Help! What have I got on my sensor?

[Julian Love]

At some point in the last month I noticed I had some strange blobs showing up on the sensor of my 1Ds Mk II. Despite cleaning both with a sensor brush and sensor swabs / eclipse fluid I have been unable to remove them.

These are not the usual dust spots, but look rather like tiny raindrops. They are small but quite visible when shooting at small apertures. They currently occupy an approximately circular patch covering about 10% of my sensor, just off centre.

I have been shooting digitally for 3 years (original 1Ds and now Mark II) and have never come across this problem before. I never used compressed air in the chamber, or any of the other obvious ways of getting contaminants onto the sensor.

Any ideas on what this might be and how I might get rid of them? It is a real pain as it is forcing me to spend around 10 minutes on each image to clean them before I can send them to my stock agency.

100% crop attached.  [attachment=567:attachment]

Please help!

Julian

[boku]

Looks like a meteorite shower!

I also distress over sensor cleaning issues for my 5D. Hopefully someone will shed some light on this.

[Tim Gray]

If you're using commercial sensor swabs, my experience is that they are too flimsy to get rid of stubborn spots (that resist the visible dust treatment).  Try the "copperhill" method - that works for me on the tough spots...  

http://www.pbase.com/copperhill/ccd_cleaning

I've had to apply moderate pressure a couple of times in the past to get rid of really tough spots.

[mcbroomf]

Those defects look far too similar to each other to be random defects to me.

I'd suggest a trip to Canon, and I'd be very interested in the results.

Mike

[dwdallam]

They look like condensation. I use the rocket blower, peck pads, sensor swipes, and the cleaning solution on my 20D, and I've never had any problems.
http://www.pbase.com/copperhill/image/39082096