Cutoff value for high intensities

[svanterwingen]

There seems to be a cutoff value for high intensities at which the viewer just shows one color (e.g. yellow in Viridis color mode). What is that cutoff value and should it really exist? Sometimes it throws me off when focusing the beam.

[erikfrojdh]

When Jungfrau detector is close to saturating Jungfraujoch sets the pixel value to int32max (I think) to indicate that something went wrong.

Maybe there is a way to disable this but it would anyway be a flat top with almost only the same values.

Workaround:

In case there is a strong need for correct pixel values with a focused beam one could:

• Set a very short exposure time ~3-5us
• Take new pedestal
• Focus the beam
• Go back to the normal 480us exposure time
• new pedestal
• Measure

This extends the dynamic range of Jungfrau by a factor of almost 200, but at the cost of duty cycle.