“Baked On” Dust ?

I have recently been asked by a couple of different people about dust being baked onto a sensor (low pass filter) due to long exposures and heat being generated by the sensor. I had never heard this before, so I went to work investigating. I did see where some people are referring to dust that is held on to the sensor by moisture or pollen as being “baked on” and this is the same as what I refer to as “welded dust”.  Thom Hogan coined the term “welded dust” long ago and we have used it ever since.  Neither of these terms are the best to be using as they do imply high heat is used to hold this dust on, but that isn’t the case.

I tested the heat generated on the surface of a sensor’s low pass filter during a 60 second exposures. Using an Infrared Thermometer to monitor the temperature, all 4 Cameras (Canon 20D, 5D, 5D Mk II and 1D Mk II) had no significant temperature change from room temperature. Sure this is only 4 different cameras and from only one manufacturer, so it truly is totally conclusive but I do venture to say that dust isn’t actually being “Baked” onto the low pass filter.

This entry was posted on 17. June 2009 at 08:03 and is filed under Support. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response or trackback from your own site.