Nice mirror box - anybody tried?

[Kaspar Kallas]

3D Film Factory. Creating dynamic entertainment*for a new dimension.

Seems really nice, don't want to start re-inventing the bicycle if one is available for "sane" price.

Thank You
-Kaspar

[Adam Stanislav]

Depends on what price is sane for you. You may even build one of those (or have someone build one for you) by using a stereoscopic mirror.

[Kaspar Kallas]

Hi

well the mirror would be 500 then you need to get
1. the standard aluminum parts 200/300?
2. Plastic parts and cutting 100/200?
3. The camera mounts CNC'd 2 at least 2 pieces each plus tightening 1K?
4. My time spent developing this, figuring out all the dont's (Expensive!)

So we got at least 2K worth of parts only on the INDY rig - for me it is a good deal and it seems to have everything I would need to use it in professional shoot.
Unlike the PS rig that will start to fall appart under SI2K with Ultra16 lenses let alone something heavy (and they are muy expenisvo).

-Kaspar

[Matti Poutanen]

Yeah i´m with Kaspar with this one: the price seems very reasonable (for professional production). If the craftmanship is good and it is rugged for field production, it should be a good investment.

Kaspar: how´s 3D filming doing in Estonia? I´m from Finland and prepping (at the moment we´re rolling in the summer of 2011 so I have the luxury which is not usually possible: time to do decent prep!) a feature to be shot with 2 Reds in 3D, maybe we can chat about your experiences as you are a lot more experienced in the than I.

[Alister Chapman]

I just purchased a new 50/50 color corrected mirror for one of my home built rigs and it cost me $90 inc shipping from the US to UK. Even a big mirror isn't going to cost much more than $150. Beam splitter rigs are straight forward to make. The film factory rigs are made from off the shelf alloy extrusions, the only special parts are the mounting plates. My current rig (2x EX3's) cost about $500 in parts including the off the shelf camera sliding plates that allow for instant inter-axial adjustment and camera quick release. Obviously the cost doesn't include my time, the rig took about 3 days to construct. The best bit for me is that it has the features I want, including light weight, easy to dismantle for transport, single v-lock battery and mounting for a Nano3D system.

[Pete Murphy]

I would be curious to hear where you purchased your mirror. "color corrected" implies some are not. Do you think these ones at Edmunds Scientific would be for instance?
Plate Beamsplitters - Edmund Optics
They say they are "very neutral".

btw I am mainly interested in "multiview" videos -- with camera arrays -- for autostereoscopic displays. With my 10 camera rig

I do stills at the moment .. like these ..
http://www.mediavr.com/ronald.htm (this collection of frames appears 3d when interlaced on an autostereo dispaly) ... but I working on multiview movies too but the sync problems are more complex (I use Canon compacts and Stereodata Maker software for still syncing). Most autostereo displays have a very shallow depth budget so your cameras have to be very close together. Mirror boxes are one solution. So for instance you could have 5 cameras looking ahead and 4 cameras looking down with a mirror box to halve your camera separation. So you would need a quite wide format mirror.)

Peter Murphy

[Adam Stanislav]

Pete, the link I posted above is for beam splitter mirrors made specifically for 3D which requires better quality than a generic beam splitter. I seriously doubt the Edmund Scientific mirrors are good for 3D. Essentially, unless they say explicitly it is for 3D stereoscopy, it probably is not.

[Bicky Singh]

Hey Alister,

I'm curious to see the beam splitter rig you made for your EX3, do you mind sharing any pictures? How light-weight is it when you've got the two ex-3's on it?

I'd really like to get my hands on a lightweight handheld/steadicam BS rig. The ones that are being sold are quite expensive. I've always wondered how hard it might be to make one yourself like you have done.

[Alister Chapman]

Here are some pictures of the full rig, complete with 3D production monitor and NanoFlashes. For hand held I would strip it down to the basics. The rig itself (without cameras) is made from aircraft grade aluminum and is just over 9lbs. With an EX1, EX3 and single 90Wh V-lock battery it is approx 26lbs (13kg). It is very front heavy but you can use a waist support and I use a twin handle grip, so it's not too bad for short shooting periods. Next time I use it hand held I'll get some pictures taken.

[Adam Stanislav]

This is very nice, Alister. Thanks for posting those pictures!

[Sareesh Sudhakaran]

alister...great pictures
How does one shoot handheld on these and still keep focus on both cameras?

[Bicky Singh]

Great rig for sure, Alister. Thanks for sharing.

What type of inter-axial distance can you achieve with that rig?

Are you willing to build and sell them or help us build our own with some DIY instructions?

[Alister Chapman]

I can go from zero separation to 100mm interaxial with the mirror box currently fitted. A bigger mirror would allow for greater range. When I get a chance I'll take some more detailed pictures so you can see how it's put together.

The main chassis is made from 5"x2" Aluminium U channel. The cameras are mounted using Bogen quick release adapters with sliding plates. For the top camera the QR mount is turned through 90 degrees which allows me to slide the camera from side to side to adjust the interaxial. Camera tilt and skew is adjusted with set screws that act on the underside of the QR mounts.

Rather than trying to construct a mirror box with an adjustable mirror I have fixed the mirror in the box. The mirror box is then attached to the chassis by 1"x1" L section alloy and I use small set screws to at the bottom of the mirror box to tilt and twist the entire mirror box relative to the chassis, it's crude but very effective.

For handheld I attach a pair of handles either side of the lower camera and strip off all the excess bits like the monitor. At the moment focus is pretty much impossible to do by yourself handheld. I'm trying to find a good dual wireless follow focus system. I'll have the rig on the Convergent Design booth at NAB if anyone wants to take a look.

[Bruce Schultz]

Alister,

I've got the exact same rig going with 2 EX cameras and I've been searching for a follow focus solution also. I've visited Preston Cinema here in Los Angeles and they have designed a wireless dual channel system for me to use with the EX cameras. It's not cheap, but then what is in pro video these days? Anyway, I'll print out the sales order and bring it to show you at NAB next week. I also use 2 Nano Flash units so I'm most interested seeing in the Nano 3D kit at the C-D booth.

[Karl Kozak]

The mirror is actually the heart of any good rig. So - buying a "big mirror" for $150 is NOT what you want to do. The mirror that Chapman is speaking of is a piece of teleprompter grade glass. This stuff will cause you more grief and bad 3D than you can imagine. Don't use it.

The quailty of your mirror on a beam-splitter is everything. A 3D rig merely holds the cameras in place once aligned. So at the 3D Film Factory we go to great lengths to acquire high-quality, beam-splitter glass. That means glass that's very flat, clear (impurity and iron free) and has a high-grade 50/50 Optimized for 45 degrees - among other qualities.

So before you rush out and just grab a piece of glass - stop and do your homework.