Image noise is a random variation of brightness or color information produced by a photo film or digital sensor. Image noise is an undesirable by-product of photography and does not come from the actual objects in the picture.
Image noise can be in the salt-and-pepper type, forming bright dots in the dark parts of the image. When appearing in the dark part of the Moon, flat-Earthers incorrectly claim they are stars, “proving” that the Moon is transparent. In reality, these are just image noise, not part of the actual objects.
Continue reading “Image Noise and The “Transparent Moon” Misinformation”
By utilizing perspective compression, it will be easier for us to observe the curvature of an object if the object is curved.
Flat-Earthers like to deliberately choose a vantage point where it is difficult to see Earth’s curvature, and they use it to “prove” the curvature does not exist. In reality, they only make it more difficult to see the curvature. It does not mean the curve is not there.
Continue reading “Perspective Compression: Determining If a Curvature Exists”
At the cruising altitude of a jet airliner, Earth’s curvature is too slight for us to notice casually. But with planning and careful observation, it is not impossible to see the curvature. Continue reading “Observing Earth’s Curvature From a Flight”
If Earth is a sphere, how is it possible for flat-Earthers to show us “images of flat Earth” taken from high-altitude balloons? These are the modus operandi of unscrupulous flat-Earthers to obtain such images in an attempt to deceive us.
Continue reading “Modus Operandi of Flat-Earthers to Obtain “Images of Flat Earth” to Deceive Us”
Cameras used by Apollo astronauts were equipped with ASA 160 film (equivalent ISO 160 in digital cameras). And they were instructed to use the following camera exposure values: shutter speed 1/250s, aperture f/5.6 (in shadow), and f/11 (sunlit). We can try the same values to everyday scenes and see how they end up in the results.
Stars are not visible in the photos from the Apollo missions, and flat-Earthers use the fact to dismiss them as fake. In reality, by using the same exposure settings as the astronauts used, we cannot get the stars to appear either. Therefore, there is no reason to expect stars to appear in photographs taken by Apollo astronauts.
Continue reading “Camera Exposure Settings in the Apollo Missions”
Cameras with a fisheye lens are used in the ISS, high-altitude balloons, rocket bodies, and other purposes. The reason is that fisheye lenses have several advantages over rectilinear lenses.
Flat-Earthers claim there is an evil intention behind the usage of fisheye lenses. In reality, the use of fisheye lenses is not unreasonable. If it is desired to have a rectilinear image output, then it is not hard to defish fisheye images to rectilinear ones..
Continue reading “Why Fisheye Lenses Are Used”
Flat-Earthers and other conspiracy theorists incorrectly claim that the shadows in photos taken on the Moon in the Apollo missions are inconsistent. In reality, it is just due to their confirmation biases, and we can easily explain how the shadows were formed.
The perspective effect can cause parallel shadows to appear angled to each other and converge to a distant point. Conspiracy theorists incorrectly claim that non-parallel shadows can only be caused by a nearby light source.
Continue reading “Shadows in Photographs Taken on the Moon”
It is impossible to positively prove the authenticity of a photo beyond any doubt unless we take the photos ourselves. Instead, we gather as much information as possible related to the photo, evaluate the information, then use inductive reasoning to determine if the photo is real. And the conclusion will always be a probability, not a certainty.
Flat-Earthers like to demand us to prove that a particular photo is real, and if we cannot, they will conclude the photo is fake. In reality, while we might be able to prove a photo is not real, at the very best, we can only say there is no reason to believe the photo is not real from all the available information. This applies to practically all photos and also plenty of other things in everyday life.
Continue reading “Determining the Authenticity of a Photo”
Stars are dim. We can only see them if our eyes are adapted for low light. Astronauts in space can see the stars when the sun is blocked from view and avoid seeing any large sunlit objects.
Some astronauts said they did not notice the stars, but others claim they could see them. Flat-Earthers use the conflicting statements to discredit spaceflight. In reality, sometimes astronauts can see the stars, and sometimes cannot, just like us on the ground, depending on the situation.
Continue reading “Seeing Stars in Space”
Visibility is a measure of the distance at which an object can be clearly discerned. Visibility depends on the transparency of the air. There is no air in space to disrupt the transmission of light, and therefore, light can travel very far in space practically undisturbed.
The ISS can be seen clearer than objects on Earth’s surface far closer than the ISS. Flat-Earthers use the fact as “evidence” that the ISS is much closer. In reality, only a fraction of the light path from the ISS travels through the dense lower part of the atmosphere that will significantly affect the transmission of light.
On the other hand, light emitted by objects on Earth’s surface has to travel the entire path through Earth’s atmosphere.
Continue reading “Visibility of Objects in Space Compared to Those on Earth’s Surface”
The sunlit part of the moon is far brighter than the stars in the background. But cameras have dynamic range limitations. They cannot capture extremely bright and extremely dim objects at the same time. We can increase the exposure to reveal the stars, but then the moon will appear washed out, with no visible details.
Flat-Earthers use the lack of stars in photos taken from space to dismiss them as fake. In reality, the reason for the lack of stars is the same reason stars are also missing in photos of the Moon taken with the correct exposure.
Continue reading “Camera Exposure Settings to Capture the Moon and Stars”
With careful planning, we can easily observe Earth’s curvature from an airliner. To “explain” the observation, flat-Earthers invented the excuse that it is caused by the distortion from the shape of the airplane’s window.
In reality, all camera lenses are curved, too, yet most of these lenses produce normal, rectilinear images. The fact that the shape of the window is curved does not mean looking through the window will produce a curved horizon.
Continue reading “Curved Airplane Window and Observation of Earth’s Curvature”
Visual albedo is the measure of the reflection of sunlight out of the total solar radiation received by an astronomical body, taking into account only the visible light. The visual albedo of the Earth is 0.37, and the Moon’s is 0.12.
The Moon appears dark if the Earth also appears in the same photograph. Flat Earthers use the fact to dismiss such photos as fake. In reality, the Moon’s brightness in a photo is just a matter of choosing the correct camera exposure. But if Earth is also present, increasing the exposure will make the Earth appear too bright.
Continue reading “Visual Albedo of the Moon and the Earth”
Glare can appear around light sources, causing them to appear larger in a photo. The higher the exposure value of the camera, the larger the glare will appear on the resulting photo.
Much flat-Earth misinformation arises from misunderstandings about photography, such as about glare and how to eliminate glare by changing the exposure or by using a solar filter. Using the exposure setting for everyday scenes to capture a photograph of the sun will give us a glare around the Sun. To take a photo of the actual size of the Sun, we need to reduce the exposure, either by changing the in-camera exposure settings or by using a solar filter.
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Flat-Earthers often show us images of a lamp illuminating a dark wall to demonstrate —incorrectly— how night can happen on a flat Earth.
In the images, the areas farther from the lamp appear dark. Due to the inverse-square law, areas farther than the source of light receive less light. However, these areas still receive light nonetheless. From these dark areas, the lamp is still visible. This contrasts with what happens at night, that sunlight is nonexistent and the sun is not visible.
Continue reading “Lamp Illuminating a Dark Wall Demonstration”
DSCOVR is a spacecraft positioned in the Lagrangian point L1 between the Sun and Earth. It carries the EPIC camera that continuously takes images of Earth in 10 wavelengths from 317nm to 780 nm in rotation.
The Moon can appear in EPIC images, and flat-Earthers incorrectly use the color fringing around the Moon to dismiss the images as fake. In reality, the full-color images are composite of three single-color images taken in consecutive exposures in a one-minute span. As a result, the Moon had shifted in the time span and not perfectly aligned in the different exposures, causing the color-fringing after the images are composited together.
Continue reading “Lunar Transit Images from DSCOVR-EPIC”
Because of a perspective effect, an observer in space can see more of Earth’s surface if they are farther from Earth.
Flat-Earthers noticed the different visible Earth’s surface in different Earth images and used it to “prove” they are fake. In reality, it is just a perspective effect caused by the fact that the Earth was seen from a different observer distance.
Continue reading “Perspective of Earth Due to Different Observer Distance”
The images showing the progress of a lunar eclipse were taken in increasing exposures to compensate for the decrease in brightness. The exposure increase from full moon to totality can reach 12EV or 4000× increase in light-gathering power.
Images showing the progress of a lunar eclipse appear in a constant brightness, and flat-Earthers —presumably never seen it in person— use it to “prove” a lunar eclipse is not caused by Earth’s shadow. In reality, the images were kept in a constant brightness by increasing the exposure of the camera.
Continue reading “Constant Image Brightness in Images of a Total Lunar Eclipse”
Clouds are moved by the wind. The average wind speed at the altitude of clouds is only about 18–70 km/h, relatively slow compared to the size of visible Earth’s surface from space.
Flat-Earthers use the lack of an apparent cloud movement to discredit videos taken from space. In reality, the clouds are moving far too slowly to appear moving in videos taken from space. To observe the cloud’s motion, we need to speed up the video.
Continue reading “Cloud Movements Seen From Space”
Flat-Earthers compared the apparent size of the ISS and an airplane that appeared in photographs and then incorrectly concluded that the ISS could not be 410 km above us. Their mistake was equating altitude with distance and failing to account for both the ISS’ and the airplane’s downrange distance.
If an airplane is at an altitude of 12 km, it does not mean its distance from an observer is also 12 km. Its altitude and distance are equal only if the airplane is directly above the observer. If the plane is not directly above, then its distance is greater than its altitude.
Continue reading “ISS Size Compared to an Airplane in a Photograph”