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7

The brain can process an image displayed for as little as 13 ms if the surrounding content is blank. 10 to 12 images per second is only the number of images that appear distinct to the eye. Beyond 10 to 12 images a second, the brain starts to try to piece them together, but it is doing a lot of work to make that go and the motion isn't as smooth as it ...


5

At a certain time you can see the rocket at two places at the same time. What you are seeing has nothing to do with compression artifacts, but is frame-blending due to the slow motion effect applied (in the video) Let's say the video is recorded at 30 frames per second. You only have 30 'pictures' per second to capture the information. If you want to ...


4

On DSLRs, a fast shutter can actually be better. DSLRs scan the image to sample rather than capturing the whole frame at once. This is why you get a distortion when you do a rapid pan. A faster shutter will result in stopping motion more clearly (less motion blur), which can seem a little harsher than the softness of film, but a sharper image may be ...


4

In almost all digital video cameras there's no physical shutter, just a circuit that limits the exposure time. As long as that time allows the entire sensor to be illuminated and scanned, you should see no degradation of any individual frame. In this sense, as long as the minimum is met, there should be no visible difference between a fast shutter and an ND. ...


4

48 to 25 should be better because you have more frame information to interpolate, though the contents of the clips could also matter. If all the 48 fps clips are high speed motion while the 25 is relatively static shots, then it will probably interpolate better. The key is that frames are going to have to be guessed at and the less time that passed from ...


4

Yes, repeating every other frame works the same way at 30fps as it does at 24fps. Animating on twos is done not because it looks better, but because it means less drawing and you can 'get away' with it. Nothing stops you from drawing every frame if you want the smoothest possible motion, and nothing prevents you from repeating a frame indefinitely when ...


4

I'm not sure how it will behave at very low frame rates, but it is worth pointing out this would also limit your options on how and when you could change frames since they would have to follow on the clock cycles. What is more likely to work in this case is a long keyframe interval. The majority of frames in a compression like H.264 only store the changes ...


4

The logic of experience. All you have to do is watch 10fps or even 20fps video to realize that what you "know" to be true of the brain is wrong. Persistence of vision in the average human dictates a refresh rate of > 25fps to avoid apparent flicker. The human visual system involves more than just what the brain can completely process.


3

You only need to overcrank the scenes you want to slow down in post. Editing and effects software make it easy to decimate from 60 (or higher) to 24 fps. You'll get better flexibility if you shoot your slomo scenes at a the highest exact multiple of the base rate that still gives acceptable exposure etc. So 96, 120 or 240 fps would be preferable if they work ...


3

In order to convert frame rates without impacting the speed of playback, you have to remove frames to decrease the frame rate or create new frames to speed it up. If the frame rate is an even multiple, then this process can be done losslessly for reduction in frame rate since you simply drop every unneeded frame. If they are not multiples or you are ...


3

You're not back to 60fps, you're still at 30fps but with every other frame discarded (or blended, or interlaced, depending on how the speedup is accomplished). When you discard every other frame, you're trading off temporal resolution. If you interlace, you're trading off spatial resolution. Either way, if this appears smoother, something's wrong with the ...


3

I disagree with the above answers. Our visual culture and the century of cinema has dictated that we evaluate a 180 degree shutter as "normal", because that is how film cameras have worked almost forever, and that is how most scenes in every movie are shot. 180 degree shutter is the same as 1 over twice the frame rate, or 1/48 for 24fps. If there is ...


3

If a person is shown consecutive pictures of a featureless circle at various places on a screen, the person may perceive independent circles appearing and disappearing, one circle which is making discrete (jerky) motions, or one circle which is moving smoothly. Which perception dominates will be a function of both the rate at which the screens are shown and ...


3

"If I set it to 1/25 (shutter speed) does that mean absolute maximum (or lowest setting)?" Yes, if it was a non-digital video camera. This rule applied to the old non-digital (film) video cameras where you cannot set shutter speed lower than the frame rate. Meaning that one celluloid was exposed for the full 1/25th of a second. Assuming 25fps. For digital ...


2

I'm with AJ. Unless you know the characteristics of every player that might view this, it would be unwise to rely on a small sample of test results. Using a standard frame rate like 24 fps with a keyframe interval of 24 frames will give you essentially the same thing with no compromise in compatibility. The intermediate frames will be minimally small because ...


2

Yeah! Welcome to the good ol' world of analog television. When they originally introduced color television and put a high frequency chroma signal on top of the black- and white luma signal, they had to introduce a freqeuncy shift to prevent the signal from bleeding over into the audio .... oh, you don't want to know. Srsly! Even in times of digital video ...


2

You could use multiple cheap cameras recording at low fps, but slightly out of phase. Bennett Wilburn talks about this in his 2004 Stanford Doctoral thesis, "High Performance Imaging Using Arrays of Inexpensive Cameras".


2

The reason we try to shoot at our target frame rate is because if we need to adjust the frame rate, the computer has to invent new frames to go in between our existing frames. This can result in artifacts in the image and generally reduces the quality. You are correct that 24fps is the standard for theater and also correct that you need to shoot a faster ...


2

I think you're out of luck. Official specs say 30fps max, and I can't find any documentation of a possible hack. http://www.nikonusa.com/en/Nikon-Products/Product/Digital-SLR-Cameras/25478/D5100.html The most widely distributed slow-mo camera is probably the iPhone 5s-- I bet you could borrow one to play around with.


2

This type of problem is usually a side effect of the type of compression used. In order to minimise the bandwidth requirements, frames are simplified, reusing content from previous frames etc. And this can cause interesting video effects when key (whole) frames are corrupted or missed.


2

By shooting at higher frame rate, you can achieve great looking and frame accurate slow motion. Interpolation is not going to happen. But if you want to slow down your footage beyond the frames you have, you can use the right tools in your video editor, or Twixtor plugin, but of course it will not give you as good results as a dedicated high speed camera. ...


2

RTP is just a protocol for data transfer, it doesn't contain any specific information about the internals of the data transmitted. The information should be contained in the .h264 stream. The SPS (Sequence Parameter Set) is what you want to look at, it should contain all the meta information you need. Here is a very nice detailed look at how the SPS is set ...


2

That is way out of the h264 specs. According to Adobe After Effects the format constrains for h264 are at min. 10fps so even 2fps are (not, see below) out of spec and could result in issues with some players. So Avidemux seems to allow out of spec settings, that 1 fps isn't possible, is very likely an internal issue with how h264 gets encoded in Avidemux. ...


1

It could also be caused by interlaced source material, where half the image is recorded at a time. Fast-moving objects would be recorded in two different locations. When the interlaced signal is converted to progressive, the two fields are merged to create one frame with two rockets. However, given that there don't appear to be other interlacing artifacts, ...


1

Interesting question. First, here's a question for you: can your supercomputer actually calculate and render, in real time, an animated zoom on images so complex? My guess (only a guess) is that it will need more than 1/30 sec. to complete each frame (let's assume 30 frames per second as a minimal frame rate in which to achieve a smooth zoom). If that's the ...


1

This will not work because of the difference in absorption of light. The scene will look completely different lit by different colors of light and thus each of the frames will not fit together in a sequence. There is no shortcut for capturing high speed video, you need a high speed camera. You can get cameras up to about 240fps at consumer price points ...


1

There are two ways this can be accomplished. The easiest is by using a slow shutter speed. While most DSLRs may be limited to 30FPS and faster, it is possible through the use of third party firmwares to lower that arbitrarily further. As you can see from the details on Vimeo, they were using GH2s with the EOSHD Vanilla hack. This removes many of the ...


1

1080P/24 seems to be the way to go in this case. It's generally considered to have a more cinematic look and both cameras appear to support that resolution and framerate. Youtube has a 24 fps setting and should handle 1080P video fine. As you already said, use All I on your 70D to ensure highest quality.


1

24 FPS should be plenty smooth, anything about 15fps should appear fairly smooth to the human eye. There are two possibilities I can think of, first, you may be encoding to a fairly low compression format that produces large files, if so, your computer may be having trouble displaying the frames in time. This can result in lag or frame skips which make the ...


1

There must be a setting on the camera that you're not describing which causes this shift. The difference is exactly the same as 24 vs 23.976 or 30 vs 29.97, which is the ratio 1000/1001 -- the 'color vs mono' ratio that originated with NTSC color and should have completely ended with digital standards. Maybe that will offer a clue to finding the setting. In ...



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