I took my Yashica-Mat twin-lens reflex to Chaco about a year ago hoping to do some pictures of the ruins, but the film advance jammed on the first shot. I tried another roll recently on a walk through Albuquerque's Old Town and found that it still has a problem with the shutter release and the film advance. I was able to get past the problem with some jiggling of the focus control, but a good cleaning and adjustment is clearly called for. I found a good service guide on the web, so will try to motivate myself to tackle the job some time in the future. I have several good tlr cameras in addition to the Yashica-Mat, but the Lumaxar lens on the Yashica is a stellar performer.