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   Cleaning a 35mm 'Full Frame' Digital Sensor!

  



 Last Updated  - 17th December 2012



Sensor Dust
Most if not all 35mm 'full frame' digital sensor cameras suffer from some dust on the sensor which is often put there by changing lenses in dusty conditions and/or using zoom lenses that suck dust in due to the inner lens barrel moving in and out! The various camera dust removal systems work very well but every so often a wet clean of the sensor is required. However, it is advisable to FIRST gently blow out any possible hard dirt off the sensor and from inside the chamber, to avoid scratches with any (later) wet clean.


Sensor Oil
Some 35mm 'full frame' digital sensor cameras are manufactured with a liberal helping of oil in the mechanism
whereby as the shutter activates it can spread some of that oil on the sensor. All the blowing in the world only spreads the oil across the sensor so a wet clean of the sensor is the only way to remove it and before it can seep into the sensor whereby it may not be able to be cleaned?

Inspection of Sensor
Many photographers use a long focal length (100mm plus) lens
and shoot an image against a white background at a stopped down aperture of f16 or f22. When they inspect the image at 100% on the computer any dust and/or oil spots can be easily seen in the image. Remember any dust/oil spots that you see at the bottom of the image are actually on the top of the sensor and anything on the right of the image is actually on the left of the sensor (when looking at the sensor down through the camera chamber). I use a Delkin Sensor Scope which also has it's own light to check my sensor before and after any form of cleaning. Dust is usually a neat spot whilst oil tends to have a running edge that is not sharp. Believe it or not hairs actually get into the chamber and on the sensor and they are very obviously seen as hairs under the scope.



Blowing Dust of the Sensor

I use the
Delkin Sensor Scope to check for dust or oil on my camera sensor. In all cases, even if there is oil, I perform a dust clean first -
it is advisable to FIRST gently blow out any possible hard dirt of the sensor and inside the chamber, to avoid scratches with the later wet clean.

I always I use a Rocket Blower to clean out my dust bucket, my 6 year old Canon 5D MK I DSLR camera, which has no dust removal system. IMPORTANT - I always hard blow the Rocket several times away from the camera to heat up the Rocket's rubber bulb and blow out any condensation.

I then hold the camera, sensor facing downwards and I insert the blower's red plastic snout across the chamber from a corner of one of the narrow sides and about halfway to the sensor face but aimed at the opposite corner short edge of the sensor and well away from it's surface then gently squeeze the bulb several times to create a collection of air that sweeps back across the sensor face and down the the sides of the chamber. Surprisingly, I then very rarely have to wet clean the sensor because the dust has been blown out - I also use the Delkin Sensor Scope to check my sensor before and after using the Rocket Blower.

WARNING - A high pressure jet of air and/or wet cleaning can damage your sensor so be gentle and beware that if you damage a sensor it may invalidate any warranty?






Wet Cleaning the Sensor


I use Sensor Swabs Type 3 to wet clean my FF digital sensor, with the camera sensor facing downwards to avoid any overspill of fluid on the swab leaking in behind the sensor. I always mount my camera on a heavy tripod to perform the wet cleaning. 

I always use a clean swab, I remove only the plastic covering, then add 2 drops of fluid on the tip to provide a reasonably wet leading edge on the pad but not dripping.

I start at the left narrow end of the sensor and I use one swab for a (tilt swab right) left to right swipe then (tilt swab left) and right to left swipe - discard swab.

It may take several swabs to clean the sensor, depending on how dirty it is - I also use a Delkin Sensor Scope to check my sensor before and after cleaning.

Swab Cleaning Diagram

 

WARNING - A high pressure jet of air and/or wet cleaning can damage your sensor so be gentle and beware that if you damage a sensor it may invalidate any warranty?
 


NOTE: There are other swab type sizes for smaller sensor cameras. - more information regarding Sensor Swabs

 

 



 

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Richard Lawrence
Scotland
United Kingdom

 

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