I have an old photograph from maybe 1880 or so of my great grandfather. It is a full length portrait. After the photo was taken someone had an enlargement made of his head and shoulders (also very old). It is possible to see in this enlargement that there was a LOT of retouching work done either on the negative or on the original print. I think one of the reasons was that with an emulsion of 'ordinary' sensitivity and probably not much latitude, things tenses to get lost in the shadows or highlights. The exposure seems to have been optimised for his face. He was wearing a shirt and tie that, regardless of what colours they were, seem to have come out as very similar shades of very pale grey. Consequently, there has been pencil work to try and make his tie stand out. Also - his coat is very dark, as is the background. There is a bit more pencil work to stop him disappearing into the shadows. It isn't so noticeable in the original print - but looks quite crude in the enlargement.