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Two photographers captured the same millisecond in time (2018)

dpreview.com

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Re: Two photographers captured the same millisecond in time (2018)

#41

Post by ipython »

SpaceNugget wrote: post #40
ipython wrote: post #35

Earlier quoted context omitted.

Think of it this way: you run a website that displays photos in chronological order. You receive these two photos. Which picture was taken first? How can you tell?

That's not an example of a distributed system, so it doesn't really clear up whatever the GP was trying to say about time in distributed systems at small scales. But even if it was this is nonsensical. The visual content of a photo is generally not what is used to determine the moment in time when it was captured. There's metadata in the image format that specifies when the photo was taken. There are pictures taken a…

The distributed part is the clocks on the cameras across the world. The article discusses the timestamp is included in the exif data embedded in the jpeg file.

The clocks are most likely synchronized based on gps assuming they’re already pulling location data from the satellites, the time is “free”. However, the precision of the clocks is not specified and like any process is subject to error. So at the small timeframes here (sub millisecond), you are potentially within the margin of error. When the error bars of several measurements from distributed parts of your system overlap, how do you determine an ordering between them?

Re: Two photographers captured the same millisecond in time (2018)

#42

Post by thih9 »

mherdeg wrote: post #23

(I realize that there are a few details that you can use to tell these apart, but,) Who gets to register the copyright on the image?

There would be two copyright holders, one for each image.

Even if they left the lens caps on and both images were black on black, there would be two distinguishable images with e.g.: different exif data, sensor noise, etc.

Re: Two photographers captured the same millisecond in time (2018)

#43

Post by Fatnino »

pimlottc wrote: post #38
mrb wrote: post #34

I cropped the pictures, and rotated Ron's picture by 0.2° (it wasn't perfectly vertical), so as to line them up on the lighthouse's door: https://i.imgur.com/ISIGQrR.png https://i.imgur.com/qLtZprZ.jpeg Open both in 2 tabs on a computer, and quickly alternate between the 2 tabs, the 3D effect is quite visible because of the perspective differential :-)

Works well with cross-eyed viewing too, with the images side-by-side: https://jsfiddle.net/pimlottc/f1saz46m/1/show

This doesn't work on mobile because jsfiddle has that little overlay in the top corner covering most of the picture

Re: Two photographers captured the same millisecond in time (2018)

#44

Post by pimlottc »

Fatnino wrote: post #43
pimlottc wrote: post #38

Earlier quoted context omitted.

Works well with cross-eyed viewing too, with the images side-by-side: https://jsfiddle.net/pimlottc/f1saz46m/1/show

This doesn't work on mobile because jsfiddle has that little overlay in the top corner covering most of the picture

It's not so bad in landscape mode for me, try that perhaps?

Re: Two photographers captured the same millisecond in time (2018)

#45

Post by xattt »

Phemist wrote: post #12
dogman1050 wrote: post #9

This is great! When I look at each picture with one eye simultaneously, I see the image in 3d.

And the author's name, for me, read as Eron Grisman

Some say… you can measure his position or his speed, but not simultaneously.

Re: Two photographers captured the same millisecond in time (2018)

#46

Post by ern »

Fatnino wrote: post #43
pimlottc wrote: post #38

Earlier quoted context omitted.

Works well with cross-eyed viewing too, with the images side-by-side: https://jsfiddle.net/pimlottc/f1saz46m/1/show

This doesn't work on mobile because jsfiddle has that little overlay in the top corner covering most of the picture

You can delete the overlay using dev tools.

In Chrome, I hit F12, selected the overlay in the DOM and deleted it.

Re: Two photographers captured the same millisecond in time (2018)

#47

Post by margalabargala »

ern wrote: post #46
Fatnino wrote: post #43

Earlier quoted context omitted.

This doesn't work on mobile because jsfiddle has that little overlay in the top corner covering most of the picture

You can delete the overlay using dev tools. In Chrome, I hit F12, selected the overlay in the DOM and deleted it.

I doubt the person you replied to has F12 available on their mobile device.

Re: Two photographers captured the same millisecond in time (2018)

#48

Post by alasarmas »

margalabargala wrote: post #47
ern wrote: post #46

Earlier quoted context omitted.

You can delete the overlay using dev tools. In Chrome, I hit F12, selected the overlay in the DOM and deleted it.

I doubt the person you replied to has F12 available on their mobile device.

javascript:(function%20()%20%7B%20%20%20%20var%20i,%20elements%20=%20document.querySelectorAll('body%20*');%20%20%20%20for%20(i%20=%200;%20i%20%3C%20elements.length;%20i++)%20%7B%20%20%20%20%20if%20(getComputedStyle(elements%5Bi%5D).position%20===%20'fixed')%20%7B%20%20%20%20%20%20%20elements%5Bi%5D.parentNode.removeChild(elements%5Bi%5D);%20%20%20%20%20%7D%20%20%20%7D%20%7D)();

Re: Two photographers captured the same millisecond in time (2018)

#49

Post by throwaway290 »

mherdeg wrote: post #23

(I realize that there are a few details that you can use to tell these apart, but,) Who gets to register the copyright on the image?

The scene is not subject to copyright (naturally occurring).

If we pretend that camera sensor captures are exactly the same, then I guess it does not belong to a single photographer in this case. But usually no one cares about sensor data, people care about "deliverables", like JPEGs or printed versions, and they will not be the same because everything after sensor capture would be different for each photographer.

Re: Two photographers captured the same millisecond in time (2018)

#50

Post by mmoskal »

bean-weevil wrote: post #32

I'm surprised that the exif data was accurate to the millisecond. Quartz clocks won't typically maintain that precision over the course of a single day.

If the water is moving at 10m/s and you can spot 0.1m difference in the photo then it would need to be within 10ms of each other.
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