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infrared camera for the forensic purpose

Friday, September 20, 2013









One request from my reader , to make a review of my infrared camera in  forensic photography after reading my article camera for detecting counterfeit money.

So here is my review, I took my casio QVR300 modified to full spectrum and attach infrared filter on it. The normal images taken with canon 1000D.

The forensic test should be bloodstain but I don’t want to hurt anything, and I don’t have any access to forensic evident  so I replace the blood with dark black inject refill ink. My asumtion is while blood is red, but it denser than ink, so it should be create more clear result.

I splat the ink so small so it absorb in my black fabric completely, with naked is imposible to see where the ink is fall , you can see it on this normal images





I wrote on black part on this bag , wih black ink. feel like writing with transparent ink. you cant see what you write.

its all clear in infrared.



stain on dark blue jersey

infrared  image on dark blue jersey


stain on complicated pattern


in infrared we can see even the smallest stain


very small stain on bright red fabric


still can be captured in infrared

By the infrared camera, it so clear where it was. This can be use for tracing any stain on fabric. Ink, blood , dirt  , anything that not came originally from the  fabric can easily found in this method.

Falsefiying letter
Imagine if somebody cover on some information on letter, and you want to see the printed below. See the original image



infrared will reveal it

See the infrared image
( warning not every ink will disappear in infrared) ballpoint an pen should be disappear, but gel are not. Permanent ink can be penetrated if it not too dense.


  Again , the counterfeit money

  This image base on my assumption , different ink have different effect in reflecting infrared.
Under my assumption, it will make difficult if we cover the information with same ink. will have same effect and  make our work worthless

But in this case, is had big possibility than the one who cover  the text is the one who write and and he did it at almost same time.

Falsfaying number
Modified number is common practice, change 1 to 7 , 0 to 6 or 8 or add 1 digit . lets see what infrared can do

I put 1 in front of 33 so it read as 133



in infrared due I use different pen ( gel pen) it will  show the extra 1 while other are disappear


I modified 1 into 4 should be Rp 120.000 and become Rp 420.000 

 
this using same ink so its little hard to know do it falsifying or not

 but in big image, actually it easy to reveal

Doubled ink will make denser, so it will trace in infrared easily


FAQ

Q: What gear should  we need to make this images?
A:  infrared camera and desk lamp
Q: What if I go to crime scene and of course I won’t carry desk lamp?
A: You can use a flash light with strong lamp, as example flash light with CREE Led, its not expensive, mine is less than $5. and it work ok, only have small coverage, here is the sample.
You will find this even easier to handle in some condition, which you cant carry the evident to your lab. the lamp  just used to guide the autofocus, the biggest light came from its internal flash 

Q: What if I use infrared DSLR, why you don’t use infrared DSLR ?

A: I don’t like dslr , its expensive, its bulky , and not live view ( some dslr already have live view but if you like live view why bother buy dslr, just buy mirrorless instead) and the worst thing it cant focus closer enough if you use kit lens. Pocket are born to master in macro , while dslr you had to buy macro lens. Mean extra money. Of couse regarding the result, DSLR have better image quality, but it also cost you a lot.

Q: Where can I get this pocket infrared?
A: You can convert itself, you can buy it in somebody who can convert it to infrared, or, of course you can buy it from me.  He he he





   

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