There are some shots that are unrepeatable. When the sun dips at the last minute there is no opportunity for a re-shoot. With a colour slide the picture would be fit only for the bin. Is it possible to salvage a decent result from a digital image ? This article explains how to get a good result and an example is shown below. This shows a Serco train working into London Bridge - a fairly rare event. The sun has dipped causing the locomotive and half the first coach to be shadowed. The first block of flats on the left is shadowed. The rest of the picture is fine.