With a drawn sword at the ready, this Royal Artilleryman stuck formidably martial pose for Aldershot photographer R. W. Elliott. His dark blue uniform jacket has dark chest braiding and cap cords as opposed to the usual gold/yellow as worn by the Royal Horse Artillery. The lace band on his forage cap is also dark and would be gold for Bobardiers and above in the Royal Horse Artillery.
This seeming anomaly could be the result of the peculiar color shift that occurs in some 19th Century photographs in which yellow can appear very dark, or even black. It could also mean that the uniform details in question were not gold/yellow at all but a different color such as red/scarlet which usually appears very dark or black in monochrome photographs. If the latter is the case then this soldier may have been a member of a volunteer artillery unit.
The other ranks of the 2nd (Tynemouth) Artillery Volunteers horse battery wore such a jacket. As to this mn being a volunteer is open to question.
R. W. Elliott - Photographer
93 High Street, Aldershot, England