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OSINT At Home #8 - Calculate time using shadows in a photo or video
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- Опубликовано: 28 фев 2021
- This tutorial is part 8 of the OSINT At Home series. It covers how to find out when an image or video was taken using shadows.
This is a form of verification and documentation referred to as 'chronolocation', and generally follows the process of geolocation. It is part of a useful skillset in image forensics.
Using the shadows in a photo or video can help us identify or verify when something was taken. Sometimes we either have no metadata in an image or a video, or we simply cannot rely upon it, so a way to either double-check the legitimacy of a timestamp, or to find a window of time, is by turning objects seen in imagery into a sundial.
We’ve all seen sundials, and have observed how they work, so digitally, any object can be turned into one, so long as we can see a shadow.
It should be noted that doing a shadow calculation is just one way to identify the time of when something was taken, and that there are a number of other ways such as looking at the metadata, using satellite imagery to identify buildings or objects present/not present in your image, or simply by observing signs in the image such as seasons, event-related items such as annual festivals, and others digital clues (also don’t forget to image reverse search for more context).
Why is identifying time of when an image or video was taken important? Geolocating footage is often standard practice in open source investigations to put a given item in a geographical place. But putting something on a chronological timeline is equally as important, it could be evidence in the leadup to an event, an alternative angle, or it could be old footage taken in a similar location as new footage - which would muddy your results or could be possible disinformation/misinformation.
Simply put, identifying the time of media allows for more scrutiny of facts and events.
The OSINT At Home series is useful for those looking to find digital breadcrumbs and pick up some methods of open source intelligence (OSINT), digital investigations and good old plain research. No matter who you are, or where you are in the world, you can follow these tutorials from home with publicly available information to answer questions such as who, what, where and when.
TOOLS
Suncalc (with coordinates and time): www.suncalc.org/#/51.5033,-0....
Google Maps: www.google.com/maps
Google Earth Pro: www.google.co.uk/earth/downlo...
Trigonometry calculator: www.carbidedepot.com/formulas-...
Google Image Reverse Search: www.google.com/imghp?hl=en
Yandex Image Reverse Search: yandex.com/images/
CASE STUDIES
BBC Africa Eye - Anatomy of a Killing: • Anatomy of a Killing -...
Forensic Architecture - Rafah - Shadow Analysis: • Rafah - Shadow Analysis
Bellingcat - An Execution in Hadrut: www.bellingcat.com/news/rest-...
MORE RESOURCES
Sector035 (AKA ‘Shadow Guy’) - Shadows and Suncalc: / lining-up-shadows
Nixintel - Digital Shadows: Seeking Sector035: nixintel.info/osint/digital-s...
Bellingcat - Using the Sun and the Shadows for Geolocation: www.bellingcat.com/resources/...
SUPPORT ME:
Please do consider supporting this content so I can create more and keep it free, independent and accessible to everyone in the world: ko-fi.com/bendobrown
MY SETUP:
Apple Macbook Pro 16-inch: amzn.to/3rTWhW3
Logitech MX Anywhere 2 mouse: amzn.to/3phQp7v
Blue Yeti USB microphone: amzn.to/3ajixmb
CREDITS FOR THIS TUTORIAL
Imagery: Google Earth/Landsat Copernicus
SunCalc.org ©Torsten Hoffmann 2015-2021
VOA News: www.voanews.com/covid-19-pand...
Music Intro: World’s Fair - God Mode
Music End: Dhaka by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 license. creativecommons.org/licenses/...
Source: incompetech.com/music/royalty-...
Artist: incompetech.com/
I think this is just amazing. I am not a journalist, and might never need to do stuff like this, but I just find it incredibly fascinating what information you can get out of a single picture.
Thank you 🙏
I think there is still much to learn about what we can do digitally, with just an image or a video. I hope that these videos encourage more open, public and transparent research in the field.
I am not good at computers but still subscribed for entertainment value ❤❤🎉❤❤❤🎉🎉❤❤❤❤❤
Finally, a use for Boris Johnson
lmfao
I have read some article about calculating time by shadow in pictures. This video is kind of piece of cake between them. Thanks a lot :) A great man said : If you cannot explain something in simple terms, you don't understand it.
I'm glad! I hope it helps in your work!
I recently found and have been binging your channel! Your tutorials are exactly what I have been needing ❤️
Thank you so much 🙏
Cool stuff. Things that are possible to do in a few minutes nowdays is crazy.
This probably was high level cia stuff needing mathematicians and astronomers 50 years ago.
Now anyone can do these things casually from their couch.
Amazing free hands on so many tools and appreciate this work. My question is, do we have tools to calculate heights of individuals from pictures or videos? Many Thanks
When I had to do something simular, I used Photoshop to measure distances in pixels. (In one case, it was the shadow a fence was making on road, and had no idea of actual height of fence). Measuring in pixels means you don't need actual heights as you are measuring ratios. The caveat: The length of shadow needs to be adjusted with trigonometry relative to a horizontal line on image so that you calculate length of a shadow that would be perpendicular to camera's orientation.
Another difficulty is determining where the shadow starts and ends. For a person height of top fo head against ground is relatively easy. But for more complex forms (like a fence) you need to make sure that you calculate distance of shadow on ground to right under the portion of fence that projects that specific shadow.
The other difficulty is determining where to end the lines where the image has "fuzzy" edges to the object and especially shadow. I think there is an "art" part of this science.
BTW, you have a fake location for Boris because Street View does NOT show a cat next to 10 Downing Street :-) If I turn off 3D imagery, then I have to go back to 2014 to see a haf decent image, and even that one doesn't have enough details to see door , even less the corner. (so this means that you need the 3D imagery to see images of streets taken from the airplanes with stereo cameras that Google uses to create 3D imagery).
Thanks for saying this - and a good idea on pixels. I was going to ask how to adjust calculation if image is on a slope, as that will alter the result (the shdow would be longer on a decline/shoter on against a rise).
Great analysises! Enjoyed the video so much! Thanks, Ben!
Glad you enjoyed it!
This is proof you should study trigonometry in school.
Tried suncalc at my location, it was like 30-40% off for total daylight time... it said I should have 12 hours, actually have 16.
With the 1.46 m shadow length you said, we end up with a photo taken between 11:12 and 11:14 am.
Great video, thanks !
Thank you 🙏
Follow up video idea.. If you knew where and when the photo was taken like through exif data or something, could you extrapolate the subjects height if it wasn't already known.
Thanks for the suggestion - I'll add it to the list. I've got another shadow piece I am working on that should come out within the next month on human-rights based investigations.
I am an huge fan man. Please can you guive us some tips about how to masterisy this skill like you did in your videos.
You can watch my ‘let’s geolocate tutorials’ and my other osint at home videos to practice these steps. I also regularly post these things on Twitter/X at Bendobrown, and I always cite the source so you can try to follow along with the geolocations/verifications
@@Bendobrown Amazing man can you share with us your other social medias please.
@@Bendobrown We are living dangerous times we need more peoples like you. Your content needs to be suported.
Great explanation
Glad it was helpful!
it's prolly safe to say when this photo was taken there was a party on in the building behind which Boris had to get back to 🎂
😅
Brilliant!
Is this technique works the other way? I mean by knowing the time and measuring shadows can we guess the location?
unbelievable!
Nice video thanks!
Glad you liked it!
Surely there are easier ways of finding line B? Using Google maps like that is v. limited (was there Google Maps coverage in the Cameroon case study? Doubtful). Wouldn't it be simpler, and more accurate, if you just used the confirmed height line of Boris and compared the line B to that? There must be a tool online to work out the percentage of one line against another? Thanks.
Hi Ben thank you for another video. In regards to figuring out the height of a object how would you go about with unknown objects like trees or buildings? We could easily obtain Boris Johnson's height from the Wikipedia but what if the object is unknown to us
Hi Richard. This is a really good question. I'm going to create another video showing this.
To answer your question, if I did not know either the height of Boris, or the length of the shadow, I would use this tool: www.rapidtables.com/web/tools/pixel-ruler.html.
How? It measures pixels on the screen.
So height of boris: X pixels
Length of shadow: Y pixels
And then with those two variables we can get the altitude (trigonometry calculator)
And if we've geolocated the image, we can get the azimuth.
With all of those, we can then use the pixels in suncalc and perform the exact same process as seen in this video.
Hope that helps!
@@Bendobrown Amazing. Thank you again
But what if the shadows are not perpendicular to the camera? Boris’ shadow is angled away so simple two dimensional trigonometry would not cut it, right?
Really nice...
Thank you Shantanu!
Very interesting. Congrats! Is it possible to measure the heigth of a person or an object in an image?
Sure is. Depends on the case though. Could be that they're standing next to an object that has a known height, say for example a specific model of car? For the shadow ones, I always measure in cm on my screen, as the shadow calculation really only matters for the variables of angles, not the value on the measurement units.
@@Bendobrown okay. Thanks a lot
@@SgtEnilson to get a rough estimate you can use average heights of people as a starting point. This is done with rifle ballistics all the time where the average height of a man is very roughly 5'9.
OK SPACE MAN !Son I belive he's a Wzaarrd Wizardoooo Math me a something
When you calculated b. the shadow length? ... would the far end of the shadow that is at the step not be the shadow of his head? Therefore the line you have drawn should actually be the hypotenuse? or ... is sky calc automagically taking that into account?
Hi Stuart. In terms of the trigonometry labels I would refer to the 'shadow length' as that of which is on the ground as a measurable variable.
Here is a calculator that's more relevant to shadow calculations than the simple trigonometry calculator I used in the video: rechneronline.de/sehwinkel/shadow-casting.php. You can see the table of variables much more clearly in here in order to calculate the altitude of the sun.
Sun calc uses all four variables. But the two in relevance here is the object height, and the 'length' of the shadow. That's measured by the 'length' of the shadow that we can see on the ground.
I hope that helps?
Hi. What image editor are you using to annotate?
I use preview, on a mac. You can use Markup, Paint, or Gimp on a Windows (free) if you're on that!
@@Bendobrown great. Thanks
How to calculate speed, like some videos that shows an UFO or something.
You need to know the distance travelled and the time it took to travel that distance. Then you will have the speed.
Brother i am afraid what if this kind of knowledge gets into wrong hands ? 😢
ill come back later this is too much math right now.
still can't find Biden even with OSINT.
「動画の音が良くない」、
up the boris