Frames Missing and/or Jerky Motion During Capture

Whether you are using the 2K camera or the 4K camera, the interface with the PC must be USB3. If you have your camera plugged into a USB2 port - or - a USB3 port with out of date drivers, or a malfunctioning USB3 port, then the software will not receive every frame that is captured by the camera. USB2 cameras should only use cables 5 feet or less in length. Use of USB extension cables on a USB3 camera can also cause problems if the extension cable is actually rated for only USB2 and not USB3.

The difference between "dropped" frames and "missed" frames.

A dropped frame is one that was captured successfully but was dropped by the PC before being written to the drive. This happens because the PC or hard drive was overloaded during capture and could not keep up. Dropped frames will show up in the drop frame counter of the software.


A missed frame is one that was never captured. This typically happens because the sensor was not set correctly or due to bad USB connectivity as described above. On LightPin sensors, this can happen if there is lint or debris on the end of the sensor or if the sensor was not focused properly. On older gates with UV LEDs, this can happen if the sensor level is not set correctly. Missed frames will not show up in the drop frame counter of the software.


Diagnosing missed vs dropped frames: If the dropped frame counter shows no dropped frames but the action seems to run fast or jerky on the screen, first check to see if the software footage counter matches the expected length of the roll. For instance, if you know you have a 50 foot roll and it registers as only, say, 35 feet, then you are either missing frames or dropping frames and the following test can be performed.

Make sure that the green tall light blinks while any film is being run through the unit. Use a short roll of film, such as a 50 foot roll, and have ample leader at both the beginning and end of the roll. Scan the film 3 times, from end to end, making sure that some of the head and tail leader is included in the scan. Export all three scans as a 24p files and import all three onto a 24p project time line. Stack the three files above each other. Find the exact frame in each scan where the head leader meets the film and align all three files. Go to the end of the files and see if the tail leader of all three files also align on the same frame. If they do, then you are not missing any frames. If the action seems to run fast, then that simply means it was accidentally shot that way on those years ago and is built into the film.

If you lower the speed of the unit, reduce the capture resolution to 1.3mp, and capture compressed, the resulting footage should look ok, even on relatively slow PCs. If it seems to play back fast - or - there seems to be a lag on the capture screen, then your system may have a resource issue of some kind, such as bad or too little RAM or some competing app that is interfering with the capture. If working with the new 4K camera, incorrect network card settings can also cause loss of frames as well as lag and jerky motion.


Solutions for "dropped" frames and "missed" frames.

Solutions for dropped frames showing up would be to use the slower speed of the scanner, check to make sure the hard drive is not full or fragmented, and that the drive chosen is fast enough for the given task. Scanning uncompressed may work great at the beginning of an empty drive but, as the drive gets full, you may see dropped frames starting to show up in the drop frame counter. Ideally, drives should be de-fragged regularly and never get beyond about 60% full, even when using solid state drives.


Solutions for missed frames would be to double check the sensor and USB connections. USB ports are notoriously cheap and, over time, a non-conductive film can build up which can cause problems. Sometimes, the easiest solution is to unplug and plug both cable ends a handful of times to scrape away at the metal contacts in the USB port to reestablish sufficient connectivity.

In all cases, avoid capturing to an external drive.

Exporting, however, can be assigned to any drive, whether internal or external.