Home of Professional Cinematography since 1996

Filming Background Plates

>Hi,

>I'm working on a commercial for TGV trains. What's happened is we have shot the interior of this great (and Big) apartment in a studio. The apartment has huge windows through which we are going to see the landscape passing. Now the post house have been on set the whole time (this is all a bit complicated because we have shot the interior element's first and now we are going to shoot the background plates). The guy at the post house wants to use three cameras "Cinerama style" to get a 180 deg angle of view and a massive negative. I am more than happy to oblige

>I was wondering if anyone on the list has done this before :

>We have sorted the "Phasing" problem (in Theory) and will use TC for speed of sync. Anyone got any other tips ?

Justin Pentecost -CML Listpig

Focus Puller

London


>DON'T make the mistake of shooting the landscape you see out the windows SHARP. It really bugs me to see otherwise impeccable productions with everything hairsharp. Take time to do the computation what degree of sharpness you need in every shot, considering the position of talent etc.

Robert Rouveroy csc

The Hague, Holland


>I don't see how you can shoot 180 deg view of passing landscape from within the train and there very well may be a disconcerting effect from seeing a 180 view out a window that your mind tells you should only provide 90 degrees. Not that there's anything wrong with that.

>If your shooting three cameras on a moving train that will be mated to form a seamless background, you may want to consider mounting the cameras on the same support system so that they all vibrate in unison. Like mounting them directly to an I beam.

>Because your going to TV....you'd probably get the same final results, tho not have as much fun, by shooting S35 with a "wide ass lens".

>Glenn Suprenard


>Justin,

>Sounds like you are well on your way to a creative answer to your spicy challenge.

>If you need help with syncing the phasing of multiple cameras you might try Terry West (gifted in house tech at Otto Nemenz, LA). He successfully linked multiple (was it 12?) Arri IIIs for a music video using Otto gear. Good luck.

>David Campbell


>We've done exactly this thing several times, most notably for Under Siege 2: Dark Terrirtory and recently for cockpit scenes in MI-2. In the case of both of these, we were shooting for digital comps for wide screen release. We used Vista Vision (three cameras for 180 degrees) and 65mm (two cameras for nearly 180 degrees) on these projects. We have also done this sort of thing for finishing in TV res using 35mm ffor circle-vision type special venue work. Several things to note:

>AsGlenn noted, you do want to mount all cameras on a common mounting plate (I have some available for a small fee:-) (just kidding - it is probably not worth shipping this much aluminum - buy your own:-)(well, actually, I do have what you need for this email me privately if you want more info) Phasing is vital if you have anything passing close to camera, since phase offsets will result in horizontal travel offsets of those objects at the boundries

>I would talk to the post house about sharpness - I would strongly suggest shooting the backgrounds sharp and letting them fuzz them in post and NOT do that in the camera. If you watch Under Siege 2, I defy you to tell which of the 39 minutes of the film is shot on my stage with our plates and which were shot on the train itself - and focus won't tell you:-) (Hint: if the lighting looks right, it must be on stage, because it is VERY hard to light a tinted-window train when you can't rig outside it because of federal transportation laws and tunnels)

>Jim Dickson, a well known commercial and VFX DP (he shot the"Movie Magic" Showscan film that was talked about on the list a couple of weeks ago) has built a multi camera rig that shoots up into mirrors like the old circle vision rig but with very small interocular distances and modular for varying numbers of cameras depending on the F.O.V that you need. It has just been used for a film mounted on a sidecar rig going down a runway at an airport. He also did a 9 camera rig for a TV res special venue show we worked on (I did the power, trigger, and bloop light harnesses) FOr what you need to do, hard mounting the cameras on a BEEFY braced aluminum (or aluminium) plate should work, because you should not suffer from Parallax issues too much - anything close enough to the cameras to show parallax is probably motion-blurred or strobed enough to get rid of the problem The devil is in the details.

> If you are going to have parallax problems, you should email Jim, and see if you can get him and his rig. It uses Arri 3's or 435's I would probably shy away from super wide lenses and trying to do it in one or two because of the lens distortion issues. Do NOT use heads under the cameras. Mount them hard You can get levelling heads (like the ones on Chapman dollies and bolt them to a plate and bolt the cameras directly to them...that way you have fine tilt adjustment but a sturdy mount. Are you shooting the plates from a train, or from a bogey-wheel equipped truck?

>I don't get kickbacks from Jim nor do I make enough money renting my multi-camera rigs to pay for their storage, but when you need-em, you need em

>Addendum: I would recommend that you devise a manual optical bloop-light system (email me privately and I can rent you one or tell you how to build it) so that you can slate takes with one or two bloops at head and tail - time code is great...but if it ain't working, the footage will be really miserable to try and sync.I've built a number of bloop systems that clamp to the eyepiece and fog via the viewing system.


>Heh - I'm just about recovered from compositing those very M:I-2 shots myself, with the 3 plates. No - seriously, I think the shots came out fine, and the "3 plate" technique posed no problems in this case. Mark - I hope you liked the final comps.

>This is a great method for certain situations - especially if you need to shoot the backgrounds first, and then subsequently shoot foreground "interiors" with a mobile camera. If you have a "panoramic" plate made up of 3 vista plates stitched together, and you have the ability to motion track in post the movement of the foreground camera, and then apply that movement around your panoramic background plate, then that's a powerful tool. It's well demonstrated in the train interior scenes in Mission: Impossible (1), Under Siege (2) (both vfx supervised by Richard Yuricich), and probably other movies by now. It's a good "belt and braces" solution, especially, as I said, if you don't know what the final camera move on the foreground is going to be. If you have one plate looking to the left side, one looking forward and one looking right, then you've covered most eventualities, right?

>Problems I'd look out for include camera unsteadiness between the three plates (solved as noted elsewhere in this thread by using a common mounting plate). I did some work on a special venue picture where 3 65mm cameras were mounted on a helicopter. On projection (yes, with 3 70mm projectors) the shake between the 3 panels was pretty offensive, and so we steadied all 3 digitally. Not an ideal solution, financially!

>Also, if you are trying to cover a particularly wide angle by using wider lenses, then be aware that lens distortion may start to be an issue. That is - when your lovely post house has stitched the 3 plates together, lines that should be straight, or follow smooth arcs may seem to be "pinched in" towards the seams between the plates. Analysing and removing this distortion can prove tricky - we've been through this before, and so have special software for this, but this may not be the case everywhere.

>Re the focus issue that was mentioned in this thread - I'd say, to cover all possible scenarios, shoot sharp. You then have the option to stay sharp, or defocus in post, pull focus, whatever. That's what was done on M:I-2. One point I'd make, however (and this is a particular bugbear of mine) is that most of the time compositing artists use a type of blurring technique that looks totally fake. This is getting better - many software packages are beginning to offer better defocus techniques. But still, I see shots all the time in movies that cry out "This is a bad comp shot" just because the compositor can't tell the difference between a soggy old digital smudge and a proper circle of confusion.

Paddy Eason

Computer Film Company,

London

http://www.cfc.co.uk