Evening

by w.hrybok

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5

AJ is correct here. What you are seeing is the result of motion blur as both the satellite and the aircraft are in motion relative to the ground (the desired target of the photo). Those pretty pictures you see in Google Earth and elsewhere are the result of red, green, and blue filtered images combined into what is called a "Multispectral" image (MSI), named ...


0

While there are application-specific names for what's going on (e.g. "moire") the fundamental cause is undersampling/aliasing. The original image has high-frequency content in it (tiny pixel boundaries) and, by using a wrong downscaling algorithm, you're point-sampling it with a lot fewer samples than what are necessary to reproduce the signal you're ...


2

To clarify what the people above said, the pattern you are seeing probably comes from photographing the gaps between pixels. For various reasons (e.g. camera tilt) they won't be perfectly aligned with the pixels on your CCD and in the resulting image. When downscaling, the algorithm has to decide what color will be a resulting pixel based on colors of ...


3

As other answers state, the effect is called Moire. But why does it happen when you downscale or zoom-out? As prevoiusly stated Moire happens when two patterns interact, specially if the two patterns have a "frequency" (read size of the repeating characteristic) close enough to each other. What happens next is a mathematic relationship between the patterns, ...


4

If the problem only happens when scaling, then that means the scaling is bad. A simple/low quality algorithm was used and therefore the scaled image looks differently than the original. With a quality scaling this does not happen. It would help if you would make the original image available. What software did you use to scale the image? For a quick check ...


9

As your existing (+1) answer says, it's a Moiré pattern. But you see it particularly when the image is scaled. You don't say what does the scaling, but I'm guessing you're just zooming the display, or pasting into Word/Powerpoint/etc., in which case you may benefit from scaling the image using a different method in the GIMP (free), Photoshop (expensive) or ...


38

This is moiré. It occurs because a screen is actually a grid of squares that are being used to make the image. When it ends up trying to be mapped to another grid of pixels (either by being captured by a sensor or by scaling) points of light or pixel data don't line up exactly. Some pixels get 2 pixels of information, some get the border between pixels. ...


2

This is something on or near the front of the lens. It is NOT dirt on the sensor. Normally I'd guess a water drop, but since it went away by itself in susbsequent photographs, it was probably a small insect that happened to be crawling around on your lens at the time, then flew off before you took other pictures.


0

Objects on the lens have to be fairly large and opaque before they start to show up like this in a photograph. Light from any particular point in the field of view strikes every part of the front of the lens and is then focused to a single point (hopefully) at the image sensor or film. Think about it: some telescopes have objects in the middle of the ...


0

It can be dust on the sensor or dust/water drop on the lens. First check your lens, is it clean? Then, make a photo of a bright gray area, using manual focus, completely **de**focused. Play with the focus length, I usually see this completely zoomed in (longest focal length). Then if you see the blur, it is a dust particle on the sensor. Clean the sensor. ...



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