shooting computer monitors - live images or add in post?
so i know this is a common issue so i wanted to get a consensus from some more experienced members who have dealt with this before on shooting in a room with monitors or computer screens in it.
in a nutshell, we're shooting in a security room which will be full of many screens displaying various video loops. it would make my life a lot easier if i could just create these loops ahead of filming, and have them setup to play on all the screens so that we just film it in camera and it's done, but i'm afraid of it flickering or otherwise looking low quality. i know this was an issue back with older monitors like crt's but is it still a problem today? many of the posts i saw about this were almost 10 years old and i wonder if newer cameras and displays have overcome this.
we're shooting on an ARRI Alexa, 24fps at 1080. the monitors aren't set yet so we could use whatever works best. for close ups or shots of action not yet shot, i plan to add the screens in post anyway, but what i want to avoid is having to track and composite a dozen screens in every single shot, even when they're in the background (worse still, out of focus!).
so is this possible, or just a pipedream? is there a standard professional practice for handling when there are tv's or monitors in a scene - especially if they're just a background element in many shots?
You can certainly do it either way... practical screens or screens replaced in post. We've done plenty of it both ways. Each has its own advantages and disadvantages... and sometimes one way is better for a particular shot or setup, and a different way better for another one.
When doing it practically, this is not as big an issue as it was years ago, with film shoots and CRT monitors. Those days required special 24-frame playback monitors, and there were a couple of Hollywood supply houses that had special 24fps monitors in just about every conceivable TV brand and style. That's just not needed anymore.
Firstly, it's very likely you'll have LCD, LED, or plasma monitors. These do not nearly have the flicker issues of old CRTs (and certainly none of the "rolling"). Plasma monitors in particular I found work best when I shoot 35mm film.
Secondly, these days all you really need is a camera that can shoot in "clearscan mode," where you dial in a very exact and precise shutter speed (note: not frame rate, but shutter speed) that will completely eliminate any flickering or phasing. The Alexa will certainly do that.
Whenever we've shot practical monitors we've usually done it two ways with the same setup. First we'll shoot the scene practically. Then we'll shoot another take or two but with the monitors displaying a pure green screen. That gives us lots of flexibility... if the practical version works, great. But if not, the greenscreen version makes it easy to replace the screens.
Doing it in post generally looks better, and you have perfect control over the timing and content of the monitors. It's certainly more labor intensive though, as just replacing the screens straight looks so phony. You've got a lot of issues like tweaking chroma, brightness and contrast to make it look real, motion tracking, adding reflections, and all that jazz. We've found though that most of the time it seems the replaced monitors just look a lot better.
Here's a couple of recent samples we did for one credit union client...
This iPad screen is practical...
...whereas this one is fake, replaced in post...
...and the smartphone screen in this was replaced...
...and the laptop screen here was replaced...
So, you can certainly do it either way.
Fantastic Plastic Entertainment, Inc.
If you're going to play green or blue video on the screens, be sure you don't crank up the brightness so much that the green spills around the bezels and frames, or you're just making extra work to mask things out.
To help with motion tracking, adding some tape dots on the screens will give mocha of other software an easier track.
Todd, LOVED the fake beach. Very convincing.
Personally I've found that whenever we did the "Ok let's get one green screen version just in case..." bit, that almost invariably that's what we end up using. Almost without fail.
And on a side note... thanks Mark. Previously with a different client we also needed a beach shot. This is a client we love because they literally drip money and, even better, they've never heard a bad idea. Ever. The only way to really get the scene they needed was for us to actually go to the coast (nearest beach is the Gulf of Mexico, about 8 hours away). So we spent about four days down in Florida.
I think the actual shoot lasted, hmmm, maybe 90 minutes.
This credit union client was not quite as gullible. Dang.
Fantastic Plastic Entertainment, Inc.
Todd, thank you so much for this incredibly helpful and comprehensive answer to my questions, i think this gives me a much better idea of what is possible. we have access to the camera so i'll make sure we do a few test shots before the shoot with live and green to see how they look.
i looked at your examples and i was wondering if i might ask you how you added the reflection to the faked ipad screen? is it a still or video and how did you deal with it changing as she moved the device? i've read that the human brain is not very good at picking up on the accuracy of reflection as long as it's close to correct giving you a lot of freedom to fudge things like this.
Mark, you make a good point, considering this is probably going to be a fairly dim room we'll probably keep the monitors on the lowest brightness to reduce spill and keep them as close as possible to the rest of the light values in the scene
Just came across your post. I would highly recommend mocha which is a planar tracking software bundled free with After Effects OR available as a stand alone called mocha Pro.
For tracking in screens, mocha excels and very often you do not need green screens or markers. This can be most useful for compositing back in reflections for realism.
This is a link found on the mocha site of a Conan O'Brien spot with tons of difficult screen replacements: http://www.imagineersystems.com/case-studies-folder/big-sky-effects-tracks-...
You can also find may free tutorials to help get started.
Lastly, Hollywood Camera Work has a nice video that explains how to shoot for planar tracking at the bottom of this page link:
Thanks Ross, i agree that mocha pro is a fantastic tracking solution which i've been using for some time now and we will be making use of it in our pipeline. i know it would be most 'professional' so to speak to do these in post and that was my original thought, but i simply wanted to know if it was possible to do screens practical and at what cost to quality. the team we have for vfx is quite small and the scope of the project is very large and our deadlines will be very tight so anything i can do to save several days of post will be a godsend.
i've also watched the all the hollywood camera work dvds and they are an absolutely fantastic resource. i do know i can just track without screens to capture natural reflections but the reason i asked todd about his technique for adding reflection in post is that it is not always practical to capture real reflection off a glossy mirror like surface such as an ipad because it will often reflect your crew, camera and lighting so faking the reflection is best.
The iPad reflection was motion video that was taken from another shot of the actress... if I recall I believe it was from the same setup as the previous shot in the spot (although with a longer lens). It wasn't a shot that was specifically shot for reflection (we didn't do that or sadly even think of it at the time), but just a shot our editor grabbed to use.
This shot was just ghosted and motion tracked over the "main" iPad video, and then some more moving white reflections were added, too. The video that was the main desktop content of the iPad was created after the rough cut of the spot was done, so we would know exactly what the screen needed to do at what timing.
I believe (I'm not sure, my editor cut that spot) that the main iPad content was tracked with Mocha CS6, whereas the reflections were just hand tracked with Premiere Motion so they would be a bit looser and not quite locked in with the Mocha tracking.
And yes, the human brain is pretty forgiving of the reflections. Just watching that spot, the reflections look fine. But if you play it slow or stop it and analyze the scene, our reflections are really pretty terrible. You'd never actually see a reflection of that actress' face in an iPad shot from that angle and held in that position... at best you'd see the actor next to her, but most likely you'd just see sky (or rather, the big butterfly frame overhead). And while you see her face reflected, you don't see her hand as she works the iPad. But the shots are so short (I think each of the two shots is only about 20 frames each) that it goes by before your brain has a chance to say "Hey, that's not right." On the other hand, without even our sloppy reflections it would look very phony.
If the shots had been longer, we would probably have taken more time to get them "right."
You see "incorrect" reflections all the time in movies and TV shows... reflections that either wouldn't actually quite be like that in real life, or just plain impossible.
Fantastic Plastic Entertainment, Inc.