once more for autom. B!
Posted 03 March 2006 - 04:58 AM
Posted 03 March 2006 - 01:35 PM
OK - I'm shooting at night, I set the aperture control manually on my nizo 561 macro closing it 2 stops for greater depth of field, then I set the run control to autom. B, open the shutter all the way and lock it. Will the autom. B function take into account the aperture I've set and correctly expose the frames accordingly? or can it only be used when the aperture control is set to auto? sorry if I seem to be repeating myself but I don't have a manual - you're my only hope! (that and wasting a bit of film experimenting)
You can probably do a simple auto B test to know for sure. Using a dimly lit or night time set-up, put the camera on a tripod, set the camera's f-stop wide open, and time the duration that the shutter is open. Then without changing the lighting or the frame, move the f-stop a couple of stops and see if the duration time changes. If the time interval does not change, then you know that the f-stop setting and duration are not linked.
If you would like to bypass the Auto B setting and set the time-exposure length and f-stop yourself but don't know what to set it at, here's a simple formula to consider. f 2.8 = 3 seconds, F 4.0 = 4 seconds, F 5.6 = 5-6 seconds. Notate which three duration you have selected and then after testing all three see which duration you like the most when you see the results after the film is processed. These three combinations are easy to remember and will get you in the ballpark in terms of something useable.
The way you frame the shot will have an influence as to what f-stop and duration you end up liking most. You may find that you like F5.6 at 5-6 seconds for a wide shot, but then for a closer up shot you may find that you like F2.8 at 3 seconds. You may ultimately find that you like a different combination then the easy to remember ones that I have suggested.