Frames Per Second: Fact & Fiction

[Maverick2002]

This was actually one of the places that prompted me to write this little editorial, so I thought I'd share it with you guys. HERE

 

[rbV5]

I appreciate your effort, but your "editorial" is full of factual errors.
Example:

The most common "frame rate" on a television set is 24......

Televisions certainly do render frames, frames are made of fields, each field consists of every other scan line, 1 field of the odd scan lines, 1 field of even scan lines. Each field is displayed(or rendered) every 1/60th of a second for NTSC and every 1/50th of a second for PAL. This results in a framerate of 30 fps for NTSC and 25 fps PAL, and the corresponding refresh rate of 60Hz for NTSC and 50Hz for PAL. This is commonly refered to "interlaced video" as in, each frame consists of 2 fields "laced" together, it is a constant framerate, certainly not a "range" as you suggest.

More to follow.....

you can't notice the flicker of a 60hz monitor looking head on

Actually I can easily see flicker at 60Hz on my monitor looking straight ahead.

Current LCDs don't have higher than 30-40hz refresh rates, but they're progressive. So things may look blurry, but they won't be choppy

You are mixing up your terms, when you are talking video display, the term "progressive" refers to how the video is displayed. Progressive means that ALL of the lines in a frame are displayed in one pass from top to bottom before the next frame appears, this is how all modern CRT monitors and DTV display video, as opposed to Analog broadcast television is displayed how I describe above. LCD's in digital mode however, don't actually "refresh" in the traditional sense, instead each pixel is turned off and on when a different instruction is sent, otherwise, they just stay the same.

Try this: find an older video card (or underclock what you currently have) that will only run 1600x1200 at 40fps without any special features. Chances are it'll look smoother because you don't have anisotropic filtering enabled

I'm sorry, but 40fps is 40fps whether you have AF enabled or not.

 

[merlocka]

I give it a 6.5 for effort but a 3 for content.

 

[Jeff7]

you can't notice the flicker of a 60hz monitor looking head on

Geez, I can see flicker at 75HZ! I use 1280x1024 as my gaming resolution - my monitor can support 85Hz refresh. I'd prefer higher, but yeah well.

Current LCDs don't have higher than 30-40hz refresh rates

LCD's don't even have refresh rates from what I've read. The issue with LCD's is pixel response rate - how fast the pixels can change their colors or brightnesses. Otherwise you get the streaking or ghosting of older LCD's.

Your rates drop from 150 down to 40. Naturally, it looks like crap. Why? Several reasons

If the lowest is 40, it should still be smooth. That's my experience anyway. 30fps or lower - then it can get bad.

 

[BFG10K]

Furthermore, eye sensitivity is different throughout (you can't notice the flicker of a 60hz monitor looking head on, but it's quite obvious when gazing sideways)

I can notice flickering at 75 Hz head on, much less 60 Hz. I take your point though - eyes differ in sensitivity depending on how you look at things.

A lot of people despise vertical sync, as this caps your maximum frame rate to that of your monitor's refresh rate (assuming we're talking CRT).

Vsync does much more than this.

Chances are it'll look smoother because you don't have anisotropic filtering enabled.

I'm not sure if I agree with you on this. It's possible that very low framerates don't look as bad at low detail levels as they do at high detail levels but I've never really tested this.

More importantly, however, is adaptation. If you've played games at 40fps all your life and haven't seen otherwise, it'll look pretty good to you.

For most people, yes. However some people aren't satisifed even if they've never seen anything better, like me when I first started 3D gaming. In those days everyone was happy with 25-30 FPS but I hated it.

I bet if you play at 250fps (possible, but only with older games at low resolutions) for a couple weeks and then go down to 125, you will see a difference.

Agreed.

If the lowest is 40, it should still be smooth.

40 FPS is well below the required threshold for smoothness. Generally speaking I start to notice significant slowdowns when the framerate starts to dip below 60 FPS.

 

[Maverick2002]

rbV5: so why do action stills look blurry on a TV set then?

Current LCDs don't have higher than 30-40hz refresh rates, but they're progressive. So things may look blurry, but they won't be choppy

Ok, that was bad wording. But don't they have 30-40hz pixel refresh rates?

Have you actually done the test I proposed with AF?

 

[rbV5]

so why do action stills look blurry on a TV set then?

Basically because the action in the scene moves during the exposure while filming. When you play the frames together, the motion looks smooth because the blurred action "blends" together.

 

[Gosharkss]

I?m no expert on the software or all of the video cards on the market, but I do know a little about monitors.

You are assuming monitors draw an image frame by frame this is not true.

Monitors and TV's draw images on the screen line by line not frame by frame. A typical monitor running 1280 x 1024 at 85Hz draws a horizontal line every 11 microseconds or 91146 times per second.

Depending on the hardware and software used it is possible to start drawing lines from frame number one then update and start drawing lines from frame two and so forth on a line by line basis. Although I doubt this process is linear, it seems realistic to me that higher frame rates would be interpreted and displayed and would give a better mage on the screen.

 

[MrCoyote]

My comment is not for games, but for film...

I just wish Films in theatres would use a higher framerate than 24fps. This is just too slow for fast action scenes. Next time you are in a theatre watching a movie, look carefully as the camera pans left/right in a moderately fast scene. The motion looks very choppy to me. There is a company called Maxivision that has a very good idea to up it to 48fps. Their new projector is backwards compatible too, and will only use a little more film, because the frames are closer together on the film. Very ingenious. Too bad it doesn't look like 48fps will never happen in theatres.