I can't figure how to keep Live View on with an external monitor attached, anyone?

There is a Live View timeout setting in the camera's menu system.

I believe live view is disabled if an HDMI cable is connected to the camera.

Cheers, was using the a/v cable out to a HD monitor, and had liveView timeout set to never; maybe I need an HDMI to component or SDI conversion cable as my monitor has no HDMI.

so unless you are using the hdmi out, the lcd will timeout if you are using the AV out?

To be clear - I'm wanting to know how to keep an external monitor constantly on during shot set up and shooting - do more experienced users advise that this can only be achieved with an hdmi-connected monitor, and the LiveView set to Never?

http://www.dvinfo.net/forum/canon-eos-rebel-t2i-eos-550d-hd/474389-does-work-550d-t2i.html

Check this out...here's your solution. Use a laptop with the Canon software to get the live view on both your camera and computer. All you need is a long usb cord or an extension for the provided one!

The whole camera can be controlled from the computer, including the aperture/iso/shutter and auto focus! really cool!

Cheers Robert - the laptop monitor solution will be great indoors, but I'm thinking more about use outdoors, solo shooting, where having the laptop won't be so practical (have MacBook Pro 15" - too big). And need to monitor externally eg if camera is at ground level or above my height on a tripod.

Just been through the menus again - there is no setting to disable the LiveView switching-off, only a setting to stop the LCD switch-off when your eye nears the viewfinder.

So it'd be great if anyone can confirm if the HDMI monitor solution leaves the picture always on, or if it continues to switch off after x seconds, like the composite output.

As mentioned above. I believe the cameras lcd output is disabled as soon as an HDMI cable is connected.

Colin is correct as I have tried it with my SmallHD DP1 via hdmi.

Understand the LCD goes off - but does the HDMI monitor stay on or keep getting switched off by the camera like the liveview on the lcd?

no, it stays on.

Just to open up another can of worms for you, you mentioned you wanted to use an lcd outdoors?
Unless you have a hood and a pretty bright monitor, it's not going to be what you expect. I suppose you could use it for framing. Also, if you are planning to use it for focus, keep in mind that the hdmi out shows 1080 until you hit record then switches to 480 which isn't that great. I was hoping to use my DP1 with the T2i but it just isn't ideal, so I use the monitor with my Panasonic which helps that camera a lot!
Since I shoot a LOT outdoors here in AZ, I have purchased a Zacuto Z-finder (though there are plenty of cheaper options) This gives me a MUCH better view for focus and works flawlessly in sunlight. Though if I had to mount the camera high up or on a jib, it wouldn't work.

These DSLR's are great for some stuff but terrible for others. That's why I will always have a camcorder in my rig.

Cheers Robert, we have a Panasonic 9in BTLH-80W HD-SDI monitor that we use with our Ex1 / Letus, but it doesn't have HDMI in, "just" SDI and component - I'll try a HDMI > component cable and report back.