Total exposure dose for Falcon 4i DDD camera

Dear colleagues,

Ordinary question -
What is your way of Total exposure dose calculating for Falcon 4i?

Thank you.


ps. also when having the information from EER file

Hi, @Dmitry,

I believe the number you’re looking for is the total dose per square pixel (TotalDose) (e/px) divided by the detector pixel area in angstroms (SensorPixelSize)2 (A2/px). In your case, this would be (34.33 e/px) / (0.93432 A2/px) = 39.33 e/A2. It is likely that the total dose was set to 40 e/A2 during data collection.

If you’re starting a new data collection session via EPU, you can manually set the total dose (e/A2) after optimizing the dose rate to be within acceptable limits.

Hope this helps,



As @joon.lee points out, it can be back-calculated from the header/xml information, but that does not take into account incident loss - just what reached the detector.

Given 34 e-/pixel reached the sensor, it would not be unreasonable to estimate 40 e- total dose was selected, although with thicker ice it could easily have originally been 50 (of the default values, if you didn’t type something manually).

Best to note down what you set in EPU during parameter setup, as we’re interested in both dose-on-sensor and dose-on-sample, and the two aren’t the same thing.