Thanks for the response Joel. What do you mean by "star sample size"? The way I understand the min star size setting is you want to have it large enough to reject hot pixels but small enough to ensure sufficient stars are included in the HFR calculation. The log says it found 146 stars, I'm wondering i it is using all 146 of them in the HFR calc in which case I could afford to increase the min star size setting. The wording in the log "Calculating HFR with sample size 2" sounds like it is only using two of the 146 stars it found.
Peter