There's a happy happenstance - the series number matches the model number. Many years ago now, I bought an EOS 50E, which replaced the EOS 100 and I hoped would work for me. It introduced a so-called retro look - a two-tone silverish and black body, plus a couple of knobs on the body - the main mode dial was similar to the previous model save the locking mechanism, although with the metering mode switch around it, but the focus modes were now on a dial in the traditional home of the shutter speed dial, with the drive modes controlled by a switch surrounding this dial. I never really liked the camera, and when the back lock broke, I replaced it and sold it. And then some years later, I saw a 55 for a decent price, and snapped it up. It was a Japan-only model that later got sold off cheap in Dixons (or maybe Jessops, can't recall). Differences are that it's an all-black (and very much smarter) body, has a databack, and a panorama switch. The panorama mode as usual just masks the negative, but there are 2 lines in the viewfinder to indicate the crop, and 4 orange LED arrows that highlight the crop lines when engaged. And for some reason, I much prefer it to the 55E... Today, I suddenly found a BP-50 battery pack in a drawer, which made me realise that it was the 50/E/55 battery pack, taking 4 AA batteries. So I whacked some in, shoved it on the 55, mounted a lens and took it out for a whirl - there still being a film in it. Balance with the battery pack is pretty good. The eye-controlled focus (with the massive total of 3 focus points) appears still to be calibrated to my eyes, which surprised me - still works well, though I can't get the eye controlled DOF preview to work. Never mind, a custom function allows me to link the exposure lock to DOF preview. Handling is pretty good - it has the usual Canon front and back dials for control of shutter speed, aperture and/or exposure compensation. 11 custom functions allow the camera to be somewhat tailored to the individual - but nothing like to the same extent of the equivalent digital model. And when I think how rude I've been about the 50E over the years, I really like the 55, especially with the battery pack - very unusual for me.