long exposure with "Auto B"???

Hello,

I have a problem with a Nizo camera that I used for the "Auto B" feature. I used it in low light, but the footage came back completely overexposed !!!... Is the camera not working properly or am I doing something wrong? I thought I simply had to leave the exposure on automatic, set the timer knob on "Auto B", and lock the shutter open...? I don't have a manual, but is there something else I had to do? If this feature is supposed to calculate the time of exposure according to the amount of light, how can it be overexposed, since I use it in the beginning for conditions where there isn't enough light...???

thanks a lot for help!
 
Hello,

no, the meter is not broken since it works fine at normal speed and normal shutter angle, wheter automatic or manual... Has anyone used that Auto B feature on Nizo Super8 cameras? Are we supposed to set the aperture manually? But that would defeat the purpose of the camera automaticaly calculating light vs time of exposure, right? Anyway, I fear it's a camera problem...

thanks to all
 
Addition of the Automatic "B" feature which has a front mounted external photo cell, so that you can set the camera to Automatic "B" to allow the meter to determine the required timed exposure per frame in low light from 1/10th second to 1 minute per frame....or set it to manual.

OK according to this (Martin Baumgarten),you have another front mounted photocell.Maybe you need another battery for it?So if I am to understand correctly,you're shooting time lapse with a timed exposure on each frame from one minute to 1/10th of a second.I'm assuming this meter sets it on an apeture priority,so would you not have to determine an F stop first and let the camera(on this "B auto" setting) choose a shutter speed based on the amount of light and the Fstop you set it on.Or does it automatically set the aperture at wide open and choose a shutter speed based on lighting conditions?

I dunno. I have learned something about timed shutters working with stills.All of my early attempts came out underexposed because I set the Fstop according to what the TTL meter said based on the shutter speed (constant ,I would set it on 1 to several seconds).The meter told me I had plent of light and it made sense to me so I stopped down accordingly.What I did NOT know at the time is that in timed exposures there is something called a "reciprocity factor"that kicks in and makes your meter virtually worthless.One of my still photography buddies put me wise to it.Do a google search on reciprocity factors in still photography timed exposures and set your iris and shutter speeds manually based on the recommendations you find.Good luck and keep us posted.
 
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