6:1 Aspect Ratio projection ...4k enough?

[Joao Miguel Luis]

Hello everyone,

I've been asked to make video images to be projected on a gigantic screen that as a height of 3meters by 18meteres long. I have still not met with the company responsible for the installation, for the full technical specs, but what I understood from my client's first contact is that the projection is composed of actual 7 projectors that compose the image splitting the signal between them through out the entire screen.

I will shoot this with a RED, but since this is such a wierd format I'm not sure if it's actually enough, what aspect ratio is best (16:9 or 2:1) and what other special issues I should be aware off, executing this project.

Any ideas are much appreciated.

Thanks

 

[Stephen Gentle]

You could do a Peter Jackson and make a rig to shoot three RED ONEs at 2:1 side-by-side to get 6:1...

What is the actual pixel resolution across the entire width of the screen?

 

[Michael Hastings]

Stephen's idea is probably best but even shooting 2 red cameras would dramatically increase your overall resolution. If you figured that 1080P/2K resolution was "good enough" with two reds you would have over 8000 pixels wide which is the equivalent of 4 cameras that shoot 2K.

 

[jbeale]

I think it is important to know from what distance people will be viewing the screen. If it's the kind of museum display where people can walk right up to it, the added resolution will be useful, but I'd think 4k is adequate if it's only seen from a long distance, regardless of the actual dimensions of the screen. (Same principle as billboards, they are huge, but low resolution in terms of DPI.)

 

[Joao Miguel Luis]

Thank you guys.

The rig with 2 cameras might be an option I agree, but definitely we're still missing some key information to address this challenge properly, as you're questions rightly pointed out. (total pixel resolution of the screen, view distance, etc)

I will have a meeting with the programmers of the screen rig and will have a clearer picture of the endeavor ahead...will post all the details soon.

 

[christopher witzke]

I've heard great things about the setup these folks have created....

http://www.mersive.com/About.html

 

[Craig Parkes]

I've done a setup where we finished to about 4K horizontally for a 25m wide by 4.5m high screen using 6 projectors - although that was animation mixed with live action, and the live action we shot HD because it was just a presenter/some dancers being keyed in.

The issue you'll face I imagine is not horizontal resolution, but one of framing. If you are shooting natively on the RED ONE for such a wide aspect ratio, if you are shooting 4K wide you'll only be able to show 682 pixels high from that scene so you are going to have to mask out almost all of your vertical space when shooting to get an idea of what will be projected, but in reality on screens that wide the audience generally can't physically look at everything at once so it's pretty difficult to frame subject matter for - traditional rules (rule of thirds etc) pretty much fly out the window.

In terms of resolution you are better to shoot 4.5K 4480x1920 as that will give you 746 pixels in height to play with.

If their final format delivery spec is much higher than 4480 x 746 pixels high you will probably have to consider shooting on two cameras side by side.

From my experiences though I would be surprised if it is significantly higher than that - but I guess it depends on the subject matter.

 

[Joao Miguel Luis]

Ok, I've got new details from the client. It's BIGGER! 10:1 ratio

Craig, It seems is actually very similar to your project. It is not a screen as I stated before, but rather a projection on a wall with 4,5 meters high (14.7 ft) and 45 meters long (147 ft) composed of 9 projectors working integrated. the projectors are 3 Chiped DLP, that produce a resolution of 1,470,000 (1,400 x 1,050) x 3, total of 4,410,000 pixels each.

The projection pane is at 3 meters from the ground and viewing point stars from 1 m to 30 meters...It's a permanent feature in a big space.

Subject matter would be almost like video postcards of breath taking places that can inflate a determined feel to the room itself. Little to none action...

Since i get 4K (real) per projector, would that mean I would have a total of 40k resolution, enough for my one RED set-up?

cheers

 

[alexx_hg]

You have to consider, that a projector works best at its native resolution, as soon as scaling is involved, it will introduce artifacts and noise. This takes you to the next question: What players or mediaservers will be used and what resolution will they get out. (i.e. doesn´t make sense to have 1440 projectors when the play out is only 1280) Next question is the overlap or softedgearea. Normally it works at around 20% of the horizontal pixels. From there you can calculate your pixels you need for each projector and what you have from your RED.

To my experience a 3:1 ratio works great without any compromise. We also have done a 7:1 panorama (one RED 4K2:1), but it was quite tricky and needs a well thought-out orchestration of your presentation.
As Craig already mentioned, try to get as much vertical pixels as possible. This will help you vastly especially for wide shots, this would mean 3 REDs would do best for your project and keep in mind that you have to render to a compressed format for the final stream for the players

BTW: Screen starting at 3m with 4,5m height, - distance from 1m doesn´t make any sense

bg
alex

 

[Michael Hastings]

Ok, I've got new details from the client. It's BIGGER! 10:1 ratio

Craig, It seems is actually very similar to your project. It is not a screen as I stated before, but rather a projection on a wall with 4,5 meters high (14.7 ft) and 45 meters long (147 ft) composed of 9 projectors working integrated. the projectors are 3 Chiped DLP, that produce a resolution of 1,470,000 (1,400 x 1,050) x 3, total of 4,410,000 pixels each.

The projection pane is at 3 meters from the ground and viewing point stars from 1 m to 30 meters...It's a permanent feature in a big space.

Subject matter would be almost like video postcards of breath taking places that can inflate a determined feel to the room itself. Little to none action...

Since i get 4K (real) per projector, would that mean I would have a total of 40k resolution, enough for my one RED set-up?

cheers

You don't have 4k for real - you don't count every pixel of every color.

Your projectors are 1400 RGB pixels wide - so you need 14000 pixels to work with, probably less since they presumably will overlap.

RED provides 4096 rgb pixels wide (figure about 3200 after debayer if you want to get absolute most sharpness) so 3 reds would give you 12000 pixels, 4 would give you 16000.

Biggest problem you will have is making a mount/holder for those cameras that is adjustable and solid enough. plus the 60 to 100 lbs of camera/lenses you will have to support.

 

[Stephen Gentle]

Ok, I've got new details from the client. It's BIGGER! 10:1 ratio

Craig, It seems is actually very similar to your project. It is not a screen as I stated before, but rather a projection on a wall with 4,5 meters high (14.7 ft) and 45 meters long (147 ft) composed of 9 projectors working integrated. the projectors are 3 Chiped DLP, that produce a resolution of 1,470,000 (1,400 x 1,050) x 3, total of 4,410,000 pixels each.

The projection pane is at 3 meters from the ground and viewing point stars from 1 m to 30 meters...It's a permanent feature in a big space.

Subject matter would be almost like video postcards of breath taking places that can inflate a determined feel to the room itself. Little to none action...

Since i get 4K (real) per projector, would that mean I would have a total of 40k resolution, enough for my one RED set-up?

cheers

I'm a bit confused about the dimensions. First of all, I think that you're mistaken about 4K per projector - they are only ~1.37K* at 4:3 resolution - the fact that they are three chip doesn't mean that you can multiply the resolution by 3, because the three colour channels are overlayed over each other.

Now, going by those resolutions I get that your aspect ratio is 12:1, but going by the measurements I get 10:1... If you only use eight projectors then you'd have 10.66:1, which is closer. So which is it?

OK, so I'll assume that you do have 10:1, where the vertical resolution is 1050 pixels. That makes your horizontal resolution 10500 pixels, which is 10.25K*. That's about two and a half times the resolution of RED ONE 4K, or 2.3 times the resolution of RED ONE 4.5K. So if you need to shoot an image that will take up the whole wall, what I'd do is shoot two RED ONEs side by side, and then you'd only have to upscale a little bit. That way, you'd be only throwing away half the vertical resolution, but if you shot one camera, you'd be throwing away more like 75%.

* I'm basing this on 1024, not 1000 pixels so it's directly comparable to 4K, which is 4 * 1024 pixels

 

[Joao Miguel Luis]

Your help is truly appreciated! All the questions you raise are totaly above my VERY LIMITED knowledge (sorry if I don't follow you in some issues and calculations.) and they will most certainly help me achieving the best result... for that I thank you guys.

I'm a bit confused about the dimensions. First of all, I think that you're mistaken about 4K per projector - they are only ~1.37K* at 4:3 resolution - the fact that they are three chip doesn't mean that you can multiply the resolution by 3, because the three colour channels are overlayed over each other.

Stephen, this is the projector in question and here's where I got that 4k pixel count. You can check the full spec here: http://www.panasonic.net/avc/projector/products/d12000/specifications.html#02

PT-D12000 DLP™ chip Panel size 0.95" diagonal (4:3 aspect ratio) Display method DLP™ chip x 3 (R, G, B), DLP™ projection system Pixels 1,470,000 (1,400 x 1,050) x 3, total of 4,410,000 pixels

BTW: Screen starting at 3m with 4,5m height, - distance from 1m doesn´t make any sense

Alexx,...what I tried to say is that the projection is something that is not the main attraction of the venue, but rather a mood setting feature, and people will be wondering around the venue, and they might be 1 meter away from the projection at a certain point, or 20 meters away...depends. I would think that you'll need to make the projection work at a determined point (maybe center of the venue), and compromise for the rest of the room.

Like I said, I'm way off my league here, trying to understand and master all this concepts, and I believe the people responsible for the projection know how to make the images work.

what concerns me as Director and Producer for this project is budgeting this correctly. I feel most of you agree on the fact that this cannot be done with only 1 RED camera, and so I will make a budget that supports 2 cameras.

About the shots themselves, any suggestions on the distance between cameras, lenses, ways to mount them together or any special recommendations? When you shoot with 2 cameras, do you overlap framing and how much is recommended? How is that overlap made in post?

once again,

many thanks

 

[Stephen Gentle]

Stephen, this is the projector in question and here's where I got that 4k pixel count. You can check the full spec here: http://www.panasonic.net/avc/projector/products/d12000/specifications.html#02

PT-D12000 DLP™ chip Panel size 0.95" diagonal (4:3 aspect ratio) Display method DLP™ chip x 3 (R, G, B), DLP™ projection system Pixels 1,470,000 (1,400 x 1,050) x 3, total of 4,410,000 pixels

That's how many pixels it has, but if you look four boxes down, you'll see that the actual resolution is just 1,400 by 1,050 pixels, which is 1.37K (the K number is the horizontal resolution (1400) divided by 1024. So RED ONE is 4096 pixels across, divided by 1024 = 4K).

 

[alexx_hg]

Like I said, I'm way off my league here, trying to understand and master all this concepts, and I believe the people responsible for the projection know how to make the images work.

forget the projector for the moment!

More important: ask the guys how they will play out your video, and what should be the framesize from your final video.
Than ask them if you can deliver a still image sequence in this needed pixelsize.
(Mostly done in AfterEffects i.e 10.000 x 720px)
There are different ways to split your video, the overlap normally is done by the software which the technicians are using.

If you know the framesize an the needed horizontal pixels go and do some tests.
For first and simple tests, just to get an idea, you can use stillphotograpy if you are not shure about lenses, distances, 2 or 3 cameras, etc.

It´s not an easy task what you want to do, and it needs testing and a close collaboration with the technicians.

good luck
bg
alex

 

[Joao Miguel Luis]

yep, that sounds like a plan. I'll post any pratical results and conclusions of this experience.

ty

 

[Roberto Lequeux]

Epic 617


Sounds like a fun project. Good luck.

 

[Craig Parkes]

Ok, I've got new details from the client. It's BIGGER! 10:1 ratio

Craig, It seems is actually very similar to your project. It is not a screen as I stated before, but rather a projection on a wall with 4,5 meters high (14.7 ft) and 45 meters long (147 ft) composed of 9 projectors working integrated. the projectors are 3 Chiped DLP, that produce a resolution of 1,470,000 (1,400 x 1,050) x 3, total of 4,410,000 pixels each.

The projection pane is at 3 meters from the ground and viewing point stars from 1 m to 30 meters...It's a permanent feature in a big space.

Subject matter would be almost like video postcards of breath taking places that can inflate a determined feel to the room itself. Little to none action...

Since i get 4K (real) per projector, would that mean I would have a total of 40k resolution, enough for my one RED set-up?
cheers

With a viewing distance of as close as 1 meter, without multiple cameras your footage is going to look pretty bad at that close range, especially your vertical resolution that would having to be upressed significantly (you'd be shooting about 450 pixels and upressing them to 1050 pixels, 450 pixels isn't a lot of information to start with, less than SD...)

With a 10:1 ratio and a height of 1050 pixels you will be getting 10500 pixels across. Upressing two RED ONE cameras at maximum recording width (4480)
is going to be your most practical choice. Also, You should be able to rent a side by side rig for two cameras relatively easily that will line up perfectly, because of the need for them in 3D. Comparatively you'll be upressing 896 vertical pixels to 1050 vertical pixels. That's not so terrible.

 

[Carlo Rho]

Last we shoot an ultra wide work for Spanish government, we covered 6 screens the biggest of something like 9000x1920px (9 HD projectors) for the Spanish house @ Expo Shanghai 2010, we did it with only 1 REDone.
The big deal is post-production.
You need to find the optical centre of every optic to be able to pan having vertical lines always parallel and not with the further ones passing from one side to the other of nearer as in a normal pan. (I think this concept it's a bit to complicate for my English)
If shooted in this way for post production is possible to connect your frames in a ultrawide aspect ratio.
We did it using just one camera and panning on a static tripod.
It's very complicated to explain all the procedure here but if you're interested you can contact me directly carlo@illcamaras.es
A static example of what we did for Expo Shanghai 2010, this is the Bilbao bridge, made merging 6 Redone clips, in video the lower part of the bridge is moving from one side to the other!