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I had a small discussion with Agnaa, DMUA, and Armorchompy to see why certain ways of calcing speed blitzing speed feats or speed blitzing time frames were unusable. I realized that virtually most, if not all, ways of calcing speed blitzing feats were not quite valid. We even have sections that forbid the use of time frames from sources where humans have perceived extremely fast objects.
So I was forced to find a new way.
Now the new method I came up with is starting to get used for speed blitzing calcs so I want all of us to discuss the guidelines on how to properly use this method
For those who aren’t knowledgeable on how the eye works and its limitations on what we perceive when it comes to speed here is an explanation.
How do we see? The eyes are the main organs that receive light and allow us to see. When light enters our eyes, it is converted into electrical signals. These signals then travel through different parts of our brain, and eventually reach the primary visual cortex (an area in the brain), which helps us make sense of what we see.
What are the speed limits of what we see? Under normal conditions, our vision has certain limitations that can change depending on different conditions and circumstances. To understand these limitations, researchers conduct experiments under controlled conditions, often involving flickering lights.
When a light flickers very quickly, there is a minimum speed at which we no longer perceive the flickering and the light looks steady instead. This specific minimum flickering speed is called the critical flicker fusion frequency (cFFF) or Flicker Fusion Threshold (FFT). At this point, our eye receptors can't detect the individual changes in what we see anymore. Instead, they merge together, creating a steady signal that our brain interprets as continuous light.
This concept is also applied to TVs, cinemas, and other similar forms of media. That’s why frame-by-frame viewing needs to happen at frequencies close to the limit at which we can perceive “flickering lights” so we can view motion on TV fluidly. At a higher speed than our limit, things would look like they’re skipping frames. Animals that have better vision than humans need to “see fast flickering lights” better to survive in the wild. According to this study, Birds that have a great ability to see “flicker lights” can see fast-moving objects better than humans, especially when these objects could potentially collide with them in the air. [2]
If you want a deeper meaning on how the brain perceives light and what perception blitzing speeds would look like in the brain. See below, otherwise skip to the next point.
Intro
We need light to see. Light bounces off things and goes into our eyes. The retina in the back of our eye collects these things. (The Fovea is a part of the retina that collects colors.)
All that light that’s bouncing off of the moving/stationary things we are looking at is turned into electrical signals that go to the back of our brain. That place in the back of our brains is called the visual cortex. The first neurons in that part of the brain that collect the information is called V1 neurons. Their only job is to react to the light and edges. Anything involving light. Which means flickering light or changes of light in the environment (Changes of light can happen when something moves, so if a red light bouncing off a moving car moves to the left, we would know it moves to the left when it collects the info of light traveling across. In other words, it knows the direction of light bouncing off moving things). Then all that light goes from the V1 neurons from our retina, then it goes to all the other neurons (MT/V5, MST, 7a, all that stuff) that all specialize in motion (basically these neurons answer the following questions is this moving? Is this stationary? Where exactly is it moving? What is it doing? What does it look like when it’s moving? What should I do?), identifying what we are looking at (Wtf is this?), and so on. All of this does not matter because they all depend on the very first neurons to work well (the light detecting and light changing neurons, also known as “flickering lights” neurons). That’s why scientists use experiments that involve flickering lights, because they want to see the limits of this first set of neurons, NOT the following sets of neurons that deal with motion and all that stuff. Because all those other neurons rely on the first ones for perception [3][5]. So if things move so fast that they can’t be seen, it’s because the first set of neurons h don’t have enough light information to send off to other neurons which are used for reaction. The other sets of neurons are based on reactions.
Things can flicker or move at such high speeds that the primary visual cortex (V1) becomes unable to detect the rapid changes in light. Instead, the V1 simply presents the most recent, fully processed information as more light enters the eye. This phenomenon explains why afterimages and other fast-motion-vision-related illusions occur. As the visual system struggles to keep up with the rapid changes, it relies on the last processed image, creating the illusion of persistence and the blending of moving objects into the background, appearing invisible.
In summary, as things move, light changes; as things flicker, light changes. Our brain can only know what is moving if it can detect changing light in the first place. That’s why scientists use flickering lights to determine this, cuz flickering lights and moving objects are essentially just changing lights to first areas of our brain’s visual cortex.
Scientists determine this by figuring out the frequency our brain gives ups on detecting rapidly changing light and fuses the light into one (often the cause of afterimages when things move extremely fast). They do this through experiments that involve showing people flickering lights and speeding it up till the flickering fuses to become one single image of light. At this speed, the brain literally can’t detect changes in light. This is why when characters move at this speed, the brain won’t detect the changing positions of light bouncing off them at different points in space.
So in other words, the minimum speeds that surpass the limits of our vision is called Critical Fusion Threshold, which is also called Flicker Fusion Threshold. That speed is measured in Frequency Hertz. [4]
There are many experiments to find this speed. The most widely accepted being between 50 to 90 Hz like you see in the OP. [6][7] however since things have edges, DarkGarth has proposed that we use 500Hz (1/500th of a second for speed blitzing calcs) based on experiments (see below for more).
These are for Characters who are FTE to the point they appear invisible or cause visual illusions depending on how they move while moving faster than the eye's visual processing.
Dark Garth's Proposal
Therefore, I propose using 1/500s for perception blitzing calcs rather than s reaction time blitzing calcs.
Agree: DarkDragonMedeus (Recent; 1/500s), DarkGarth (Expert; 1/500s), LephyrTheRevanchist (Recent; 1/500s), Dalesean (Recent; 1/500s)
Neutral: DMUA (skeptical, albeit hasn't followed the thread much)
Disagree: DontTalk (outdated; 4 weeks), Flashylights (outdated; 4 weeks)
Due to the inability to gather input from staff members for one reason or another. This thread is considered accepted.
So I was forced to find a new way.
Now the new method I came up with is starting to get used for speed blitzing calcs so I want all of us to discuss the guidelines on how to properly use this method
For those who aren’t knowledgeable on how the eye works and its limitations on what we perceive when it comes to speed here is an explanation.
How do we see?
What are the speed limits of what we see?
When a light flickers very quickly, there is a minimum speed at which we no longer perceive the flickering and the light looks steady instead. This specific minimum flickering speed is called the critical flicker fusion frequency (cFFF) or Flicker Fusion Threshold (FFT). At this point, our eye receptors can't detect the individual changes in what we see anymore. Instead, they merge together, creating a steady signal that our brain interprets as continuous light.
What Does Flickering Lights Have To Do With Perceiving Motion?
People with higher Flicker Fusion thresholds (the ability to no longer see high speed flickering in flickering lights but instead see them as steady light) tend to have better accuracy in what they perceive in general. In other words, people who can see fast “flickering lights” at a higher speed than others, can see fast moving objects at a higher speed than others. [1]
This concept is also applied to TVs, cinemas, and other similar forms of media. That’s why frame-by-frame viewing needs to happen at frequencies close to the limit at which we can perceive “flickering lights” so we can view motion on TV fluidly. At a higher speed than our limit, things would look like they’re skipping frames. Animals that have better vision than humans need to “see fast flickering lights” better to survive in the wild. According to this study, Birds that have a great ability to see “flicker lights” can see fast-moving objects better than humans, especially when these objects could potentially collide with them in the air. [2]
If you want a deeper meaning on how the brain perceives light and what perception blitzing speeds would look like in the brain. See below, otherwise skip to the next point.
Intro
We need light to see. Light bounces off things and goes into our eyes. The retina in the back of our eye collects these things. (The Fovea is a part of the retina that collects colors.)
All that light that’s bouncing off of the moving/stationary things we are looking at is turned into electrical signals that go to the back of our brain. That place in the back of our brains is called the visual cortex. The first neurons in that part of the brain that collect the information is called V1 neurons. Their only job is to react to the light and edges. Anything involving light. Which means flickering light or changes of light in the environment (Changes of light can happen when something moves, so if a red light bouncing off a moving car moves to the left, we would know it moves to the left when it collects the info of light traveling across. In other words, it knows the direction of light bouncing off moving things). Then all that light goes from the V1 neurons from our retina, then it goes to all the other neurons (MT/V5, MST, 7a, all that stuff) that all specialize in motion (basically these neurons answer the following questions is this moving? Is this stationary? Where exactly is it moving? What is it doing? What does it look like when it’s moving? What should I do?), identifying what we are looking at (Wtf is this?), and so on. All of this does not matter because they all depend on the very first neurons to work well (the light detecting and light changing neurons, also known as “flickering lights” neurons). That’s why scientists use experiments that involve flickering lights, because they want to see the limits of this first set of neurons, NOT the following sets of neurons that deal with motion and all that stuff. Because all those other neurons rely on the first ones for perception [3][5]. So if things move so fast that they can’t be seen, it’s because the first set of neurons h don’t have enough light information to send off to other neurons which are used for reaction. The other sets of neurons are based on reactions.
Things can flicker or move at such high speeds that the primary visual cortex (V1) becomes unable to detect the rapid changes in light. Instead, the V1 simply presents the most recent, fully processed information as more light enters the eye. This phenomenon explains why afterimages and other fast-motion-vision-related illusions occur. As the visual system struggles to keep up with the rapid changes, it relies on the last processed image, creating the illusion of persistence and the blending of moving objects into the background, appearing invisible.
In summary, as things move, light changes; as things flicker, light changes. Our brain can only know what is moving if it can detect changing light in the first place. That’s why scientists use flickering lights to determine this, cuz flickering lights and moving objects are essentially just changing lights to first areas of our brain’s visual cortex.
So What is Flicker Fusion Threshold That Represents The Perception Blitzing Speed?
Scientists determine this by figuring out the frequency our brain gives ups on detecting rapidly changing light and fuses the light into one (often the cause of afterimages when things move extremely fast). They do this through experiments that involve showing people flickering lights and speeding it up till the flickering fuses to become one single image of light. At this speed, the brain literally can’t detect changes in light. This is why when characters move at this speed, the brain won’t detect the changing positions of light bouncing off them at different points in space.
So in other words, the minimum speeds that surpass the limits of our vision is called Critical Fusion Threshold, which is also called Flicker Fusion Threshold. That speed is measured in Frequency Hertz. [4]
There are many experiments to find this speed. The most widely accepted being between 50 to 90 Hz like you see in the OP. [6][7] however since things have edges, DarkGarth has proposed that we use 500Hz (1/500th of a second for speed blitzing calcs) based on experiments (see below for more).
These are for Characters who are FTE to the point they appear invisible or cause visual illusions depending on how they move while moving faster than the eye's visual processing.
Dark Garth's Proposal
Having looked through the thread and the sourced information thoroughly, I would be comfortable with this standard. That being said, I don't believe we can afford to brush off the results of the Davis et al. article mentioned earlier in the thread. Despite the previous articles implying a 50-90Hz (20-11.1ms) threshold, this particular article suggests that visual flickers can be observed at as much as 500Hz (2ms). As mentioned earlier, this is in part due to saccades - saccades are a natural aspect of our vision, and even occur to some extent while we are visually fixated on a subject, so we would expect to see them influence our perception in a natural environment. Furthermore, the article sheds light regarding the variables that influence this perception:
"We presented users with a modulated light source, and asked them to determine the level of ambient illumination under which flicker was just noticeable. We performed experiments both with spatially uniform light resembling most prior studies on the critical flicker fusion rate, as well as with a spatially varying image as would be common on display devices such as TVs and computer screens... In our experiments, uniform modulated light was produced by a DLP projector and consists of a solid “bright” frame followed by a solid “black” frame. The high spatial frequency image is first “bright on the left half of the frame and black on the right”, and then inverted. We observed the effect described in this paper whenever we displayed an image containing an edge and its inverse in rapid succession. The effect was even stronger with more complex content that contained more edges, such as that in natural images. We chose a simple image with a single edge to allow our experimental condition to be as repeatable as possible... When the modulated light source is spatially uniform, we obtain a contrast sensitivity curve that matches that reported in most textbooks and articles. Sensitivity drops to zero near 65 Hz. However, when the modulated light source contains a spatial high frequency edge, all viewers saw flicker artifacts over 200 Hz and several viewers reported visibility of flicker artifacts at over 800 Hz. For the median viewer, flicker artifacts disappear only over 500 Hz, many times the commonly reported flicker fusion rate."
To broadly summarise, then, flicker becomes more noticeable at higher frequencies when the shapes depicted are more complex and contain more edges, capping out at around 800Hz for a simple image with a single edge, and with a median of 500Hz. The problem that this article identifies with previous research on the topic is that we only find the 50-90Hz rate described by many previous articles when we use a spatially uniform source without a defined edge, such as a pulsating light fixture, and that the frequency at which we can detect flickers is significantly higher for the kinds of more complex, defined shapes we would observe in a natural environment.
While I would like to focus primarily on the objective evidence here, and not simply an unverifiable anecdote, I would also like to mention in passing that most people (including me) who have seen displays with variable refresh rates (i.e.: monitors that can go between 60-120Hz) can see the difference in image changes - there are some monitors that go upwards of 300Hz, and while the jumps are known to have diminishing returns, the differences produced are still noticeable.
If we're going to use this standard as a baseline for calculating feats in the future, we need to acknowledge the evidence that our ability to perceive differences in visual stimuli are much higher in natural circumstances than they are when observing spatially uniform stimuli. As a hypothetical example: if Person A was looking at Person B, and Person B travelled fast enough to vanish/appear somewhere else via speed alone, then the fact that Person B is a more complex shape with a defined edge (try picking someone up with that line) would suggest Person A's ability to detect changes in Person B's position should be far better attuned than it would be for a spatially uniform pulsating light. For that feat, I would suggest then that a 500Hz baseline is more congruent with the evidence.
Guidelines
- The observer's eyes must meet specific visual criteria. They should be able to focus clearly on the object before making any observations. Note that the flicker fusion threshold is dependent on the Field of View (FOV), with the optimal FOV being the center of view.
- The flicker fusion threshold is influenced by the brightness intensity of the surroundings. Observations of feats in extremely dim or overly bright environments are not suitable for this method.
- These guidelines are applicable only to observers with human eyes. For animals, specific studies detail the flicker fusion thresholds for various species. However, the range of studied animals is limited, and findings might not apply universally.
- The object under observation should be unique. Duplications can distort frequency, creating illusions of speed.
- Small or distant objects are challenging to monitor consistently. They are not recommended for reliable speed calculations.
- Techniques that induce afterimages or illusions are not acceptable. There should be concrete evidence that any perceived speed or disappearance of the object is due to its actual speed. If there's any ambiguity, an alternative standard should be considered.
- Any character with a perception speed differing from human standards is excluded, as this can result in skewed speed values.
Therefore, I propose using 1/500s for perception blitzing calcs rather than s reaction time blitzing calcs.
Agree: DarkDragonMedeus (Recent; 1/500s), DarkGarth (Expert; 1/500s), LephyrTheRevanchist (Recent; 1/500s), Dalesean (Recent; 1/500s)
Neutral: DMUA (skeptical, albeit hasn't followed the thread much)
Disagree: DontTalk (outdated; 4 weeks), Flashylights (outdated; 4 weeks)
Due to the inability to gather input from staff members for one reason or another. This thread is considered accepted.
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