Archived posting to the Leica Users Group, 2000/09/24
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]I don't have an F stop timer but do use the system with an ordinary timer - which is remarkably easy - when setting the time just think in terms of a progression doubling the time - i.e. 2, 4, 8, 16,32,64 seconds etc If you begin from the test strip stage - expose the whole of the strip for 2 seconds at your chosen aperture, cover a small part of the sheet and give another 2 seconds to the rest of the sheet, cover the original portion plus another bit, give the rest of the sheet 4 seconds, cover a further section of sheet and give the rest an 8 second exposure, cover a bit more and give a 16 second exposure. cover a bit more and give the final section 32 seconds. when processed the test strip will show bands for: 2 seconds 2+2 seconds = 4 seconds = 1 stop extra 2+2+4 seconds = 8 seconds = 2 stops extra 2+2+4+8 seconds =16 seconds = 3 stops extra 2+2+4+8+16 = 32 seconds = 4 stops extra 2+2+4+8+16+32 = 64 seconds = 5 stops extra I find this system much simpler when estimating an exposure between two steps, as the difference can always be considered as quarter, half or three quarters of the time between the two steps ( or smaller changes if you're really picky) - and for each individual step these increments will have the same effect i.e. just as stops do for the camera (Leica TTL of course!!) If you compare this with exposure strips made using two second (or 5, or whatever your choice is) the above system covers a much greater exposure range and each time step gives consistent density changes - rather than the fixed time steps where each change in time gives a differing density change. Sorry if that could be put more clearly - but try it next time you're in the dark - Once you've adjusted your way of thinking there is no other way to do it!!! Regards Clive Sanbrook