what makes it even more frustrating now is the cars themselves are starting to behave nicely in terms of fidelity
I'm assuming you mean in terms of graphical fidelity, because in term of physics fidelity they have always been great.
Really lacks realism in replays and still shots,
stuff looks so flat and fake once you zoom in with freecams.
I'm 50 / 50 with regards to DOF, sort of torn....
- DOF and stuff like that would look nice, yes, partly because the DOF gives it a TV look, and partly because DOF hides all sorts of graphics anomalies, aliasing, etc. It's amazing how the graphics get transformed (in a good way) just by adding DOF when NOTHING else is changed, not textures, not resolution, not lighting, nothing at all. Just add DOF and BAM replays look beautiful (especially "TV Cam" replays, since it really makes it feel like a proper televised look).
- On the other hand, I wouldn't say that lack of DOF makes it look fake, unless you're comparing it to a televised video-camera / photo-camera look, but in that case a video-camera / photo-camera look looks fake compared to real life, so then having DOF can be itself considered "fake" looking if you're comparing it to real-life, rather than to a television / "photo-mode" look
In real life I can choose to focus on whatever I want, I am not stuck in some sort of "forced to focus on what the camera wants me to focus on, like some sort of movie" mode. If someone feels they need to add in DOF in order to make things seem un-flat and more depth and pop, then they're doing it wrong, they'd be much, much, much, better off by getting themselves an NVIDIA 3D Vision 2 kit, then they'll get much more proper "pop", depth, un-flatness, without having to resort to completely blurring out entire parts of the image as a way of trying to "simulate" a 3D look. Adding DOF is a terrible way to compensate for using a 2D setup.
In terms of adding it, to ones liking, for screenshots....Isn't that what photo editing software is for?
- The best compromise of DOF being used in my opinion, is in a very, very slight way where rather than simulating the EXTREME blur that a camera gives you (depending where it's focused) it instead just uses a very, very slight blur at a constant rate the further and further anything is from the player's "eye point". So essentially it is simulating how things become blurrier and blurrier to any human being the further and further away things get from you. This method would be a much more true-to-life DOF effect than the "video camera telling us where to look, and everything outside that spot is a blurry mess" look.
- EDIT: Just wanted to add a final thought. Yes, the DOF would look beautiful in a "TV" cam replay, but it would have to be toggleable because I often watch replays from TV cam and I also often watch live action from TV cams, including the static mouse-controllable TV cams, and in those cases DOF IS THE LAST THING I would want. I find myself looking at all sorts of different objects around the track, different cars at different points of the circuit, I really feel like I am there in the stands, or standing trackside. DOF would completely RUIN this experience as everything would be a blurred, vaseline mess, and I would not be able to enjoy watching the whole track like I can in real life and in-game without DOF, instead I would be forced to focus on whatever the DOF camera decides for me to focus on and that's it, completely ruining the immersion and experience.
If you've ever watched from TV cams, especially the static mouse controllable ones, on triple screens (especially with multiview), then you'll know what I'm talking about

. DOF would completely ruin this.
- I say
have 3 options that are all toggleable in real-time in-game with the simple press of a button
Option 1 - No DOF at all
Option 2 - The slight DOF I explained above that simulates how things get blurrier and blurrier the further away off into the distance they get from any human being's eye point (this would look awesome while using trackside cams to spectate)
Option 3 - The "popular" video/photo camera look type of DOF that most people are familiar with