Turn off the Frame Blending. It's not intended for for use with high-frame-rate video. See what happens.
It would also help to know how you intend to use the video. Are you conforming the frame rate to create slo-mo?
Are you using the footage at its original frame rate in a standard-frame-rate comp like 23.976, 24, 25, 29.97, 30, 59.94 or 60?
Did you try other frame blending modes? There are several.
How did you create the "real" composites?
Shooting 1200 fps and then frame blending the swish pan following the car so the car stays sharp but the background blends into a surrealistic blur is an interesting idea that I have not ever tried. I have a lot of experience sooting at 500 (photonics 16mm) and a fair amount of footage at 20,000 fps - rotating prism cameras to see things breaking under high pressure, but I've never frame blended these razor sharp frames into a simulated motion blur. We shot at high frame rates to capture sharp images to see exactly what was going on in a fraction of a second. I'm not sure exactly how I would handle the task of shooting 50 frames and blending them into one.
Normally blending frames involves blend modes or pixel motion estimation that usually is pressed into service the other way around - shoot normal and then create slow motion by estimating the position of the pixels in the non existent frames. I would love the opportunity to see 50 of these HFR frames so I could measure the change in position between the last and first and see how they could be successfully blended into a simulated motion blur. I'd like to see how it looked compared to a similar shot with an exposure time of 1/51 of a second - the normal exposure of a film camera shooting 24 fps with a 170º shutter.
Guys, the problem is not with me I've done numerous amounts of tests.
Imagine recording a game. The recorder does 60 FPS. You can slowdown the game to 5% speed. When you record 60 FPS at 5% game speed it technically means that when you speed it up to 100% In after effects, that 5% gets sped up by x20. Because 5 fits 20 times in 100. To do the math 60 times 20 equals 1200 FPS. All that put into a composition that is 25 FPS output. If a footage that is 1200 FPS is put into a composition of 25 FPS output what you would see is 48 Samples per frame, or frames per frame, because 48 times 25 equals..? that's right 1200 FPS. But the problem with after effects is that it only allows you to see 12 Samples per frame. Meaning that the higher the FPS of a footage is, the less motion blur it has because taking 12 Samples of objects that are getting closer and closer together means that most of the frames being picked are closer to one another.
This is not me trying to find a solution, there is none. Adobe have to get their stuff together and remove the limit because it pretty much makes shooting at high FPS pointless if all you're doing is shooting at that FPS for the motion blur. We're not talking about slow-motion here. Only what is being generated after the frame blending switch is enabled for the footage. The other frame blending switch is not for motion blur its for slow-motion so don't even suggest that because you obviously have no idea whats going on here.
Sorry, you are not explaining yourself very well. I believe that you have done numerous tests. Don't take offense but by reading both posts carefully I still don't understand what you are doing and what you are trying to do. The only thing I am pretty sure of is that you are not shooting video at 1200 frames per second because you said you are doing a screen recording of game play.
If you film at 60 fps then the effective shutter speed is 1/120 second. In a film or video camera you can decrease the exposure time by changing the shutter angle or exposure time but you can't make the exposure time longer than 1/120 of a second without starting to create duplicate frames in your video or without slowing down the film in a film camera because it takes time to move the film from one frame to another. If you are recording video or shooting film at 1200 fps then your effective shutter speed cannot be slower than 1/2400 second unless you have a high speed video camera with a shutter that I have never used or seen or you are using a rotating prism film camera. In that case the minimum shutter speed would be 1/1200 second.
If you are doing a screen recording then the effective shutter speed is the refresh rate of your monitor/GPU which may be more or less than 1/120 of a second. My problem is that I do not understand your workflow or what you are trying to do because your explanation does not make sense to someone that has been shooting high frame rate footage for more than 40 years.
Slowing down game play by 5%??? - do you mean that you run the game at 5% speed and record that game at 60fps? I am not a gamer so I don't know if that is even possible. If that is what you are doing what do you want to do with the screen recording?
Did you mean that you record the game at 60fps and want to slow it down to 5% so that 1 second of game play takes 20 seconds? Changing the speed from 100% to 5% is not slowing it down, it's speeding it up. If you want one second of real time to be 20 seconds of screen time then the speed 400% not 5%. Your 1200 fps effective frame rate is a mis calculation and does not make much sense. 1200 frames played back at 25 frames per second means that 1 second of real time takes 50 seconds of screen time. The actual frame rate you would use to slow down real time to so 1 second took 20 seconds would be 20 X 25 which is 500 fps. No matter how I look at your math your calculations are incorrect.
When you say playing back at 5% what do you mean? If you adjust the speed of a clip to 5% then one second becomes 6 frames at 24 fps. Did you want to go the other way so that one second becomes 20 seconds? If so that means that you want the speed to be 400%.
I believe your images. I understand that you are disappointed with the way AE handles frame blending. I still don't know how you created the "Real" samples because you didn't answer my second question. I don't know what you are trying to accomplish or what your workflow is. I agree that frame blending when changing frame rates of your footage in After Effects is not as good as it could be. There are better 3rd party options out there that do a much better job of calculating the vectors between moving pixels and create new pixels to fix the problems. If you are just complaining to Adobe then I understand that. I do it all the time. If you are looking for a solution to your problem then we need to understand your workflow and your goals. So far none of your math or your explanation makes much sense. Nothing in either of your posts makes me think that you actually have 1200 fps footage that you are trying to work with. Even if you do actually have 1200fps original footage I have no clear idea what you are trying do with it. If you are simulating 1200 fps footage then your math is wrong.
If you want Adobe to spend more time and money improving frame blending and none of the built in options do it for you then file a feature request. I do it all the time and some of mine have actually been implemented over the last 20 plus years.
Alright I'll try to be pretty plain here. Since it's hard to understand my recording method imagine you have footage that is 1200 FPS.
When you put that footage Into after effects it recognizes it as 1200 fps. When you put it in a composition that is 25 FPS the footage
is real-time. Here is probably where you get lost, imagine you just put the footage in the composition that is 25 fps and when you hit space the movement you see on screen is in real time. Like from point A to point B an object moves the same as it does in real life. But you have no motion blur because the frame blending option is not enabled. When you enable it on the layer that is 1200 FPS after effects shows you 12 samples forward, which creates the illusion that is so called motion blur. But the problem is that 1200 FPS crammed into a 25 FPS composition has more than 12 samples in a frame, it has 48! 1200/25=48 But After Effects has a limitation that only makes us see 12 of those 48 samples, resulting in less motion blur, way less.. As shown in the "REAL" 1200fps. Oh and i achieved the 'real' one by placing the footage in sony vegas and enabling re-sample. Its the same as after effects' Frame blending "frame mix" option.
OK, I got you. Like I said before AE has several variations of frame blending. If you want Adobe to spend money improving the blending then file a feature request. I'm not arguing with you, just trying to understand what you are doing with the footage. If you want to make HFR footage look like normal footage and that's all you want to do then AE is not the most efficient tool for that job anyway. Premiere also has new and improved frame blending options and it may do a better job than AE. If Vegas does the job for you and does it quickly you should be using that tool.
I have not experimented with 1200 FPS video because I don't have any sources for 1200 fps footage. I could load an image sequence into AE but the max frame rate that I can interpret an image sequence is 999 fps because that's the maximum frame rate that AE will recognize and interpret according to the documentation. I would be surprised if AE could interpret video at any higher frame rate than that. The info may read 1200 fps in the info displayed in the Project Panel when the footage is selected in AE but I would be surprised if it is interpreted at any more than 999 fps. I'd like to see a screenshot of the file interpretation panel.
Your 48 samples - 24 before the frame and 24 after is correct math but that's not 5% speed so I don't know where that 5% comes from or what it has to do with the frame blending problem.
I also have no idea where you are getting 1200 fps game capture footage. I know how to shoot 1200 fps video but I do not know of any screen capture system or GPU that cranks out 1200 real frames per second. The only HFR display that I have ever captured using a screen capture rate actually had a bunch of duplicate frames in he screen capture.
I agree that AE's frame blending could be better. It is vastly improved. Handling HFR footage is also much improved, but the usual reason for shooting HFR footage is to slow down the action, not to play it back in real time with simulated motion blur. I can see a reason to start in real time with motion blur and then slow it down or to start in slow motion then speed it up to real time, but I would not use speed controls for that, I would use time remapping and adjust the simulated motion blur by experimenting with AE's different frame blending modes and probably use CC Force Motion blur to polish off the look.
To understand the 5% thing, basically when i say i shoot at 5% speed it means its slowed down to 5%. The game's engine allows the game to get slowed down to 5% and when you record at 60 fps at 5%, speeding it up to 100% makes the footage technically and practically 1200 fps. I know where the confusion comes from. After effects' stretching mechanism is reversed. for it 5% is faster and 500% is slower for example. But In games 5% playback speed means it plays back 20 times slower. By putting the footage in after effects and in the stretch i enter 5% it gets its real time playback. That's how i've made This trailer for example. NaturalVision ✪ Remastered (4K Graphics Trailer) GTAV - YouTube
It was recorded like this. 5% Speed in game(meaning slowmotion) at 60FPS equals 1200 FPS when sped up. Problem is i could've made the trailer way better if we could see more than 12 Samples per frame.. I cannot use vegas anymore because its just not applicable for me. I use only Premiere and After Effects. Premiere has the same problem so i don't bother even going there searching for a solution.
Where can i file a request feature?
If one second of slow motion game play takes 20 seconds and the refresh rate of your screen is 60HZ then 20 seconds contains 1200 frames so you are right about an effective 1200 fps. However I doubt that AE can actually interpret the footage as 1200 fps because the maximum value for AE is 999 fps. Just changing the speed to 5% won't give you an exact frame for frame sampling of 48 frames or make game play exactly real time.
If you want to smooth out the motion blur try adding CC force motion blur to the comp. It's bit of a processor hog but it does a fine job fixing motion blur problems.
From Google: Feature Request/Bug Report Form - Adobe