Getting a Clock into Your Interview Recordings

Is there a clock in your recorded interviews? Here's one solution that worked wonders.

If you know a better one? Share it in the comments!

Logistical Concerns

Once we made the decision to begin video recording all LP interviews it came with logistical concerns, not the least of which was measuring time inside of the recorded video. Using the counters on the playback software implied that there would be no differences between software applications, and that those counters would be visible during playback. Often when an image is in full screen mode the administrative border data disappears. The solution? Find a way to get a clock into the recording image space. The problem then shifted to getting power to a clock and placing it where it was visible, but not conspicuous or distracting. Let's all be honest, in a retail environment without a dedicated interview room no one wants to spend too much time setting up for an interview. The interview is already a disruption to operations at that location, thus the time necessary for the interview, from space preparation through to completion and departure, needs to be used as economically as possible. A portable and battery-operated solution became the goal. Would an analog clock be acceptable? After all, there are many battery-operated analog clock options. If not, how large should the numbers be on a digital clock to be readily visible, but still not overly conspicuous in the video? After a few experiments with printed images of digital clocks, it looked like 3" to 4" tall numbers would be the goal.

We dismissed an analog clock solution. Why? It was certainly an easier solution, however it simply did not offer an easy time reference with quick precision. Consider trying to describe any aspect of time in court based on an analog clock versus a digital clock. There was no reason to create one more opportunity for an adversarial attorney to hassle our witness.

            

Finding a Digital Solution

Unfortunately, finding a battery-operated digital clock with numbers at least three inches tall was something of a unicorn. Web searches were not fruitful. Test purchases had disappointing results, and came with annoying product returns. Frustration is not something I care for, and it may be proof that "necessity is the mother of invention." After some trolling through retail stores an idea floated up.

An ordinary bedside alarm clock with a sufficiently sized display that also had a battery backup for power-outages might do the trick. Once back at the office with the specimen, it was quickly disassembled and the math started. The battery backup was a 9-volt battery and was meant to support the alarm clock. A closer review of the circuit (logic) board implied that a 6-volt battery should support just the clock. Spare components were cut free, speaker, AC power connection, all tossed back in the box. There was no turning back at this point. We tested a 6-volt battery pack of four AA batteries that supported the clock operations well enough, and the clock seemed accurate.

To contain this Franken-clock a lunch container was also sacrificed. This "proof of concept" version, including the lunch container, was quickly attached to the wall with 3M Command Strips. While it proved the concept in a rather simple way, it was ugly, a little ungainly for portable use, but a success.

Operations and Forensic Testing

To ensure both the endurance of the 6-volt battery pack and the accuracy of the clock over time, we rigged it next to an analog clock in view of a camera and left it to run overnight. The test confirmed that the clock remained accurate and the battery pack ran roughly six hours. With the office lights out, the slow fail of the clock was quite apparent. Of note to the test was the wear those particular batteries had already endured in the preparation which made the test of battery life very conservative. Endurance of four hours would be more than sufficient for any of our interviews. Since the clock used common batteries, finding spares nearly anywhere should not be a problem if more than one interview was necessary in a row.

The video of this test was also burned to a DVD to create an indelible version. This was maintained should anyone challenge the accuracy of the clock, but that did not happen in over half of a decade. While we did not do it at the time of the recording, I would recommend getting a hash value for such a file. A hash value of a file can be used to show the authenticity of any copies, regardless of the media on which they may be stored. There are free hashing services online, and these values may be replicated at a later time to show the "identical-ness" of any copies. The same can be done of any recorded interview videos as well.

What's Inside?

With a working model to build from, a smaller container was quickly found. Interestingly the containers were originally used for shipping an unrelated component by a distributor. We found these containers to be immensely versatile and used them for subsequent solutions as well. The distributor happily shipped a batch to us.

The single largest component looted from the original clock was the display screen. The screen and the top outside surface of the container were the same size. As I said, extremely versatile. Attaching the screen outside the container came with the risk of damage, and a few years later a unit was handled roughly by an investigator resulting it sufficient damage to make unrepairable. With three units in operation for years I think the damage might be a better statement on the investigators diligence than on the fragility of the clock.

The logic board from the clock was attached to the inside of the container with the display flat wire passing through a small hole to the display. A "9-volt" connector was soldered to the the logic board power wires, and a "9-volt" connector was soldered to the battery pack. The connector on the logic board was soldered to reverse the polarity allowing it to mate properly with the battery pack connector.

Lastly, a handful of velcro 3M Command Strips were added to the container. The Command Strips made for a convenient way to attach the clock to nearby walls without damaging the paint. There was also sufficient space in the container for one or two sets of spare batteries. Although, preserving battery life was as simple as disconnecting the batteries when the unit was not in use.


How Does it Look in Routine Operation?

The clocks quickly became a very useful part of the video collected from interviews. It further made it easier to reference periods within the interview in the written reports. Any still image added to written reports were easily cross-referenced by the reader.

Decide for yourself whether it was worth the effort:

There is likely a better solution available, but we never found it.

If you found this helpful like the post, and if you know of better solution please share it in a comment.