| Author | Message | ||
     Don joe (Don_joe) Member Username: Don_joe Post Number: 4 Registered: 05-2011 |
Actually it needs to see with the help of visual aids because it has light refraction. | ||
| O P Jasuja (Unregistered Guest) Unregistered guest Posted From: 117.211.85.130 |
I am sure by this time you are aware of this research work, Jasuja OP, Singh GD, Sodhi GS: Development of latent fingerprints on compact disc and its effect on subsequent data recovery. Forensic Sci Int; 2006 Jan 27;156(2-3):237-41 PMID: 16216458 | ||
| thebox |
Hi, I was woundering if you can lift a fingerprint from a DVD and not harm the DVD. I can see the print very well. The print is on the side that needs to be read by the DVD player | ||
| Kasey |
Mark, Unfortunately, the repeatability you seek is not as cut-and-dried as you might think because of the differences in the type of substance on the finger. A surface might act differently with one matrix than with another. Additionally, surfaces which may appear similar in fact have completely different properties and therefore would dissipate or reflect light differently at the matrix/surface interface. Latent print examiners use general principles when deciding what technique to use in developing prints on surfaces. The general rule of thumb is that if the surface is non-porous enough to bead water, then it is processed with a different set of techniques than a porous surface that would absorb water. Of course, there is a continuum of surfaces in this regard, including glossy paper and many plastics. Sorry there are no absolutes on this topic. I wish you well with your further research. -Kasey | ||
| Mark Lego |
Thanks for the response, however i am still looking for more informations. For instance, Chrome or stainless steel seem to leave fingerprints no matter what the oil amount on your fingers or angle that you look at the metal. I was assuming gloss level or the polish of the metal, However some stainless steel do not have a high gloss level and still leave a smudge or print. I guess i am looking for some kind of repeatability in fingerprints. Ex. "You will get a visible print on This and not this because of this" Thank you, | ||
| Kasey |
Mark, You are very perceptive. The reason you can see latent prints on some surfaces has everything in the world to do with light interacting differently with the properties of the surface/substance combination than just the surface. Some plastics reflect light well, and therefore the prints are easily visible. Another facet to plastic is that some types of plastic absorb or dissipate the substance, therefore nothing is left to visualize except a "blob" of moisture/oils. Hope this helps with your journey for knowledge. -Kasey | ||
| Mark Lego |
I am trying to understand why on some surfaces fingerprints can be seen without any visual aids. This occurs to me, on high polished metals, stainless steel etc. Does it have somthing to do with light refraction off the metal through the oil? If it does why are they visbile on some plastics as well. thank you your assistance |
