i used the tester because i have and use a graflex slr ( 4x5 ) camera
and over the years i have re-timed my shutter. i know from how slow
the curtain falls about what speed it is ... i have shot mostly b/w film
and some chrome and c41 film. when i was shooting chrome film it cost a fortune to
process and purchase so i don't want to waste my time ( that is why i had my repair-friend verify my speeds with me )
now ... i am thinking of shooting silver gelatin ambrotypes with this camera since i have a dry plate bag-mag
that has been sleeping on my shelf for around 15 years ... and expose seems to be rather critical with this process
so i verified my speeds again this morning ... if it was plain old dry plates or paper or film, i wouldn't worry about my speeds ..