Colonel Alexander J Greenlaw made calotypes in India in the mid 1850s, and particularly 1855 and 1856. I would appreciate any speculation about what kind of lens he might have used, and where it might have come from. ( And even where I might get a similar one! )

In the early 1850s there was a well-known London supplier of photographic materials named Richard W. Thomas. We know that he supplied Colonel Greenlaw with a camera in 1855. ( I don’t know if he supplied any lenses along with this “tropical” camera. ) Greenlaw’s calotypes were typically 12x15 inches or 16x18 inches and they appear to have a fairly normal field of view. There is no substantial distortion around the edges so the lenses were probably stopped down quite a bit, and the exposures were obviously very long.

Any thoughts or speculation much appreciated!