Okay, this is weird. I was processing another of my recent South Devon Railway images and I realised that the front of the locomotive is not as sharp as I would have expected. The image was shot on 5x7 film using a 210mm Apo-Symmar lens at 1/250th sec at f11 on HP5+ film, now I would have expected a sharper image than that recorded, but when I started working on the image in Photoshop CS5 I noticed that the number on the front of the engine was a distinct double image, but nowhere else showed a similar double image, this is not a blurred image such as would normally be expected from too slow a shutter speed. The film was processed in Pyrocat HD for 8 ins at 24 degrees C with a TF-3 alkaline fix. The image was scanned on my Epson V750 scanner with the better scanning film holder. I have checked the negative on a lightbox with an 8x lupe and it is definitely a double image on the negative! Full Image: focus was on the sleeper 8 up from the trackside marker as can be seen in the third image: SDR: 3205 GWR Collett 0-6-0 5x7 by Ed Bray, on Flickr Second image, the locomotive's number at 100% crop Third image: Focus point on 8th sleeper from tackside marker, sleeper marked 631.