I have been using a Wein Pro Sync 2 transmitter and receiver for outdoor flash with fairly reliable results and this encouraged me to add an additional Wein XL8 micro ultra slave for my other light. But when I tried the XL8 it responded very unpredictably to the Sync 2 infrared transmitter (sometimes not going off at all, sometimes going off every 2nd time I fired the transmitter, sometimes going off after my main light that has a Sync 2 receiver, and only working whatsoever when the trigger was pointed straight at the XL8) plus I also noticed there is condensation inside the glass dome of the XL8, even though the weather is mild.
I would have thought that even if the XL8 did not respond to the infrared signal coming from the transmitter it would at least be triggered by the flash going off on the main light about 4 meters away but this was not the case.
The same flash works fine when I hook it up to my camera via a PC sync cable. So I am trying to figure out if I have got a dud XL8 unit or if the problem is the compatibility of the XL8 with the Sync 2 system or... Maybe it is not a good idea to try and use this kind of micro ulltra system outdoors, even though it is designed to do so?