Multi-Image in 2020

[perkeleellinen]

I am influenced by Michael Firstlight's post here. Multi-image is a term used to describe a forgotten photographic industry supporting multiple projection and sound presentations. As the industry progressed in the 1980s some very complex slide shows became possible using often more than 50 projectors operating at maybe 6fps and synced to a music score. There are great examples on youtube.

I want to see how far this forgotten craft can be resurrected in 2020. Here's my rig:


The Ektapro 9010 is a great projector and when coupled like this it can dissolve anywhere from a hard cut to ten seconds, it can support parallel projection, switching between projectors without forwarding the slides and fully automatic, continuous projection. However, it cannot support for example ten slide dissolves followed by parallel projection followed by hard cuts. For that I need a machine that can command the projectors.

Here is where I am now thinking. Back in the 1970s and 1980s there was an industry that supported all these complex projector commands and more but that has now all gone. Each firm had developed a different language to talk to projectors through audio pulses. The good thing about the Ektachrome 9010s is that they support Kodak's language P-COM and literature from the 1990s says they can connect to a computer using an RS232 cable. If I could get my laptop to talk to my projectors I think I could do what I want with multi-image. However, there is nothing at all online about this. If I can get this to work I will buy a third projector and try and create something exciting...

Some questions:

1. is it possible to connect a projector to a laptop using a RS232 output and a USB input?
2. Is there any software that supports this in 2020?
   
3. Am I the only person in the world working this way in 2020?

Thanks!

 

[Donald Qualls]

USB to serial adapters are available, and most slightly older laptops will actually have an RS-232 serial port on the back (DB-9, usually, though a few might have DB-25 with most of the pins vacant on the inside). If your laptop has a PCMCIA port, there were also RS-232 adapters for that interface.

Windows 10 and any current version of Linux still support serial ports, because there are still devices in fairly common use that use them (like external modems for low-rate DSL or 56k and slower phone line modems). Can't say for sure about Mac, but I'd be mildly surprised; Apple hasn't put a serial port on a Mac in ten years or more, and they've had several significant OS upgrades since then.

I think you could convince PowerPoint or OpenOffice Impress to output a recorded audio tone with each slide change, so your on-screen display could be synchronized with what the projectors are doing. I don't think the RS-232 connection will run on audio tones, though, so you might be stuck looking for a DOS-based control program that you can run in a virtual machine (or install an actual DOS on the bare metal, but that's doing it the hard way as well as leading to issues with even current versions like FreeDOS recognizing modern hardware).

You might well be the only person still trying to do PowerPoint with film projection, but the first time you mentioned this, I immediately thought of the "Beloved Leader" multimedia slow in Sleeper (Woody Allen, Diane Keaton). Fades, different screen splits, even motion, all perfectly synchronized with the audio as the camera cut back and forth between the screen and Woody's face.

 

[perkeleellinen]

Thanks, Donald, much food for thought for sure.

I went back to the Ektapro instruction manual and it says that P-COM language transfers as binary code to the projector. In the P-COM manual it confusingly states that no software is needed and direct communication is possible. Perhaps with early '90s computers it was possible to open a terminal and type commands directly to the projector via the 232 cable. In any event, that is not where I want to be as that is real-time programming and I want to be able to program a show and then load it so I can watch it.

Early dissolve units from the '80s had no way to store commands so those huge shows must have been crazy work for the dissolve operators! Those units also were designed for Carousels with DIN connectors and the later Ektapros are not compatible. By the early '90s when the Ektapros were made a number of the Multi-Image firms like AVL had exited the market.

A bit of digging and I think there are some potential dissolve machines:

Arion Show Wizard - runs through a USB, is Ektapro compatible and has software supplied on a CD. Negative is the high costs; probably $1000+ and I can't see any on ebay
Dataton Smart PAX - Ektapro compatible, uses TRAX software which maybe Macintosh only and was supplied on 3.5" floppies! Lots on ebay
Stumpfl SD 402 - Ektapro compatible, software on CD, used units turn up on ebay, however, the software and instructions are German only.

These might be the only three firms that made Ektapro compatible machines.

The Ektapro instruction manual mentions software available to control the projectors without the need for a dissolve unit; it suggests contacting your local Kodak dealer for names and addresses! I can't find any reference online to software for this. Weird how little is written (and now known) about this topic.

 

[ChristopherCoy]

I have nothing to add here, but thank you for this post! This will be the most interesting thing I watch all day. I had no idea these things existed.

 

[perkeleellinen]

That video is what's making me pursue this! Only three projectors!!

 

[ic-racer]

If I were doing that I'd probably use something like this (Arduino RS232 driver): https://www.arduino.cc/en/Tutorial/ArduinoSoftwareRS232

Looks like there is enough info in this document to program the Arduino to control the projectors.

https://resources.kodak.com/support/pdf/en/manuals/slideProj/ektapro_PcomProtocol.pdf

 

[Donald Qualls]

Good thing with Arduino is you can buy it with the RS-232 already installed on the board (I think), unlike, say, a Raspberry Pi (descendant) that will be all USB, all the time. But if you put Ubuntu on an old, obsolete laptop (say, 10-15 years old), it'll run okay and you can write scripts in Python to output commands to RS-232. Python comes preinstalled, and is easy to learn -- works quite a bit like BASIC, only it's modern.

 

[perkeleellinen]

Arduino would be a learning curve for sure. I have a background in programming from a previous life working in the automotive industry where I programmed measuring machines using an Unix derived language so it wouldn't be a complete cold start.

I also emailed Stumpfl in Austria asking if the SD 402 could talk to a Windows 10 machine. Not confident they will respond as I'm sure their helpdesk staff are digital natives who won't have a clue what I'm talking about!

 

[perkeleellinen]

Bought a third Ektapro so I'm committed now.



I've decided not to bother with all these third party dissolve commanders from the 1990s, getting them to work on modern machines will be too much of a headache. What I want from these is fairly simple so I'm going to try commanding directly from my laptop with Windows 10 or a Linux machine through a Terminal program like cutecom or comport. First job is a usb-RS232 cable and driver.

 

[perkeleellinen]

Update. I've daisy chained three Ektapros and I'm controlling them using a neat piece of software called Ektaprogiu on my laptop. Some success:



The problem (headache) I'm having now is that the middle projector won't communicate. But as you can see the other two are so the daisy chain must be working (bottom is command, other two are slaves). I've tried changing the address switch at the back to different positions but it doesn't help. I also don't know why they're projecting in parallel, I'm aiming for a three projector dissolve.

 

[perkeleellinen]

Hmm, I think my issue is the address switches. I remembered that the top projector (5020) has no P-Bus out so must be at the end of a daisy chain and because it has no address switch it is allocated '0'. Problem was the bottom projector (9010) was also set to '0'! (explains the parallel projection). I moved the bottom to '1', middle to '2' and the top is '0'. This had the effect of the laptop only communicating with the top projector! I think this confirms I need to work on the addresses to get proper communication.

Now back to my day job!

 

[Chan Tran]

I haven't done software programming with modern flatform but I think I can write a program in Visual Basic to control the projector.

 

[perkeleellinen]

That's interesting, I am wondering if I could too. I have a background in programming (but 20 years ago) so I understand the logic and grammar but not the language of modern programming. EktaproGUI is written in Python. The Kodak P-COM protocol is quite simple but I'm having trouble seeing P-COM within the Python programme. I think it's because I don;t know what to look for.

So, I fiddled a bit more with these machines:

• All three work as stand alone projectors commanded by my laptop if the address is '0'
  
• If I add a second projector addressed as '0' I get parallel projection
  
• If I change the addresses the software only communicates with the '0' projector
  
• Addresses go from 0-9 and A-F, I've only tried '0', '1' and '2' so far.

 

[perkeleellinen]

I opened the programme in a text editor and noticed this at the start:

"Currently, only one projector per serial port is supported"

Does this mean my daisy chaining will never work as the programme can only recognise a single projector per port? I do I then need something like this 4 port USB converter? Expensive, cable so I want to make sure before I buy.

 

[Donald Qualls]

Sounds like it -- that or a couple $10 dual serial cards (if you have enough slots and backplane spaces for them).

Edit: 'Doh! Forgot, you're on a laptop. You should be able to use a $15 4-port USB hub; each port gets its own address.

 

[perkeleellinen]

$15 4-port USB hub; each port gets its own address.

With three MAX232 - USB cables?

 

[Donald Qualls]

Ugh. Do they have to be MAX232? I've seen USB to D-9 or D-25 serial for $5 to $10 each.

 

[perkeleellinen]

Unsure, all I do know is that the MAX232 I've got here works and the laptop can command the projector. I'm tempted to get the more expensive cable as it's a known good, I've got a history of buying the cheaper option only to end up buying the more expensive one later!

 

[perkeleellinen]

I'm getting there!



Just got to tease that bottom machine to play along...

 

[Chan Tran]

That's interesting, I am wondering if I could too. I have a background in programming (but 20 years ago) so I understand the logic and grammar but not the language of modern programming. EktaproGUI is written in Python. The Kodak P-COM protocol is quite simple but I'm having trouble seeing P-COM within the Python programme. I think it's because I don;t know what to look for.

So, I fiddled a bit more with these machines:

• All three work as stand alone projectors commanded by my laptop if the address is '0'
  
• If I add a second projector addressed as '0' I get parallel projection
  
• If I change the addresses the software only communicates with the '0' projector
  
• Addresses go from 0-9 and A-F, I've only tried '0', '1' and '2' so far.

Is there a setting in the software for which address? If not I think the software uses only address 0.

 

[koraks]

I opened the programme in a text editor and noticed this at the start:

"Currently, only one projector per serial port is supported"

Does this mean my daisy chaining will never work as the programme can only recognise a single projector per port? I do I then need something like this 4 port USB converter? Expensive, cable so I want to make sure before I buy.

Daisy chaining should work in principle. Looks like the protocol is pretty simple, so it should be fairly straightforward to modify the software to allow addressing multiple projectors - or simply start over and make some new code.

 

[perkeleellinen]

I bought the MAX232 cables and I'm happy to report that the software now recognises two projectors and commands them as you can see in the above video. Unsure why the bottom projector is unresponsive, even when I plug that one direct into my laptop. Weird because that one was working when I connected them on a daisy chain. Going to switch round some cables and check connections tomorrow.

I can conform the software only recognises address '0'.

Once I'm confident that I can get all three of these machines synced then I want to try and adapt the program to add a few more commands. I've seen people adapt it to work on Raspberry Pi and Arduino with a screen connected. Long term aim is to create a show involving three full carousels (240 slides) of stop-motion skateboarding with a music track.

 

[Chan Tran]

I bought the MAX232 cables and I'm happy to report that the software now recognises two projectors and commands them as you can see in the above video. Unsure why the bottom projector is unresponsive, even when I plug that one direct into my laptop. Going to switch round some cables and check connections tomorrow.

I can conform the software only recognises address '0'.

Once I'm confident that I can get all three of these machines synced then I want to try and adapt the program to add a few more commands. I've seen people adapt it to work on Raspberry Pi and Arduino with a screen connected. Long term aim is to create a show involving three full carousels (240 slides) of stop-motion skateboarding with a music track.

Since most Python software come with source code perhaps you can modify it to accept different address. Your post make me want at least a couple of the Ektapro but they are too expensive.

 

[perkeleellinen]

I think because they're German made they are more common in Europe than the US, although not cheap, they do turn up frequently on ebay. I'm lucky that I got my two 9010s free when an AV room at a local institution was cleared out. I saved them from the dumpster!

Great if you bought some, Chan, then we could work on a program together, I work much better in a team.

 

[AgX]

Surprisingly I never came across an Ektapro locally and only 3 german Carousels.