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Lower Thirds w/Propresenter

PostPosted: Mon Mar 05, 2018 6:42 pm
by MICHAEL CULP
I'm running Propresenter version 6.3.3 and ATEM Production Studio 4k with ATEM Software Control (both version 7.2).

I am interested in running lower third slides from propresenter and overlaying them on top of live video through blackmagic. Right now, I can only get it to work by running my media source through downstream key as both fill source and key source. This allows me to display text but any other graphics I put on the slide does not show or is keyed out.

I'd like to know how to do this the right way that also gives me the ability to display lower thirds graphics, logos, etc.

Any help would be appreciated. Thanks!

Re: Lower Thirds w/Propresenter

PostPosted: Tue Mar 06, 2018 6:20 pm
by Scott Smith
Propresenter has an SDI module for sale as well as a alpha channel module for sale as add on licenses to Propresenter. The most professional and appropriate way to key your graphics is to use an alpha channel. Alpha channels cut the hole, and the fill video fills the hole. So, the hole and fill are always exactly what you want it to be (or at least what you set them to be).

So to do this "right", you'd want to buy those two licenses, and (if you don't already have it) a compatible Decklink product. Then you would run two separate SDI cables to the ATEM, one for the key and one for the fill, and set up the downstream key to have those as your key and fill sources.

One of the great things about key channels (alpha channels) is that you can make semi-transparency through making the key channel not white, but shades of gray.

Modules: https://renewedvision.com/propresenter/modules/
Supported Products: https://support.renewedvision.com/artic ... ic-devices

Re: Lower Thirds w/Propresenter

PostPosted: Tue Mar 06, 2018 6:24 pm
by Scott Smith
All of that said, there are ways of setting up your lower third and linear keying it (or even chroma keying it) so that you get a decent result. But you have to give up some things. So for a linear key, you would make the background black with your lower third at the bottom, but make sure not to use black in your lower third graphics. Similarly, you could chroma key it with any color - say green - and not have that color anywhere in your graphics. These aren't perfect. But they mostly work fine with proper planning and attention to the limitations.

When I say "no black", that often can mean that you use a super-black (0%) for the background and can do a dark gray successfully (maybe 20%), and have that look black'ish.

Re: Lower Thirds w/Propresenter

PostPosted: Tue Mar 06, 2018 8:23 pm
by Scott Smith
An example of good alpha channel usage with solid graphics to make semi-transparency:
The lower 3rd:
Image
The Alpha channel:
Image
The result:
Image
Notice you can see through the L3 at the right where the alpha channel turns black, AND that it remains the green color with no bleeding of the black background into it. The black text is also opaque. You can't really do this without a proper alpha channel.

This is done with targa files. Similar can be done with PNG files, but you don't have the actual alpha channel to work with, as it is a kind of embedded alpha channel. PNG's essentially use transparency instead a true alpha. Sort of. But they work.

I am honestly unsure about how to utilize alpha channels properly within Propresenter. It is an option I have considered getting many times, but since we have a real CG, we haven't done it. You will have to look that up. I am not sure if it will create them for you, as a good Character Generator system will. I doubt it. Most likely, you will have to create graphics with alpha channels in some fashion similar to the above. I am also unsure if it will turn PNG transparency into an alpha channel key signal on that second cable. It might, might not.

Re: Lower Thirds w/Propresenter

PostPosted: Thu Jun 21, 2018 9:10 pm
by dougduggins
Michael, I am about to try the same thing you are trying to do. Have you had any success in key out the lower thirds without buying the Alpha Keyer Module? I was hoping that if you turned the key button off on the software switcher when you want to display a full screen image would work. I probably don't have a clue what I am talking about but I would love to know how to do this without spending over $1000.

Re: Lower Thirds w/Propresenter

PostPosted: Sat Jun 23, 2018 12:13 pm
by Thomas Seewald
You can‘t create good semitransparencies without a dedicated key signal. You can do a workable key, when using luma key, white fonts and a light background box. You also may try to use the fill signal also as key. Explore the different settings ! I‘m sure, you will find a setting with works done for you without having a real key signal.

Re: Lower Thirds w/Propresenter

PostPosted: Tue Jun 26, 2018 10:55 pm
by Evan Vickers
If you are fine with static keys, you could do what I did. I have an image in the media pool that is my alpha style signal (black background, white box) and use that as the key source in the DSK/USK. Then the graphics from ProPresenter that are in that area are the fill. It's pretty simple, and if you want you can do alot with variations in the key graphic. You could even load a short video clip into the media pool as a loop and use that for the key.