Currently, as far as I can tell from the output plots, the search range for angles and shifts in local refinement represents a hard cap for the overall job (is this correct?). By contrast, local search in other programs such as Relion is reset at each iteration, allowing for slow progression towards a nearby minimum without explicitly capping the amount that angles/shifts can change by.
Would it be possible to add an option whereby changes are capped per iteration, rather than for the job as a whole?
The reason I ask is that in several cases with small masks I have got the best results using a very small search range - e.g. 1 pixel for shifts, 2 degrees for angles. I expect this is because using a larger search range particles get stuck in local minima of some sort at early iterations, where the map is relatively featureless, but it seems like capping the allowed changes may be preventing some particles from finding their optimal orientations.