Classic British Flight Sim

I am completely green when it comes to flight simulation. I collide ‘em, I crash ‘em, I fall out the sky with ‘em and I hit anything in sight with ‘em. I do have troubles and it’s a mysterious world for some of us.

However, regarding frame rates, I am a bit bemused by some comments about maximising them.

My company was involved in the film industry for 35 years. We designed and manufactured film equipment which included specialised animation cameras. These are of the stop-motion variety that are used for animation and special effects (ours were used on Superman 1, 2 and 3 and on 2001 - A Space Odyssey, etc.). We also designed and made a stop-motion camera that was capable of running at live action speeds (actually a world’s first and only).

These speeds were 24 fps for film work and 25 fps for television work.

Going to the FSX Help File, it states that ‘film generally runs past the projector’s lens at a rate of 24 frames per second. At this speed, the human eye cannot detect…that the film is actually a series of rapidly changing still pictures’. Additionally, ’By limiting the upper end of the frame rate, the computer doesn’t spend any more resources than necessary to render the selected frame rate. Resources not used to increase the frame beyond that setting can be used for other tasks …’

This might explain some of the posts that have been appearing.

It’s a well known fact that anyone paying to see a film in a cinema is looking at a black screen for a third of the film, whilst the still frames are advanced. Not quite the same with TV.

In view of this, perhaps someone could explain why we need frame rates in the sixties and seventies. Clearly we need the maximum efficient computing power when we are low down and in a densely populated areas (my domain) and any frame rates above 25fps might seem to be a waste of those precious resources.

Ralph

Hi Ralph

I was reading recently (in a scientific journal, but can't remember which one), tha a good proportion of the popultion can determin frame rates considerably higher than the 25 used in television. I believe a figure of around 100 - 120 was mentioned, but I'd have to find the article again to confirm that.
I can certainly see 25 fps, especially when panning the view in Flightsim and also when watching a widescreen film on a 4:3 TV screen, with the film being panned.
As for the best trade off for your system/eyes, the best thing to do is experiment.

Regards

Kevin

Hi Ralph..

I believe the Americans animate at 30fps but they would wouldn't they

I'm not really sure if the film/TV vs Computer comparison is a sound one for any number of reasons. Neither TV nor Film have the burden of system resource overheads that computers suffer nor do they have various system bottlenecks to contend with.. eg, how fast can the processor process the information and pass it to the graphic bus.. how much onboard ram does the cpu have.. how much system ram is installed e t c. All these variables make each experience a different one as we all have different pc's. While we know what should happen.. it rarely does purely because of the diversity of the equipment we use. A movie projector is a movie projector the same as a tv is a tv. The speed the film passes through the gates is universal as (to a large degree) is the tv transmission.

Throw a handful of rice up into the air and see how many come back down again ;-)

ATB

DaveB :tab:

Most of my jerking (insert comment here) is stutters rather than FPS

As you say Dave a lot is going on and it could be that three or four refreshes of the screen could contain much the same image because the system lags.

To see the full benefit of FPS the system would sureley need to me moving faster than the FPS.....if you know what I mean :think:

Garry

Part of what makes it interesting is that the game physics are probably being calculated at a different rate per second than the display. I know in the Strike Fighters series when you bring the frame rate up you get a visual FPS and a game FPS, which is higher. Obviously if the game FPS were lower than the visual FPS you'd have the display updating but not changing because the computer wouldn't have calculated anything new to display. I think this may partly explain why lower FPS in FSX still seem smooth compared to FS9, but even if not it's worth remembering when you're playing with the settings that if you don't give the computer enough time to calculate all the flying, AI, what scenery to render etc. etc. it won't matter that your frame rates are really high because most of them will be displaying the same thing!
I seem to remember that the difference between film FPS, and UK TV FPS means films are 8% shorter on TV than in the cinema. I think the NTSC format does something different by repeating a frame every now and again, otherwise it'd be over far to quickly with their higher frame rate.

DaveB wrote:Hi Ralph..

I believe the Americans animate at 30fps but they would wouldn't they
ATB

DaveB :tab:

Well H-E-double hockeysticks, yes! Everyone knows everything is bigger, better, faster and fatter over here! ;-)

To see the full benefit of FPS the system would sureley need to me moving faster than the FPS.....if you know what I mean :think:

Well.. I think the effect would be similar to the same mate. You don't want to have bottlenecks as your game is never going to run to it's full potential but by the same token.. you don't want the system hanging around waiting. Much depends on how the game engine is written and this is the main difference between FS9 and FSX. After the final FS9 patch.. the game code was such that faster systems would benefit from having the framerate unlocked.. completely the opposite to FSX. To fiddle is the only way!

ATB

DaveB :tab:

Dave, Thanks for your comments. I think that the difference between 25fps here and 30fps in the US may be something to do with the respective main power supplies. We are on 50 cycles and they are on 60 cycles.

Kevin, You are right about seeing the frames whilst rapidly panning. On thinking about it, with film, a rapid pan produces blurring of the image and when this is projected, the action appears smooth (I’m not talking about the eye boggling camera work in the NYPD Blue titles). Digital images do not have this blurring and so the smoothing is missing and this probably leads to individual frames being seen in rapid pan. One of our programs that was used on post production work introduced artificial blurring on digital images for this very reason.

Ralph

I think that the difference between 25fps here and 30fps in the US may be something to do with the respective main power supplies. We are on 50 cycles and they are on 60 cycles.

Yes, of course Ralph. Obvious when you think about it but I hadn't Another one to remember ;-)

ATB

DaveB :tab: