I couldn't figure out which category to post this, but I am using FCP so here we are.

What I am trying to do is record an interview over skype or ichat by basically having our host have a conversation with the guest which we will record in studio, but I also want to screen capture the guest's video feed so that I don't have to point a camera at the screen! The only thing is that when I capture it (using ishowu HD) it has a lot of lag.

I am guessing this is a frame rate thing, but can't figure out what settings to use to make it look good. I am going to basically try everything, but thought I would see if anyone here has tried this already and knows how to make it work the best. Thanks!

There's only 2 programs I can think of that can pull this off well:

Either Screenium:

Synium (http://www.synium.de/products/screenium/index.html)

or Snapz Pro X:

Snapz Pro X | Ambrosia Software, Inc. (http://www.ambrosiasw.com/utilities/snapzprox/)

I do this kind of stuff all the time and have found that *any* software will bog down the system for screen capture.

If you can invest in it, the Matrox MXO 1 is the best option.
It allows you to send your desktop screen to another capture card via HD-SDI / SDI and Component HD, allowing you to capture real-time without the hiccups of software.
Audio is sent Analog from your headphone output.

The flip side is you need the MXO 1 and another capture card (AJA, BlackMagic, ect) and of course two computers running Host/Record.

-C

Chris D is right: Any software-based screen-capture app is going to slow down refresh rates when loaded on the same system, but the two apps I recommended have the least amount of overhead and the highest frame-rates possible for the operation you want.

iShowU HD is what I've used for a while now and it doesn't seem to bog at all.

I have a lot of success using Screenflow, but don't know what sort of overhead/problems it might cause in this specific situation.

Screencasting Software - ScreenFlow Overview - Telestream (http://www.telestream.net/screen-flow/overview.htm)

Thanks for all the replies guys. I am going to explore all of these options, starting with the cheapest ;)

Robert, Ishowu HD is what we have, what are your settings for this? If I can get it to work, even if I have to tell them not to MOVE, that would be great!

I change it quite often due to different client requirements. So no one setting has proven better than the others. I usually use Apple intermediate codec or animation codec. I also capture 30fps with sound and mouse movements. One thing that does matter is the speed of your computer. I'm on an 8-core 2.66 macpro. If you're on a slower computer, you might have to drop the frame rate a bit if it starts bogging. Just looked at my last settings and I captured 3840x2400 30fps AIC. Allows me to scale in FCP or AE without losing resolution.
Hope this helps!

ok that makes sense, I have been trying it on a macbook pro. My Mac Pro is in a different building from the studio, so now I will have to be really creative to make this work. I will try lowering the frame rate.