the person who took all the plates might have had a 4x5 cameras, with 400 film holders filled with 2 metal plates each ...
and someone constantly feeding him one holder and another holder and another ... liquid emulsion is about asa 1-1/2
so if the lights were bright and he had a very fast lens
OR if he was kind of crazy, he could have hand coated an extremely long black strip of paper with the same emulsion
and put it in a enormous film holder ( like 100 feet of movie film enormous ) and used something like a noctilux lens
and just had a few large cassettes filled with hand rolled black paper ... ( and an auto winder ! )
unlike wet collodion, you can coat liquid silver emulsion on just about anything, and process it in reversal developer
to make a positive. i've made them on black metal, glass and even photo paper that i put through developer with the lights on to make it black
i've got some black paper to try soon, its coated with emulsion i just have to expose it
800 plates is a ton, its kind of mind boggling.