I think you're mixing up a lot of related but critically differentiated things here, so I'll try to separate and tackle them individually.
QuoteI do agree that raw digital has an artificial feel to it though
That's not actually what I was saying. Regardless of digital or film, the frame rate makes a difference, and it's frame rate that I was specifically referring to above. The process of adding back in grain/noise to match the look of film, or doing tonemapping/color grading to match a particular film look, is quite separate from what frame rate the digital *or* film video is shot at. It's the frame rate itself that looks different.
Surprisingly enough, faster frame rates don't look as "good" to many viewers. It's not even necessarily a question of real vs. not real-looking, but rather association, that people have grown to associate film (and, critically, its relatively slow frame-rate) with "high quality", whereas the faster (comparatively) frame rates of e.g. video, especially home video, have become synonymous with "low quality". Historically this was true for a number of reasons, including quality of non-film equipment, lens availability, etc. and the association of film = quality made some sense, despite the lower comparative frame rate (in all other respects film was better). Now, however, with e.g. dSLRs, RED, and many other high quality *and* high frame rate video recording systems, the association is partly obsolete. Yet we still maintain the learned *feeling* that the typical frame rate of film (24fps) is "high quality". It's quite interesting, but a bit frustrating as it has the potential to hamper improvements in video standards.
Now, regarding "ideal frame rate" and "realism", Martin is right that quantifying the limits of our visual perception is extremely difficult, in large part because it varies across our perceptual frame (center of the eye vs. periphery, for example), but also because we're trying to map limits of analog systems (eyeballs, brain) to digital systems (pixels, frame rate). It used to be thought that 60fps was the limit of human vision in terms of frame rate, and indeed tests can show this to be somewhat the case as far as direct, conscious perception, yet there are many aspects of perception that work partially or entirely subconsciously and may not show up on tests of conscious perception, such that differences at 120fps or even higher may be perceptible in some circumstances. All that being said, one must also contend with the limitations of current video standards and output ability, and 60fps is all anyone is really targeting right now at the top-end.
In answer to your questions:
QuoteWould at a high frame rate the figures movements as he walks look more real compared to a low frame rate?
and
QuoteNow imagine a camera flyby of a terrain. Would at a high frame rate the imagery look smoother, more like what the eye sees from an aircraft?
Both really depend on what you mean by "more real" and "what the eye sees". It appears to be the case that our perception of "realistic" varies with context. What looks "realistic" when we're watching a video is not necessarily a direct correlation to what is technically speaking the best representation of reality. 60fps ought to look more "real", but we expect 24-30fps and associate that with high quality content (e.g. movies), and so many people actually perceive 60fps to look "too much like video" and therefore not realistic. Many say it looks "unnatural", though perhaps what they actually mean is "hyper-real", hard to say. There is also of course the difference between looking "good" and looking "real"; 60fps may look more "real", like you're actually standing there (I would argue that's the case), but at the same time it somehow looks *worse* from an aesthetic perspective (in my experience). It looks cheap and artificial. This is really just down to our learned associations and biases with film vs. video and the associated factors of each, which include frame rate.
So with all that in mind I still maintain that 30fps is a more practical and useful goal because the improvement over 24fps is significant, and the render time increase is less so. In other words your net gain from the sacrifice of longer render times is proportionally greater with 30fps vs. 24fps, and it diminishes the higher you go from there in terms of perceived increase in motion smoothness. To say nothing of the aforementioned problem that the specific 24fps frame rate is seen by many as more "realistic" because of the association with film and the expensive equipment with which it is made.
The problem with demonstrating any of this is it depends heavily on the output device and playback methods. Your monitor probably displays things at a minimum of 60hz, so should be able to display a video at 60fps. Likewise there are PC video players that can do 60fps. Finding native (filmed at) 60fps content is a little harder, but not that bad, though you need to make sure that it's actually being displayed at 60fps! Youtube, for example, converts uploaded 60fps video to 30fps, as does Vimeo and most other hosting sites, so you can't just go to Google and expect to easily and quickly find online streaming videos at 60fps. Even if you do find a 60fps video to download, many desktop video players do not play at 60fps, or at least not by default. Then it's further complicated by the fact that taking 60fps video and converting it to 30fps won't necessarily give you the same result as filming natively at 30fps, so the ideal comparison would have 2 otherwise identical cameras filming the same scene at the same time, one at 60fps and one at 30fps. I imagine such comparisons have been done but I haven't seen them.
All this should really start to tell you that 60fps is neither common nor well supported and so even if you do choose to go for it for "maximum quality", the portion of your audience who will actually get to enjoy it as intended is going to be small. So again in my opinion it's simply not worth it right now. You double your render time for the benefit of a very small minority of people, and even those who can see it might think it actually looks *worse*! (see above regarding the perception of film vs. video related to frame rate)
- Oshyan