Preliminary advice on a new Isadora system spec



  • Hey All,

    Our theatre company here in Calgary, AB, CA (Theatre Junction) is in the early stages of creating a new piece with some ambitious video requirements (at least for us, thus far).  The short story is we want to achieve seamless Isadora coverage of a 65' long by 18' high curved cyclorama.  Imagine a semi circle with an elongated middle section.
    We have some experience with izzy and have seem many companies come through doing similar wrap around projections (Architecting from TEAM NYC being the most direct example).  Our current plan is to work with 3 projectors rigged as far upstage as possible (to avoid shadowing from set pieces) and a Matrox TH2G to split the single output of a Mac Pro across the three.  We're fairly confident that this is the way for us to go but have 3 main questions:
    1\.  What (if any) specs do we need to watch out for when buying a new Mac Pro to serve as our video system.  Are there any specific things we want to watch out for or upgrade to vs. the current base model?  Obviously the most loaded machine is ideal but in an effort to not over spend we are wondering which features are most important (i.e. how many CPUs, how much ram, video card specs).  Lastly on this subject can anyone comment on the advantage of working with multiple video cards within the one tower vs. splitting a single output with the TH2G?
    2\.  Our plan is to reach our projectors over Cat5e cable using either DVI or VGA baluns (we currently have a DVI TH2G and won't buy another VGA version if we don't need to).  Is there a specific DVI balun that you guys are using and what are the considerations there?  Does using baluns vs. straight cable runs introduce extra latency concerns?  Is there a reason we should be investing in a VGA version of the TH2G or will our DVI version work just as well?
    3\.  We will be working with live video of up to four sources.  What recommendations/products are you guys using with a Mac Pro to achieve this?  We would only need to work with standard definition (composite) video resolution/inputs but would need to access all 4 simultaneously with independent control in the software.  Ideally this solution would be an internal card we can install in the Mac Pro vs. an external unit and would have the lowest possible latency without shooting our budget into outer space.  It is a large concern to reduce latency of the live video/projection as the real time actions are in view of the audience at the same time as the projected video.  We have some considerable monies to invest in this control system but it's not unlimited.
    Thanks much for your time and insights here.  We want to make the right decision on the control system we chose as our company will continue to work with video in increasing amounts as we make new work in the future.  Our hope is that we include as much touring as possible with our new work, and are mindful of building our shows suitable for touring.
    Cheers,
    Phil S. Cimolai
    Head Sound Technician
    Theatre Junction Company


  • Hi Phil,

    1\. There was an article somewhere that showed that there is minimal advantages with Isadora for a second CPU so I would look at getting a top speced single 6-core processor. I would shoot for 8-16GB worth of RAM. For a Mac Pro you are better off getting extra RAM and HDs from a company like OWC and installing them yourself instead of paying Apple to do it. You are probably going to want the dual Radeon 5770 graphic cards. There is absolutely no advantage to using a TH2G for this and, in fact, there is a significant disadvantage since you will be forcing one GPU to pick up all the processing instead of splitting it across a pair of graphics cards. I would also strongly you are also going to be pushing a lot of pixels off of your drives so I would seriously look at picking up a small SSD (60-120GB) as you boot drive and then doing a RAIDed pair of larger ones (256-512GB) for the media drives. This won't cost that much in the scheme of the whole machine and will be a big performance boost. SSDs are also more reliable for when you want to tour it since there are no moving parts.
    2\. If you are looking at getting more budget conscious baluns then you should stick with VGA units and I would recommend Gefen's more affordable units for that purpose. My general preference is DVI over Fibre but if that is too expensive then I have had good luck with the Gefen DVI Extra Long Range Extender (EXT-DVI-ELR) and the Gefen DVI Over 1 CAT6 unit (EXT-DVI-1CAT6). Baluns/extenders should not have an effect on latency.
    3\. I think your only viable option for this is the Active Silicon LFG4\. Mark has used these and I know of several others who have as well. Your looking at something like $800-900 for one of those but it will do exactly what you need I can't think of anything else that can.
    Are you planning to perform geometric compensation in Isadora or are you going to be doing all of that in advance and then burning it into the finished files? Either way, there is nothing about this that is particularly ambitious in the sceme of what Isadora has been used for and it sounds like you have enough budget to do it right so I wouldn't worry.


  • My advice coming from my experience is to hire local experts to develop the system - projectors, cables, hardware needed. Usually projector rentals/sales companies have good knowledge about these things. Then you can concentrate on developing the show and not having to deal with hardware failures that take all your time and energy.



  • Thanks for the great response Mathew. I've been speaking with a video specialist who we intend to hire to work on our show with us who commended basically the same things as you. I have one question in response: We've been looking at a capture card from black magic devices vs. the AS product you recommend. It's the Decklink Quad pci card. Any experience with this or thoughts there? Thanks very much.



  • I haven't heard any reports of Isadora users working with the BM product so unless someone chimes in with their experiences you would probably be better off sticking with the proven AS unit.



  • Hi,

    The decklink quad capture sdi signal but not composite.
    If you want to capture 4 composite feeds the lfg4 is a good solution.
    Viewcast also have a solution to capture 4 composite feeds but only for windows machines.
    Best
    Mehdi

  • Tech Staff

    I've used the DeckLink quad. Running 3 and 4 SDI inputs. Used external analogie to SDI converters from analogue cameras. Worked well on a reasonably well spec machine (mac)



  • Although I agree with Matthew that separate video cards is preferred over the TH2Go, the triple head DVI does output VGA if you buy the inexpensive DVI-VGA adapters.  (On the other hand, the display port and mini display port versions do not output VGA and the D to A conversion has to be done externally).

    I disagree, however, with Vanakaru.  I have found most often that equipment sales companies cannot wrap their heads around the "complex" stuff we are doing with projectors and are stuck on the idea of projecting onto flat surfaces.  They are a valuable resource, but make sure you double check all the specs before committing to any piece of equipment (e.g. can the projector be tipped down or off-axis or will the built in edge blending work on a curved surface). 


  • @CraigAlfredson

    I may be spoiled here in Estonia. We work with projector rentals always specially if we have a complex project. Most often it is an opportunity for them to try(also purchase) new hardware and I think we get better price than everyday boring customers.


  • I always prefer TripleHead2Go to a graphics card dedicated to a performance. Why? Imagine, you find out your computer died 1 hour before the show. With TripleHead2Go it is easier to put a replacement in place.

    --8


  • CraigAlfredson: I'm a little confused about your Mini DisplayPort > VGA comment. Can you not simply use Mini DisplayPort to VGA adapter cables that are sold from many including apple? It's clear I need to do some more research into The SDI format since I'm not wholely clear on it. Perhaps I need to think for a different card than the BMD Decklink. Thanks all for the comments. I'm going to post my planned spec here in hopes of any further feedback soon. Best, Phil



  • pcimolai: While you can just use a MiniDP>VGA adapter with the graphics card, the DisplayPort version of the TH2G that CraigAlfredson was referring to is more picky about the kind of adapters it requires. 

    eight: You make a valid point although, in my experience, finding a suitably powerful computer to drop in as a replacement for a $4k Mac Pro lying around a theatre at 1 hour to curtain is pretty much impossible. In general, the run crew also does not posses the knowledge to make such a swap anyway and by that point in the process, I've long moved on to another production. If the producers can't afford to have a show without projection then they need to pay for a system with redundant playback machines.

  • Tech Staff

    @CraigAlfredson @vanakaru

    I must agree with CraigAlfredson, here in Switzerland it is difficult to find an equipment sales company that has the knowledge we need. Most of the time they can't answer quite basic questions of what the product they sell can do or not.

    Best,
    Michel



  • @MatthewH:

    In that specific case the production computer was an about $2000 hackintosh, there was also a spare $1000 hackintosh, less capable but still acceptable, and the running crew was prepared and willing to do the computer swap (which they never had to). I myself developed on Macbook pro, pluggable into 3h2go at will. Since then I am a strong advocate of 3h2gos, which allow to easily put a venue computer behind them, once my MBP development is done and leaves the venue with some inexpensive options, once I am gone.
    --8


  • I suppose I should clarify my comments about Matrox dual and triple heads.  I use them extensively and think they are a great piece of equipment to get two or three outputs out of a single laptop.  For most shows that are not too heavy on the graphics processing they work fine, but they are no substitute for a Mac Pro with discreet graphics cards.

    What I meant with my comment about the display port versions is that they do not do digital to analog conversion.  Even the new "Mac Edition" that outputs DVI does not support analog; i.e. you cannot simply put the cheap DVI to VGA adapters on the end and output to VGA.  You can use the display port editions with external Displayport to VGA adapters, but these adapters are no easy to come by and have a tendency to break (2 out of 4 that I have used have stopped working unexpectedly). You are also relying on a ~$40 part to do your digital to analog conversion, which isn't necessarily a good idea.
    You can use one of the analog editions with a standard mini display port to VGA adapter, but again you are relying on an adapter to do your DA conversion and they are prone to breaking.  At least the MDP to VGA adapters are easy to find at your local Apple store or Best Buy.
    The best solution from Matrox is the Triple Head 2 Go Digital Edition.  You can input DVI (via the passive MDP to DVI adapter) and output either DVI (digital) or VGA (analog) via passive adapters.  That way the Matrox is doing the DA conversion for you.  That is also why it is the most expensive of the lot.


  • Hi,
    unfortunately that last post came after i purchased my TH2Go, Digital SE...
    My point was (except the price) to go at the simplest connexion : direct MiniDP to DP, cable included with the box...

    1. it does not convert digital to analog as said below, and as the info was not so clear (at least for me) on Matrox website (means they don't say it works, either it does not...) i did ask advices to some reseller that said it will... (@Vanaraku)
    2. Even if it is sold as Mac compatible, you can't find the proper driver to run it, i did have to say i had a Digital (not SE) Matrox to find it, and i can't check if it's a complete version, running properly (it's my 1st TH2Go... does anybody knows??).
    3. i'm actually fighting with the reseller to exchange it with a Digital (all DVI) one, to connect my projectors in VGA, but it's not done, so in case of i have to deal with this TH2Go Digital SE, and because i'm in a low budget production, i thought about connect in HDMI (i'm close to the projectors, around 20 meters, and can have those cables available), with simple adapters DVI-D/HDMI.
      Do you think it would work?
      With a MBP, in Snow Leopard, and that "not so adapted" driver??

    Thanx



  • Sorry, it was Maïa (France)



  • this is  in attached file what i have as driver (some functions are closed cause i did connect only one monitor, but here is the interface).
    Is it this?
    Thanx again, Maïa

    9af5be-matrox-driver.jpg


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