Lightnings taking a ride

by ceinmart

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visits member for 4 years, 11 months
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Jun
21
awarded  Nice Answer
Jun
19
awarded  software
Jun
18
comment What algorithm can I use to simulate bokeh?
Provided the operations are all additive you wont get the problem of dark areas spreading out. It's true you need a sharp mask to get sharp circles, but the major problem is that his bokeh operation is being applied to non-linear data.
Jun
18
revised What algorithm can I use to simulate bokeh?
added 874 characters in body
Jun
18
revised What algorithm can I use to simulate bokeh?
added 874 characters in body
Jun
18
revised What algorithm can I use to simulate bokeh?
added 874 characters in body
Jun
18
answered What algorithm can I use to simulate bokeh?
Jun
18
comment Why did manufactures stop including DOF scales on lenses?
@akram The problem is DOF scales on lenses just aren't very accurate, they are based on the assumption of a very small output size (this is where the dependance on megapixels comes in, with a higher resolution sensor you are more likely no notice if something is out of focus), they also require you to estimate the distance to objects in the scene for them to make any sense. They were better than nothing in the days of film, but now it's easy to check if something is actually in focus using the LCD.
Jun
17
revised Why did manufactures stop including DOF scales on lenses?
edited title
Jun
17
answered Why did manufactures stop including DOF scales on lenses?
Jun
15
answered How to photograph a tire tread without getting a bulge effect?
Jun
11
answered Should I remove the lens hood from lenses that I put in my bag?
Jun
11
answered Why do camera phones have lenses of inferior quality?
Jun
9
comment Is it possible to digitally capture a full 3D point of view?
@null You can make guesses, certainly, which is what that paper is doing, but that's not the same as having actual 3-d data. The correspondence between two images taken from different positions does contain 3D information.
Jun
9
comment What causes barrel distortion?
I don't have a time to do the full mathematical proof right now, but you do need a FOV of at least 180 degrees to see both vanishing points of two straight parallel lines.
Jun
8
comment Is it possible to digitally capture a full 3D point of view?
@null you can guess at depth, but that's it, there's no information there, from a technical standpoint. The best example of this is that it's impossible to tell the difference between a photograph of an object (that has depth), and a photograph of a photograph of an object (which has little-to-no depth). The reason you can't tell the difference is because there is insufficient information in the image.
Jun
8
answered Is it possible to digitally capture a full 3D point of view?
Jun
8
comment What causes barrel distortion?
I'm afraid this is wrong. Barrel distortion is not a consequence of trigonometry or perspective. It is a defect (or rather a compromise) in the design of a lens, there are lenses with zero (or as close as makes any difference) barrel distortion. Your example shows a FOV greater than 180 degrees, this is impossible without introducing some form of curvature, however every FOV less than 180 degrees can be achieved with zero barrel distortion or curvature of straight lines.
Jun
4
comment Why don't people care any more about shutter speed accuracy?
@DanWolfgang people obviously care when their camera stops working, the question is why don't they care when choosing a camera in the first place, there's nothing about shutter accuracy on the spec sheets etc.
Jun
4
awarded  Enlightened