[Somnium (Aidan)]

so a while back i purchased a camera and filter from an IISer, the filter wheel was loaded with LRGBHa and SII filters but for whatever reason one of the NB filters was not there, the guy was god about it and returned some money for it but now i am in the position where i either have an Ha or SII filter in my filter wheel and i want to buy the other one. i think it is the Ha, but to be honest i have no good reason for thinking that, other than Ha is generally the most used filter and it was in the slot after the visual filters were in, in the standard order. but before i drop some decent money on a filter i already potentially have, is there an easy way to determine which one it is? preferably i would like to do this remotely and not have to drive to the observatory and open up the FW. i am assuming there are some targets out there that have very distinct NB regions.

any thoughts are very much appreciated.