Hi all - I'm trying to use TimeSynchronizer to sync up images from two cameras, but I'm having some problems. In the following lines: message_filters::Subscriber left_sub(nh, "stereo/left/image", 1); message_filters::Subscriber right_sub(nh, "stereo/right/image", 1); TimeSynchronizer sync(left_sub, right_sub, 10); sync.registerCallback(boost::bind(&callback, _1, _2)); in the callback, both left and right appear to be the same image (they both seem to come from the rightmost subscriber given to sync). I've checked stereo/left/image and stereo/right/image with image_view and they are definitely different. Is there something I'm missing here? Code to reproduce is attached. On a related note, is there a way to use TimeSynchronizer with image_transport rather than subscribing to the image directly? Thanks, -Dan