Whenever I see someone investigating and surveilling someone in movies and TV shows, they’re ALWAYS using a still camera instead of a video camera. They often take a lot of rapid photos in sequence as well (click click click click click…). But these days wouldn’t it make more sense to use a video camera? There are lenses to zoom in with video just like still cameras. Obviously I’m talking about modern investigations, not some film noir PI from the '40s.
If you’re a modern PI or FBI agent or whatnot, and you’re sitting in a car surveilling a suspect from afar, wouldn’t it make more sense to use a video camera as opposed to snapping photos with a still camera? You can always get still photos from video, but not the other way around. If you’re going to record their actions I can’t think of any advantage of using a still camera. Yet I don’t think I’ve ever seen an investigator video someone in a movie or tv show. Always snapping the photos. Click click click. Is this just a hollywood cliché or is there something I’m missing?
Top end commercial still cameras can do 20Mpixel; top end video is 1080p, or about 2Mp. The quality zoom lenses for still are far more variable and adjustable - since they have to focus into 10 times the detail; the more expensive ones have good aperture, meaning the ens itself is wider, gathers more light, can get a better picture in less time or lower light. And, of course, you can crop much closed and still get decent detail. The exposure level vs. shutter speed is adjustable on still cameras - you can get sharper pics of things or people in motion. Watch a slow-down of a video sometime, like a sports replay - the individual frames are remarkably blurred, because the video camera does not need to expose slower than 1/60th of a second. In fact, video techs have found that a sequence of sharp pictures looks awful played back - you get a stroboscopic effect where things seem jumpy. The slightly blurred motion looks better in playback, but of course the still frames are far less useful for what surveillance would like. Modern still cameras can typically take 5 or 6 frames a second, so the odds you would miss anything with that rate is low; if you are trying to get a good “face” shot, that should catch any instance where the face turns toward you momentarily.
While some digital cameras have to go “click-click-click” because the mirror moves out of the way and there may be a mechanical shutter, on many digital cameras the sound effect is for show and to tell you what the camera is doing, and can be turned off.
In reality for most surveillance how far away do you really need to be? In a crowded city probably not that far. No need to hide two miles away.
Also, when you have a big zoom lens does it really make much of a difference if the camera itself is 2mp or 6mp? You’ll have a bigger picture with 6mp but not necessarily clearer. The lens can only focus so well from a far distance. At least that’s how it seems, i admit I don’t know too much about the intricacies of this subject.
Light input will, though, as is the amount of raw data being generated. One frame is nearly 40 MB, you have to have a data bus capable of pushing 450MB/sec, and you’ll generate over 1.5TB of data per hour. While you could certainly set up a rig capable of recording a day’s worth of video, it’s gotta be cheaper to pay someone to sit behind the lens and wait for something to happen.
The typical full frame DSLR currently is around 20MP, so yes, the difference is quite large. I don’t know if it matters much in the realm of surveillance but a 2MP image isn’t nearly as versatile as a 20MP image, no matter the zoom.
I can’t speak for the criminal context, but in civil litigation it’s all about context. Physicians and factfinders want to see people who are purportedly disabled moving around, not just standing in a position they shouldn’t be. For all they know, they’re bent at the waist because their back just went out or something. Plus, it’s generally much easier to identify a person from video than it is from a still photograph; it’s pretty hard for them to deny it’s them if the shot pans over to a view of their house and car and kids.
Slight nitpick: It’s more than that, without even going into medium format digital cameras. For example the Nikon D800 is 36MP. Even the Nikon prosumer and consumer dSLRs like the D610 and D7100 are at 24MP.
If you want to show someone in motion - video. If you just need a picture of the person’s face, or what they are handing to the other person, then 20+Mp will trump 2Mp every time. So if you don’t need massive clarity and the ability to zoom in on details afterwards, video is fine. But if you need detail, stills at 6 pics a seconds beats blurrier at 30 frames/sec.
Yes, we’re reaching the point where the pixels matter less because the lenses can only focus so sharp - for high end still cameras. You still get more detail. Unless you are spending a fortune or going for specialized equipment, there’s not as much choice for video. If you’re going for discrete, a tiny still camera does a much much better job than a tiny video camera. Still cameras tend to have a more more options to manually adjust focus, exposure levels, etc.
As for photoshop - any manipulation of images related to a court case to change the content is a serious crime. Not sure what the penalties are, but perjury is good for up to 7 years typically, and the person who took the photos is expected to testify they are correct - so add that to whatever other charges. I can’t imagine why in a non-legal setting (“follow my wife, tell me who she sees”) there would be a need to photoshop, after all the guy is hiring you to tell him the truth, if you can’t do that, what’s the point? He can make his own fake photoshops without hiring a detective.
Several years ago I saw something on TV where these UFO guys were trying to film Area 51 from afar, and they had a video camera hooked up to a HUGE (like 2-3 feet long) zoom lens. They didn’t get any video of aliens and the video they took was still from something like 5 miles away and very blurry - but it was blurry because of the distance and the lens, not because it was 2MP instead of 40MP. They also use(d) these types of zoom lenses to film the space shuttle launches. They were able to follow it up many miles, practically into space. Obviously sitting in a car with a 3 foot zoom lens is conspicuous but still.