When I check my 7 year old compact Trinovids, I notice they need some readjusting. I am not really aware of having banged them anywhere, but horizontal lines are no longer at the same level in the two barrels. However, if I fold these barrels the other way (something that can no longer be done with the Ultravids), the lines are just about right again. There is still a slight difference, but nowhere near what the proper folding shows. In fact, the binoculars can be used comfortably in this way. I now wonder why there is this difference. Is it that the two hinges are not exactly parallel and thus compensate to some degree? And if that is the case, I suspect there must also be some differences in well collimated binoculars depending on how far the barrels are folded out.