The "Digital Quality Myth" (Say it ain't so!)
OK - in the previous blogisode my sidekick and ally in presentations Eric Graf exploded many of the make-believe antics that pass for science on those pop cop "CSI" - type soap operas that have the masses convinced that such visual alchemy truly exists.
One of the culprits that I feel has encouraged the feebs who write the CSI tripe is the DVR, or Digital Video Recorder. I've personally witnessed the growth of these machines over the past 5 or 6 years in the surveillance arena and have marveled at the promises made by the manufacturers that hawk them to their unsuspecting customers with the overt promise of the unit being capable of isolating an incident (and any suspect within the incident) and then enlarge said subjects facial features for police identification.
I've had the sad chore of bursting many a security manager's bubble when I point out the REAL limitations of their 32 camera, state of the art, real-time, internet accessable system. I no longer feel the need to let them rest their head on my shoulder anymore while gently rocking them and saying "There, there, it wasn't your fault".
Because, it is their fault. They should know better.
Here's why - Here's Eric's take on what we'll call "The Digital Myth":
DIGITAL IS NOT NECESSARILY BETTER (Regardless of what you've been told)
Actually, I could almost leave out the “necessarily.” There’s this dirty secret about digital video that they don’t tell you. Here it is. Y’ready?
To save space, digital video throws out details of the picture that it doesn’t think you’ll miss.
It’s really obvious on some internet videos, where you’ll see people’s faces disappear into a detail-less blob. Trouble is, nearly all digital video, including DVD, DV tape, TiVO, high-definition broadcast, and (especially) surveillance systems, does the same thing to a certain extent, and it messes up our ability to do some of the cool CSI things we actually can do.
DVDs are particularly bad about this, particularly if you’re using a consumer-grade recorder, and PARTICULARLY if the original source is VHS. VHS has a lot of extraneous "noise" in the picture, and extraneous noise tends to confuse DVD recorders into throwing out more of the important details than they ordinarily would.
Going from analog to digital also has some hazards not directly related to the nature of digital. For instance, every consumer grade DVD recorder we have ever tested, without exception, records the video black level incorrectly. It’s a long story as to why (and if you feel you MUST hear it, you can email me), but the point is that it’s a problem for us, and there’s not a darn thing you can do about it without professional video equipment. (Side note . . . many DV recorders and computer video cards do the same thing.) It’s best to send us the original, and if there are DVDs to be made, let us make them.
Copying digitally (through Firewire) from DV tape to DVD usually goes better, but there’s still quality loss, especially in the color information, because DVD ditches a lot more of the detail info than DV tape does.
YOUR SHINY NEW DIGITAL SURVEILLANCE RECORDER (It's not what you thought it was)
OK, if you have one of these newfangled gizmos, pay very close attention!
Guess how they manage to get a month’s worth of video onto a single hard drive?
That’s right. They toss out everything, even the kitchen sink. And they record the picture at a horrible resolution setting that guarantees that anything smaller than a Peterbilt won’t be recognizable.
If you have your digital device set to record at the maximum time setting, you might as well not waste your electricity. You will not get ANYTHING useful. Period. End of story. We have a lot of would-be clients who learned this the hard way. And sadly, most of the salespeople who handle these things don’t bother telling you this, figuring that you’ll assume (incorrectly) that somebody like us will be able to bail you out when the need arises.
Change those settings now!
Go for the shortest time period and the highest quality you can possibly get away with. Use your own eyeballs and your own common sense. As already discussed, video does not enlarge well, so if you can’t see it on your screen, there’s a good chance we won’t be able see it on ours either.
If you have everything maxed out and still can’t see stuff, consider rethinking the position and coverage of the cameras. Yes, you might miss something if you’re zoomed in too tight, but you’ll miss EVERYTHING if you’re zoomed out too wide. A teeny little blurry picture of a teeny little blurry guy stealing your Bentley isn’t going to help you or the cops or us or the Bentley. If you’re worried about the Bentley, then zoom in on the Bentley! Let the Yugo parked next to it fend for itself.
Stay Tuned.. Our next blogisode will have you questioning everything you believed you knew about AUDIO!
