Photography Using an Alternate Light Source

“WYSIWG”

The simplest and most important rule for photographing evidence with an FLS is “What You See is What You Get”.  However you see the evidence is exactly as the camera should see it.

If you visualize the evidence illuminating with 445nm and are wearing the Orange Goggle, to document with imagery you do exactly the same thing; illuminate with 455nm and place an Orange Camera filter on your camera, ideally Orange #21 to match most Orange Goggles.

Some individuals try to save time and money by taking WYSIWYG too far, that is to say they will shoot the image through exactly the same goggles they were wearing during examination.  On the surface this seems logical however, the goggles used with almost all forensic light sources are plastic and not indexed.  They are not uniform.  They are uniform enough for our eyes to see the evidence well enough but the camera is not as forgiving as our eyes.  The camera filters provided by your forensic light source manufacturer are indexed and reproducible.  That means someone using a Mini-CrimeScope illuminating at 455nm photographing something using the Orange #21 filter is going to see the same thing anyone else who is using that same combination.

Select the proper filter

There are 3 main types of Camera Filters; colored plastic, Colored glass., and bandpass Interference.

Colored Plastic are Low Performance, but convenient for fast evaluation and Low Cost.  Colored Glass provides Medium Performance and are Low Cost.   Bandpass Interference filters are the ultimate providing Very High Performance / contrast but come with a High Cost.

Turn off your Camera's flash

If your camera has an integrated flash, make sure it is turned off.  Forensic light source photography is essentially low light level photography.  Your camera is going to have to try to capture the very weak fluorescence.  Just like it is suggested to darken the room as much as possible when doing the examination, you need to darken the environment and TURN OFF THE FLASH.  Using a flash will end up giving you brightly colored images in the color of the camera filter you put on the front of the camera.

Follow this link for some Tips and Tricks to FLS Photography