How long was that bloke leaning against that post? Back at that time the exposure was in minutes, depending upon the light.
The photo is a well known one. It is/was in the John Whybrow collection. The date is sometime between 1853 and 1858. We know this because that is the period Thomas Dayson was the licensee and his name is over the entrance to the pub which is on the right edge of the photo. A clearer version of the photo can be found in John Whybrow's book (1)
At this time the collodian process was used by photographers. Apparently In good light this required the sitter to hold their position for just a few seconds (2).
I have seen three other photographs of Birmingham taken around the same time. They are:
a). The then Hyam & Co. store in New Street that was reportedly demolished in August 1857 (3).
b). The visit of Queen Victoria to Birmingham 15 June 1858. See Joseph McKenna's books (4)
c). Holder's Music Hall. Dated as 'pre-1857' in both Joseph McKenna's (4) and Keith Turner's book (5).
(Information from:
(1) John Whybrow's 'How does your Birmingham grow?', 1972;
(2) The Khan Academy website
(3) Jen Dixon's 'Birmingham in the Long Eighteenth Century' website, published 2012.
(4) Joseph McKenna's 'Birmingham as it was: The city 1857-1914', published 1979
(5) Keith Turner's 'Birmingham Pubs' 2008.)