Black level on key


I am using CasparCG with a decklink 4k extreme feeding into an Atem mixer.

I'm finding that the key output isn't black even with no graphics present.

Is there an adjustment I can make on either of those devices to resolve this?


Re: Black level on key

Thanks Didi for your quick reply.

My Atem is configured as suggested, gain is disabled once pre-multiplied is selected.
The problem is the Key output is something like 95% black so I see a drop in video levels once the key is in circuit.

Re: Black level on key

Decklink control panel looks okay to me (is there a list of recommended settings?)

I have two cards in the same machine and they both behave the same.

Is there a recommended driver version for use with CasparCG?

Re: Black level on key

Experienced the same issue. Downgrading the drivers solved it as suggested. Thanks to the op and pin down.
CCG_1: Rack Z420, Xeon E5, 16GB ECC, Intel OS SSD + Media/Temps @ Striped Sandisk 480 GB SSD's, 4K Extreme + QUAD, Quadro K2200, Juli@ Audio,
    CCG_2: Rack, Core i7-6700K, 32GB DDR4, OS @ M.2 Intel, Media/Temps @ M.2 960 PRO 2TB, 4K Extreme, GTX 1080