That’s the video output standard, you have PAL or NTSC.
Pal is the superior European standard, it’s Phase Alternate Line. NTSC is the American standard, it’s from the National Television Standard Council, who picked a US standard back in the 1950’s. Most modern cameras can do both, I always run Pal.
Also I have a set of EV800 goggles, my picture is very clear indeed, easily as good as my Fatsharks with a TrueD V3 in. The receiver in those falls down in multipath environments or at longer ranges faster, but since I don’t fly in either of those situations the difference isn’t a problem. Its not true that you need $300+ goggles to get a good feed.
The more expensive wrap around style are more comfy and the image distortion from the fresnel lens is less pronounced than in box goggles.
Also the wiring can play a huge part in what’s happening with video quality. I have my camera powered through the VTX, with an LC filter on the power feed. I also run a capacitor on my PDB/ESC.
This worked great on everything except my 3”, which records beautiful HD but has a terrible FPV feed. It has a Caddx Turtle V2.
I like mid range cameras better for FPV, I have had the Predator V3, Caddx Ratel and Runcam Swift. The Caddx gave the best picture out the box, plus it’s low light capability was better. All three could be tuned to give a very good picture.
You still haven’t told us what power output you have set etc?
Some pictures of your set up might help too, a wire or PCB edge touching the frame can cause ground interference for example.