter and sensor are sealed by an O-ring, so the sensor itself is hermetically sealed. The low pass filter is made of silica (glass, quartz) and may have an Indium Tin Oxide coating (for anti-static purposes).
When ever you get a contamination on your sensor, 99 times out of 100 it is going to be a dry dust contamination. These kinds of contaminations are easily removed using the Sensor Brush®/Arctic Butterfly® with their SCF technology and are very safe; The SCF technology lifts the debris from the sensor onto the bristles, unlike other brushes that just sweep the debris, dragging it across your filter with a potential for damage.
On the other hand, depending on the type of camera you have and your vigilance while changing lenses and cleaning, you may get a stain on your sensor. These stains require a different approach that has a higher potential for damaging your low pass filter. In these cases we recommend that you use a swab and liquid combination to remove the stain and follow it up with a dry clean with a Sensor Brush®/Arctic Butterfly®. Unfortunately, because you are dragging the swab across the filter, if there is any debris that has a hardness factor higher than the low pass filter, there is a potential for scratching the glass. Caution should be heeded when dealing with ´welded´ dust, which is a piece of dust that has landed in a water/oil stain and adhered to the sensor when the stain has dried up. The best way to remove these stubborn contaminations is to moisten the debris, let is soak up and loosen up, then try to remove with a swab, followed by a dry cleaning pass.
I have never removed my lens on my DSLR. How can I have dust on my sensor?
Unfortunately, even with great vigilance, it is possible to get a contamination on your sensor. Pre-existing dust inside the camera may have been drawn to the sensor, or, more likely, the friction from the moving parts inside the camera may have generated some dust of their own, which in turn made its way to your sensor.
I have a dust reduction system in my camera, why would I need your products?
While the new anti-static coatings will reduce that accumulation of dust on your sensor, they will not eliminate them all. The shaking action of the filter when it is turned on in some new cameras will shake away the dust, but will only effective remove most (light dust), not all (heavy dust) and will not remove any stains that occur. Also when the dust is shaken off the sensor, it is put into a trough with an adhesive strip. Over time this strip will become saturated and the dust will remain loose inside the camera body. Thirdly, there is software that will remove dust from your pictures, but this is done by interpolation and is not a best practices method as it may unnaturally alter your images.
How often should I clean my sensor?
Only when needed. Examining for debris with the Sensor Loupe® or by taking a test shot can be done as frequently as desired, but cleaning should only be done when necessary to reduce any chance of damage.