I have a simple question. Does anybody know the latency for analog FPV goggles?

Chris Rosser has done a fair amount of testing on this: https://www.youtube.com/c/ChrisRosser/se...ry=latency

You'll need to watch the videos to understand all of the factors that determine latency, but the takeaway is that for most analog systems it's about 20-35ms.

In analog it largely comes down to the camera. Foxeer Predators and T-Rexes, and Runcam Racers are all known to have good latency.

So... the latency is depends only from the camera.? I.E. one of my drone i have the foxeer predator nano which is 6ms. My latency glass to glass is 6ms or depends what VTX and VRX i have.

Not only on the camera, but the camera is by far the biggest factor. For analog there's no encoding - it's a pretty straight line from the output of the camera to your eyes - so the latency introduced in other parts of the system is pretty negligible. It'll be more than the latency of the camera by itself, but the other parts of the system are basically a flat fee that you can't avoid paying!