I’ve been working on getting my FZ1000 to look realistic, using SOOC (Straight Out of Camera) settings, and I’m pretty happy with what these settings now (and it’s REALLY EASY TO REMEMBER). These settings are mostly for 4K PHOTO mode use, so I'm also doing this so I can either use 4K PHOTO mode to grab stills, or to shoot video and be able to use it without doing color grading (though it may need a little sharpness adding in Davinci Resolve, my video editing software of choice…also super good for color grading). Note that the smaller sensor on this camera produces a little bit more NOISE than I would consider perfect, but it's not bad if you look at it as kind of an organic "film look".

IMPORTANT NOTE:
One setting that you have to be careful to not forget, is to set the "Luminance Level" to 0-255 (not the default setting of 16-255). The easy way to set it to 0-255, is simply to switch to 4K PHOTO mode (which will default to 0-255). You can set it without doing that, but it's a lot more difficult (I don't remember the exact sequence).

I should also say, I've found ISO 200 to create the most real-looking image on this camera (maybe it's the "native ISO"?) So, if you can use ISO 200, I do recommend it even over 125 and 160, even though they're lower. The image degrades noticeably above ISO 400, and I sometimes go up to ISO 800 when needed, but be aware that it's going to look like it has more "film grain" (which isn't always bad, but it won't match your other footage, if the other footage was shot at a lower ISO).

Another thing to note, is this camera doesn't work with a VND (variable ND) and so if you need to use a ND filter outdoors (to follow the 180-degree shutter rule, which I sometimes do not) the only option is using a straight ND filter (ND8 has been the best strength in my experience). This is both interesting and somewhat distressing, and the inclusion of internal ND filters in the FZ2500 seems like an admission of this issue. What happens is, at the longer telephoto focal lengths, using a VND filter makes the image look really bad; so bad, you would have to try it yourself to believe it! It's interesting that a similar thing happens with a lot of the 70-300 lenses I've tested (also at and near the long end of the zoom range). My theory is it has something to do with the enormous amount of space between the optics when the lens is in the extended telephoto position.