See this post of mine in one of your other threads...
Pull up the camera status and what does it show:
In this example, it shows one camera is pulling 4MP mainstream and 0.3MP substream and the others are 2MP mainstream.
If you are looking at more than two cameras on the screen, it will be showing the substream. Only when you pull up one camera will it go to mainstream.
Confirm on the playback that you are viewing the mainstream - left click on the mouse and it will give you the option to see which stream you are watching.
I also know from your other posts that you may be using consumer grade type cameras and some of them can be problematic with
Blue Iris...
I'm still experimenting with Blue Iris. The recordings look jerky. I think it's because the FPS in the mainstream is in the 3-5 FPS range. I made sure to set the FPS at 15, as the optimization guide suggested, but it turns out that my Vivotek camera's FPS only sets the maximum FPS, not a fixed...
ipcamtalk.com