Search results

There could be other reasons for objects sticking to the vaccination site: a) if a Band-Aid or similar item was put on the arm, when this is removed there may still be some residual adhesive on the skin. b) the injection site may have exuded blood, serum, pus, etc. This might be sticky...

In #40 I mentioned that I had taken photos of a sphere (a tennis ball) showing perspective distortion near the edges of the photo, even with a standard lens. For the record, there are some examples below. The first three photos were taken with a Samsung Galaxy 10A phone camera. The second two...

Looking through this discussion again, I think for the record I should correct or amplify something I said in #17: I was tacitly assuming that the objects are more-or-less in the same direction of view. For this case I think the statement is broadly correct, but for other cases it may well be...

I don't think there is any agreed definition of the term 'distortion'. Some people use it narrowly to cover only images which are inconsistent with linear perspective, notably where straight lines in the real scene are represented by curved lines in the image, as in 'barrel distortion'. Others...

Thanks! (to you and Jarlrmai) That is the kind of clarification I was looking for. If the wide-angle lens does 'stretch' the edges of the image, that would help explain the big Bidens. I remember reading somewhere that even a pinhole camera, with no lens at all, can have some surprising...

Various further news reports have tried to explain the picture, like this video from Inside Edition: Source: https://www.youtube.com/watch?v=-JDmnYWEniE Most of these accounts emphasise the use of a wide or ultra-wide angle lens or setting to explain the apparent distortion. For example...

I'm sorry to be a nag on this point, but news sources seem to be running away with the idea that the Biden picture oddity is an artifact of the wide angle lens, and I'm not sure that is correct. It isn't necessary to use a wide angle lens to get a foreshortening effect: see for example the...

In the video, Mick puts some emphasis on the use of a wide angle lens, and various news reports also stress this. In the above, however, the stress is put on the effect of perspective, and not the lens. I'm not clear whether the type of lens used actually makes any difference, except in so far...

Having seen the blown-up photos in Jarlmai's #96 above, I accept that I previously underestimated the full width of the object, from tip to tip of the 'wings'. It is very difficult to identify the tips without zooming in closely, and I couldn't zoom in far without cutting off part of the full...

I based my 1/200 figure on a) my own measurement of the image on screen, and b) Jarlmai's comment at #39 above, saying he measured the object at 20 pixels, which makes 1/200 of 4000(ish). If it is 30 pixels that obviously has a proportionate effect on the result. But I'm not clear where you...

Sorry, I overlooked that you revised your distance estimates. In an earlier post you gave a range of 203 to 336 meters, which is what I had in mind when I said my estimate was only half your lower end. You did indeed later reduce it to 137 meters. No-one so far has shown an error in my method...

I have gone back to basics again to make my own estimate of the distance of the object in the second photo. Unless otherwise stated, distances are given in meters, and angles in degrees. I assume that the jet is moving in a straight line and the object is static. Construction: Draw a line...

I wouldn't exactly dispute your conclusions, because I don't understand either cameras or geometry well enough to follow your calculations. As the metadata about the photo seemed to exclude the use of zoom, I reapplied my own crude method, using 65.5 degrees as the FoV, and got results very...

I think you may have overlooked the word 'if' in my comment: I don't myself believe it is the real shape of the object, but some people do, so it is worth considering the implications of that.

I wondered what airplanes would look like in night vision without bokeh. Browsing on YouTube I didn't find many suitable examples, but this one may be relevant. It shows a plane passing overhead, apparently at quite low altitude, through a Yukon Night Vision scope. (I couldn't find any...

I know next to nothing about cameras, but surely the fov depends on the zoom factor, if any? If I understand correctly, the iPhone 8 has an optical zoom of x2 (by switching to a different lens) and a digital zoom of up to x10.

What image are you referring to? An iPhone 8 camera screen is said to have a standard pixel count of 1334 x 750, giving a h:w or w:h ratio of about 1:1.78. Presumably if it is redisplayed in some other format the pixel count might change, but the ratio should not, if the only change is a...

I tried my own primitive method of calculating the size of the object, given an estimated distance of 300m and a guess at the camera field of view. If the fov is 30 degrees (which assumes it is moderately zoomed, taking into account the blurring of nearby objects), the width of the fov at a...

Gtoffo: If you are correct about the size of the object (which I think depends crucially on the field of view), we can also rule out a manned alien spacecraft, unless the aliens are really tiny. Perhaps 'manned' is the wrong word. Should it be 'alienated'??

Just to be clear, have the Navy officially codenamed this 'Acorn'? That is the claim in the 'Mystery Wire' video, but I wanted to check. When I first saw this mentioned I assumed it was something new, but it is evidently just the Batman balloon filmed a moment earlier. I've seen some oddly...