Author Topic: New Raj shadow analysis  (Read 33725 times)

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Offline elevenaugust

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Re: New Raj shadow analysis
« Reply #15 on: December 22, 2008, 02:46:13 PM »
If I understand you correctly, then the key of the "dual source" is on the relative position of the subject/photographer/sun??

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Offline onthefence

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Re: New Raj shadow analysis
« Reply #16 on: December 22, 2008, 04:29:41 PM »
If I understand you correctly, then the key of the "dual source" is on the relative position of the subject/photographer/sun??
In the case of the cheerleaders, I think one light source can be identified because the exact point causing the shadow can be traced to an exact point that the shadow is cast. Also the fact that the surface ground is flat. but if you just go by the cast shadow on the ground and some possible part of their body then that path looks like it comes from multiple sources.

I am not seeing how this can help explain PICT16 though, it is just an interesting perspective trick.

Offline elevenaugust

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Re: New Raj shadow analysis
« Reply #17 on: December 23, 2008, 01:11:16 AM »
The ideal thing would be to find a photo with the same configuration as in Raj's picture.
I made some research in database, and the only that I found is this one:



Dunno if it could be useful....
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Offline nekitamo

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Re: New Raj shadow analysis
« Reply #18 on: December 23, 2008, 09:19:19 AM »
If ErrorLevelAnalyzer is to be trusted, this image is composite (plane was added):



But even without this tool, there's also problem with sharpness - note that closer wires are sharper than those further away, which places focal point in front of the pole? The airplane should be even more blurred, but it's obviously very clear and sharp (in the sunlight on a cloudy day?).

Offline elevenaugust

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Re: New Raj shadow analysis
« Reply #19 on: December 23, 2008, 11:09:28 AM »
Hi Neki!

Did you try ELA on the drones pictures; at the same threshold?

This picture, taken with a Canon EOS Digital Rebel Xti, is from Flickr's user CygnusX1, in the collection "transportation" and "Crop Duster" file.
Exiftool didn't show any trace of tampering with any soft, while JPEGSnoop said image is processed/edited... ???

I'm searching for a 'real' picture at approximately the same configuration as in Raj's pictures and showing useful shadows; i-e that can show apparent dual sun source.
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Offline nekitamo

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Re: New Raj shadow analysis
« Reply #20 on: December 23, 2008, 05:20:05 PM »
Hi Neki!

Did you try ELA on the drones pictures; at the same threshold?


Sure, I tried every treshold setting available, step by step... especially with pic16. ELA is not a conclusive method (even by far), but the result was always negative: w/o significant differences in error levels for any of the objects.

Also, there may be a second explanation for blur in your example image... perhaps it is a motion blur due to the photographer's matching of plane's motion with his camera at the moment of exposition? Hard to tell, as it is resized (resolution is not supported by the camera) and quality-degraded...

Offline elevenaugust

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Re: New Raj shadow analysis
« Reply #21 on: December 23, 2008, 06:16:43 PM »
I tried it too, exactly with the same process as yours, and no apparently JPEG errors so far.....

About my example, did you try the test with the original ones?? (The largest size)

I have found some other examples that I'll post in 2 hours when I'll be back home.

-----------------------------------
Another thing:
Quote
But there's something special about the DRT forum that is not so common elsewhere: it is a great place to do research, a place where you're treated with respect, a place where nobody is forcing you to think this way or that, despite what some may think. And let me assure you: there's no such thing some often refer to as "the DRT forum opinion" or "the DRT forum angle" or however they put it - everyone is allowed to think for themself over there. 
 

I forgot to thank you for these kind words that you posted last week on UCB.
Good to know we are among friends. :D
 
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Offline elevenaugust

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Offline nekitamo

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Re: New Raj shadow analysis
« Reply #23 on: December 24, 2008, 09:45:54 AM »
I forgot to thank you for these kind words that you posted last week on UCB.
Good to know we are among friends. :D

You're most welcome. And I really do feel like it here. :)

What I don't understand is the motivation behind some people's constant tries to prevent further research into this case by creating endless, meaningless (off-topic!) arguments and forcing others into accepting their conclusions by using whatever explanation seems handy at the moment. I mean, if they've concluded it is a hoax and not worth wasting time, why still discuss it? They seem desperate sometimes, resolving to insults, false accusations, character-smear campaigns and what not, just to achieve their goal. Why?

IMO, forums should work like this: you present the facts as you see them and let others draw their own conclusions about the subject - as simple as that. But when someone constantly revises his "facts" and pushes people around into accepting his conclusions - the only right thing to do is to ignore him. I believe exclusion of such people right from the start is another thing that makes this forum great - there's simply no other way to deal with them. But now I'm being off-topic... :)


I've checked your latest example images and also some of the others by the same author on flickr in ELA and can't find anything conclusively wrong about them - only the first example seems "fishy", but it could be a fluke. Now, back to shadow analysis...

Offline onthefence

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Re: New Raj shadow analysis
« Reply #24 on: December 24, 2008, 02:14:43 PM »
HPO, I'm not sure if you already tried this, but I see that nekitamo has put forth the point light source idea a few months ago. Can you (or did you) try placing a tiny bright lamp in the position shown below and photograph your model?



I am sorry it took me this long to catch up to all the analysis. I am now at the point where I can use a 3D program to experiment with simple shapes for myself, and I am having the same problems getting shadows to align as those before me.

Obviously a point light source in that same location does not make sense for each of Raj's images.

Offline nekitamo

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Re: New Raj shadow analysis
« Reply #25 on: December 24, 2008, 04:55:33 PM »
Here's another speculation: what if this point light source is sun, just outside of image frame? What happens with pole shadows in that case, do they still fit?

Note how image background brightens from left to right, could this be it? I still didn't finish this line of research...

Offline HPO

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Re: New Raj shadow analysis
« Reply #26 on: December 24, 2008, 05:14:16 PM »
HPO, I'm not sure if you already tried this, but I see that nekitamo has put forth the point light source idea a few months ago. Can you (or did you) try placing a tiny bright lamp in the position shown below and photograph your model?



I am sorry it took me this long to catch up to all the analysis. I am now at the point where I can use a 3D program to experiment with simple shapes for myself, and I am having the same problems getting shadows to align as those before me.

Obviously a point light source in that same location does not make sense for each of Raj's images.

Hi onthefence,

Yes I did try that, the picture I showed on page 1 has a point light.



This is the setup I used for that picture, and this is also the reason I think, why I can get this close to PICT016.
And yes your right, a point light doesn't make sense.

Cheers, and have a merry Christmas all  :)

Offline 10538

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Re: New Raj shadow analysis
« Reply #27 on: December 24, 2008, 05:16:11 PM »
I mean, if they've concluded it is a hoax and not worth wasting time, why still discuss it? They seem desperate sometimes, resolving to insults, false accusations, character-smear campaigns and what not, just to achieve their goal. Why?

Yep.  They do seem desparate.  I also wonder why.  Is it simply an ego thing?  To be right?
« Last Edit: December 24, 2008, 05:17:21 PM by 10538 »

Offline elevenaugust

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Re: New Raj shadow analysis
« Reply #28 on: December 24, 2008, 06:13:18 PM »

Cheers, and have a merry Christmas all  :)
Thanks, HPO.
Merry Christmas too and all of you.

Cheers
Tonio
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Offline 10538

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Re: New Raj shadow analysis
« Reply #29 on: December 24, 2008, 06:56:35 PM »
This is the setup I used for that picture, and this is also the reason I think, why I can get this close to PICT016.
And yes your right, a point light doesn't make sense.

Cheers, and have a merry Christmas all  :)

Move the light as far away from the subjects as possible.  That would more closely simulate the sun.

Merry Christmas