Unacceptable sporadic noise at ISO 50

[Joris1]

Using the IQ160 on a PhaseOne body, tethered to CaptureOne, shooting in a studio at 2 sec. exposure, some images were suddenly marred with an incredible noise, resembling tiny little hairs from a colourful woollen sweater.
After switching the back off and back on, and reconnecting the cable, the noise would go away - super clean image at exactly the same settings!

I exchanged the cable for a brand new one - same problem. That seems to eliminate a cable issue.

Not a preview issue - irreparable defect in the files.

It was on a commercial job with client, had to have an assistant check every file as it came in to make sure there was no noise.

Any ideas what might cause this?

[Ulf]

Hi
Your best option is to contact support:
Http://support.phaseone.com
Make sure to include a RAW file.