The ST4 is moving during my timelapse exposure - Understanding the Shot Cycle

Is your ST4 moving to the next frame while your shutter is open?  Do you just want to better understand the shot cycle and what the ST4 is doing?  You are in the right place.

Terms:

Camera Shutter Time (Exposure Time) - Start here and understand how you want to balance your exposure. Just like everything else that can change during an exposure, set it up and lock it down on your camera. Do a test shot for your lighting and know your exposure time before trying to program a shot.

Interval -  is your frame rate for time lapse or stop-frame animation. If you select a 2.0 second interval, the eMotimo spectrum will trigger your camera to start a shot every 2.0 seconds. If you want to speed time more, select a longer interval (good for shots taken over a long duration of time). If you want to speed time less, select a smaller interval (good for shots taken over a short duration of time). Interval time always needs to be set longer than the exposure time set on your camera. TIP: When shooting long exposures, set your interval to twice your camera’s shutter speed.

Static time -  Always needs to be less than your interval.  Static time is the amount of time the spectrum remains stationary (static) and triggers your camera’s shutter before it moves. This setting prevents the ST4 from moving during your exposure.   For setting the correct static time, start with you your camera’s exposure time and add 0.1 or 0.2 seconds onto it. For example, if you are shooting a 2.0 second exposure, select a 2.2 second static time. If you are shooting daytime shots with 1/100th sec. exposure, use default of 0.2 seconds static time.  

Here are some good sample parameters:

Some quick guidance:

1. Know you camera's exposure going in to programming a timelapse shot.
2. Make sure your camera's shutter speed is set less than your ST4′s static time.
3. Make sure your cameras shutter speed is set less than your ST4′s interval time
4. In general, understand the shot cycle – the ST4is smart, but needs your help to program it correctly. Your camera’s exposure time, the ST4′s intervals, and Static time are interrelated in a tightly choreographed dance we like to call – The Anatomy of a Single SMS Frame – Check it
   
   

Still having issues, then reach out to support with some good info and the following video.

Setup the following shot on a spectrum with the latest released firmware.
1)  Big Pan/Tilt that we can see actual movement on between shots (Say 45 degree pan and tilt.
2)  Interval 64 sec, Static Time 32 sec, Cam Exp time 30.0 sec. (or whatever combination was causing you issue.)  Record ALL the parameters and pass this back with the video
3)  Total shots, - 50
4)  Make sure AF is off on your camera

From behind, we need to see and HEAR the following video shot from behind the rig:
5)  We need to see the ST4 OLED screen, and hear the camera shutter for at least 10 cycles.  Keep in mind that if you have a processing issue, this will likely shot up later in your shot, not at the beginning.  Better yet, record the full setup showing the ST4 screen from startup.

We also want and need:

6)  The TL sequence from the camera that was doing the timelapse.

On review, we are looking for the indication that the spectrum is attempting to fire the cameras (upper right circles in the OLED screen) and seeing when and how quickly your camera responds.  If its not immediate, there is an issue, with camera not accepting trigger.  This will add up and cause issues as the move timing can then happen mid exposure.

We will also see how long your camera's 30 second exposure really is (its not always exactly 30 seconds), and how long your processing light stays on to give us clues.