Full Spectrum Imaging System FSIS-II Backpack

Key features

• Provided with a set of LED lights for visible evidence detection and fluorescence
• Plus UV-C illumination for detection of latent fingermarks.
• The in-built unique FSIS-II integration features extends imaging capabilities across a broad range of surfaces including the ability to capture ridge detail on curved surfaces, eliminating the potential for errors caused by photo-stitching processes.
• High Dynamic Range (HDR) – Allows a single image to show detail in both dark and bright areas, verses needing to choose to expose for one or the other.  retain ridge detail in brighter parts of the image, while simultaneously revealing parts of the image that would have previously been too dark to see.
• Background removal – with shortwave UV backgrounds are removed effortlessly.
• Non-destructive way to analyse almost any piece of evidence.  This includes metals, plastics paper and even food items.
• Provided in backpack with tripod

Why the use of 254nm UV-C within this system?

Simply the answer to this question is that you reveal marks you haven’t previously been able to detect with traditional techniques.

Extensive validation work has been undertaken on this technique which is showing significant mark detection improvements compared to visible and chemical treatment in the UV-C 254nm region.

• Strong absorption – fatty and amino acids exhibit strong absorption at 254nm
  • Tyrosine
  • Tryptophan
• Contrast mechanism
  • Replies on reflection or absorption
    • Non-porous = Reflection
    • Porous = Absorption
  • Optimal Wavelength
    • Studies have indicated that the UV-C of 254nm is the most effective wavelength for detection of latent fingermarks compared to longer UV wavelengths like UV-A (365nm)
  • Equipment availability

Are all UV-C wavelengths alike?

• 254nm mercury vapour lamps are narrow bandwidth with (+/-) 1nm light bleed
  • Able to create more contrast due to minimal bleed interfering with the filter
  • Superior to LED lamps (see below)
  • 254nm is further away from visible light
    • Dropping more backgrounds on substrates
    • 254 can’t penetrate glass and most plastics, allowing easier imaging, whereas longer wavelengths penetrate causing confusing backgrounds.
• LED lamps have a much wider bandwidth with approximately (+/-) 20nm light bleed
• • • • This produces significantly less contrast due to the larger cone of interfering bleed with the filter
      • Examples of this are LED lights available in longer wavelengths such as 262nm, 280nm, 365nm