Sensor Cleaning

[Manfred M]

I see the tech for the blowers is changing. Most originally marketed were developed for lens cleaning.
Now its realised that rubber blowers can age and bits of rubber fall off inside and be blown onto the sensor.
One solution is a silicon rubber bulb. Another are filters on the air in and out of the bulb, though the latter must affect the strength of the blow, but needed if particles are from the bulb itself.

Agreed but we need to remember that most of the "rubber" in the blowers are actually not rubber but some type of elastomer (i.e. a plastic). Any elastomer can deteriorate and silicone is more robust in its ability maintain flexibility and not break down as it ages, so it is definitely a superior material. With those properties, it is also a much more expensive material.

That does not mean other materials in blower bulbs are necessarily inferior, but they should be replaced if there is any visible deterioration of the surface of the bulb itself. The outside surface is more likely to be exposed to UV and chemicals that cause the elastomer to break down, versus the interior that is not exposed to those conditions. If the bulb shows signs of breakdown (a gritty feeling) then it is time to replace it.

Mine is several years old and I have do not see any signs of the material breaking down yet. When I do, there will be a replacement in my camera bag quite quickly.

All that being said, I have yet to see any contaminants introduced into the camera body by my cleaning the sensor with a bulb-type blower. The "dust" has to adhere to the sensor to be a problem and so far as I know there is an adhesive strip below the sensor to capture any random dust and dirt that falls off the sensor. The biggest problem I have found to date is spring, when there is a lot of pollen in the air. Pollen is quite sticky and adheres to anything including the sensor stack.

[loosecanon]

I recently bought a illuminated lens for checking the sensor before and after cleaning. I made a decision not to buy one designed to fit onto the camera mount, instead just hold it over the sensor and move as required.

Checking this out I looked at a sensor on my old 7D which I had a problem with small bits remaining which took several cleans. The sensor was totlly clear, but as I moved the lens about there were minute fibres on other parts of the mirrorbox, especially what looked like a material light trap. Clearly their presence is a concern as at any time they could fall onto the sensor.

I then remembered I had a small suction device originally marketed for sensor cleaning. With this I was able to easily remove the visable fibres so reducing the risk of future problems.

The moral of this seems to be when cleaning also have a look for other issues near the sensor.

[pnodrog]

I do not like the term blower. The understanding that I have is that you should (and its always worked for me) suck/vacuum the dust off as you run the brush over the sensor. I squeeze the blower a few times away from the camera before squeezing and then gently releasing as I brush the sensor. Blowing maybe easier but may just blow the dust to another place inside the cavity behind the FP shutter only to settle back on the sensor sometime in the future. I like to think I have completely removed the dust not just moved it.