[ANSWERED] Capture stage
At the very moment my first theatre play with live projection (with Isadora, of course) is running. I've been working on it for months, in march 2020 it has been postponed due to Covid-19 - but 'never waste a good crisis', so the last year I invested in camera's, and, more important, how all that technical stuff works. 2 years ago I knew nothing about all this stuff, exact one year ago I bought my first camera (a black magic pocket cinema camera 4, BMPCC4k), fell in some kind of rabbit hole of camera-gear, and like I said: at the moment my very first play with live projection is begin performed. I'm using two BMPCC4k's and a Panasonic Lumix G7, all 3 connected to an Atem Mini Pro Iso, so I can easily switch camera during the show.
So, it's all very new to me, but very exciting, and I'm getting very good responses.
Thanks to the Atem Mini Pro Iso it's also very easy to record the show, but at the moment I'm trying to find out how to record the stage from Isadora - so I can mix it afterwards.
I thought that would be 'the easy part' because there's an option to 'record the stage output', but I already noticed that this can't be used to just record the hole play (= 120 minutes).
So at the moment I'm having a 'capture stage to disc'-actor in some scenes and the last week I've been experimenting with it, but I'm struggling to understand the limitations of this. And since the play will only be performed for 3 more times (today, tomorrow, the day after tomorrow), I'm running low on time. (And I'm a little reluctant to experiment a lot during the show.)
As far as I understand the 'capture stage to disc'-actor:
- It should be no problem to start capture the stage, and go to the next scene while this is going on
- but there seems to be a limitation on 'time': I can capture the stage for a few minutes, but when it's going on for a longer period, problems arise.
Does anyone know what the maximum amount of time is you can capture? And any suggestions on how to measure this without having to hold a stopwatch in my hand? Is there a way to start a clock when the capture starts?
Any other suggestion or advise on capturing the stage is welcome.
mark_m last edited by
Do you have a spare HDMI port on your computer? Since you're only using three cameras you must have a spare input in the ATEM Mini ISO. If you do, then you could attach the HDMI output to the ATEM. Isadora will recognise it as another display You can add a stage to that display. Duplicate your projector(s) in each Isadora scene and change to the stage which is going out to the ATEM Mini, which can now record the stage to one of its ISO streams.
Mark (a different one)
Thank you very much for this suggestion.
I do not have a second hdmi-outpot on my laptop, but: maybe I could use a hdmi-splitter, and sending one hdmi-signal to the projector and one hdmi-signal to the atem;
without having to do anything in Isadora, the Atem would record the 'stage 1'-output that's also going to my projector.
I do not have a hdmi-splitter, but I'm passing by a shop that might sell one, so If they have one, I might find out within 3 hours if this works :)
mark_m last edited by
You could use an HDMI splitter - which probably is the easiest way to do this - but looking at the specs of your laptop two of the USB-C outputs - the one on the left side and the one on the rear - are DisplayPort compliant, so you just need a USB-C to HDMI cable to attach one of them to the ATEM Mini ISO, or, indeed to more projectors for future projects.
I bought a hdmi-splitter and tried it yesterday: one signal to the projector, the other to the Atem, and it worked perfectly. So, I'm verry happy with it, thanks again. I seems simple now, but for some reason I didn't think of the option to put the hdmi-signal of the laptop in the Atem again. (It reminds me of the snake that eats his own tail: because now I could use the hdmi-signal from the laptop to the atem also as the input from the Atem to the laptop.)
The USB-C to HDMI option would probably work too, but I don't have a usb-c to hdmi-cable either, so I would had to buy it also. But: I didn't think of it before, and this opens a world of options for future projects - because I was indeed thinking that I could only use one projector because I have only one hdmi-out slot.
I bought a hdmi-splitter and tried it yesterday: one signal to the projector, the other to the Atem, and it worked perfectly
Another reason this is a better option is that it means the work required to record everything is offloaded from the show computer to another device, so it ensures your show computer isn't spreading itself too thin.
When I want to take production stills from a live feed or record my output, I use the splitter method and then do the recording on a second computer (sometimes with a second Isadora patch that gets triggered to start/stop recording or capture a still image to disk based on OSC triggers).