Question / Help Recent webcam lag where working previously fine


New Member
Hi everyone, new user. Thank you for this forum.

I interview people on Skype (live) and bring them in to OBS.When I first started doing this, I used to use a Logitech C920 webcam on my mac as both the camera for the Skype guest to see me, and the camera that went out to YouTube for the audience to see me.

That started creating a video lag (as the camera was being used twice kind of) So I had the brilliant idea to use my Mac's built in Facetime cam for the Skype guest (kinda crap quality but just so they could see me) and the Logitech C920 was how the audience saw me.

Well this worked like a charm for many months. Up until approx 3 months ago. It's now back to the point where I can raise my hands above my head on camera and count to probably 10 before I see the movement in the OBS preview window.

It has almost killed my show.

Things I have tried:

- Turning off the Mac facetime cam in Skype, so now my Skype guest does not see me at all, but the audience sees me via C920 cam (no improvement)
- Grabbing latest version of Logitech Gaming Software (controls the features of the Camera) (no improvement)
- Deleting the Logitech Gaming Software altogether (no improvement)
- Reducing my OBS scenes to a bare minimum. I'll admit, I had 2 talkshows worth of scenes in one OBS profile. Now I have very simple scenes, intro, main screen with myself and guest, guest full screen, outro (no improvement)
- a 2nd Logitech C920 webcam (while working smooth for maybe a few minutes) probably came back quick. (so, no improvement)
- Thinking problem lied with Mac Hi Sierra, I partitioned my HD and put El Capitain on it and booted to it, with fresh OBS studio there. Same problem (no improvement)
- Using Logitech's "Logitech Camera Settings" app from the app store (mainly to turn off auto-focus as its distracting) (no improvement)
- Using no Logitech software at all (no improvement)
- Made sure nothing is plugged into a Hub. Camera and USB Mixer for audio are all plugged into the back of my iMAC. I assume all USB3 slots from what I am told.

The only thing I have NOT tried is rolling OBS back to an older version. I am leaning towards that. I am currently running OBS STudio 21.1.1

Again to recap, I have Skype configured to use 1 webcam for the guest to see me, (in this case mac Facetime cam) and OBS uses my Logitech C920.
If I have ONLY OBS open and watching my webcam video preview, everything is smooth and realtime. The second I open skype (even as it's opening) I get the slowdown start, and before and during start streaming, I get video delay like mad.

Please keep in mind, all settings for stream and everything else have been untouched from back when it used to work like a race machine. Which leads me to only guess it's something with the new OBS version.

Any thoughts at all? I greatly appreciate any tips. Sorry for the long post, wanted to be as descriptive as possible.

Thank you


New Member
I'm having a similar issue, although the lag for my window capture isn't as significant. There's still a noticeable lag in the Skype window that I've put into my OBS scene. Any help on this would be GREATLY appreciated.

Log file: