Shutter open and close detecting mechanism

Discussion in 'Legacy Models - Community Support' started by golgot78, Jul 5, 2018.

  1. golgot78

    golgot78 Cyanogen Customer

    Joined:
    Sep 19, 2016
    Messages:
    25
    Hello,

    I'm using a SBIG STT-3200ME camera and the exposure time is fixed at 1 second. I am trying to do a millisecond precise imaging so I am using the function that allows to sniff the shutter open signal (indicating when the shutter is open) and when the shutter closed signal (when the shutter closes). When I do an exposure of 1 second, the delay between the shutter open signal and the shutter closed signal is 1,002 seconds.

    I guess that there's a piece of hardware indicating when the shutter is open and when the shutter is closed. How that mecanism works (it's mechanic, electric,...) and where is it (just in middle or there is one in the begining and an other one in the end?) Maybe the position can explain the bias of 20 ms every time I take a photo.

    Thank you in advance!
     
  2. golgot78

    golgot78 Cyanogen Customer

    Joined:
    Sep 19, 2016
    Messages:
    25
    Hello,

    I'm using a SBIG STT-3200ME camera and the exposure time is fixed at 1 second. I am trying to do a millisecond precise imaging so I am using the function that allows to sniff the shutter open signal (indicating when the shutter is open) and when the shutter closed signal (when the shutter closes). When I do an exposure of 1 second, the delay between the shutter open signal and the shutter closed signal is 1,002 seconds.

    I guess that there's a piece of hardware indicating when the shutter is open and when the shutter is closed. How that mecanism works (it's mechanic, electric,...) and where is it (just in middle or there is one in the begining and an other one in the end?) Maybe the position can explain the bias of 20 ms every time I take a photo.

    Thank you in advance!
     
  3. Doug

    Doug Staff Member

    Joined:
    Sep 25, 2014
    Messages:
    9,934
    The shutter does not react instantaneously; it's a rotating shutter so it takes a finite amount of time to actuate. You might want to use the hardware output signal.

    Just a thought... MaxIm DL has a shutter calibration feature. Once you make the measurement, MaxIm DL will automatically record the exposure time to more precision, and account for the shutter delay.

    See http://www.diffractionlimited.com/help/maximdl/Shutter_Latency_Measurement.htm
     
  4. golgot78

    golgot78 Cyanogen Customer

    Joined:
    Sep 19, 2016
    Messages:
    25
    Hi Doug,

    I agree about the shutter delay, so I am listening to the hardware output signal indicating that the shutter is open. The delay between the hardware output signal indicating that the shutter is open and the signal indicating that the shutter is closed is not 1 second but 1,002 seconds.

    There's a delay of 20 ms because I take an exposure of 1 second. I would like to identify the origin of the delay, that is why I'm asking how that mecanism works (if it's mechanic or electric,...) and where is it placed.

    Thank you,
     
  5. Doug

    Doug Staff Member

    Joined:
    Sep 25, 2014
    Messages:
    9,934
    The shutter control signals and hardware output signals are generated by the camera's FPGA.
     

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