There are others
Just to keep the record "straight", the only other F stop timer I know of is the excellent one made by DA ( Darkroom Automation ). The DA F Stop Timer has been discussed here, along with the excellent timer made by RH Designs. Mr. Lindan and Dr. Ross have often contributed to the thread about F stop timers, and in general, have maintained a respectful and much appreciated collegial relationship. There are undoubtedly proponents of each timer, but upon analysis, I suspect ( not owning the RH timer does not allow me to speak with complete confidence ) that the differences between the two products are likely rather superficial in that each is capable of delivering the results promised. One is, forgive the analogy, a "Canon", and the other is a "Nikon".
If there are any other F stop timers, then I am sure the group would like to learn of them. A search of the APUG archives will allow one to learn just about all that one needs to about both of these well made products. More information can be garnered from the respective web sites.
Best of luck with which-ever of the timers one decides to use.
Originally Posted by sim