Fingerprints
Axial Lighting fingerprint: This photo was taken using a macro lens on a camera that was mounted on a quadrapod. The evidence item was a metal plate that had a fingerprint with a cyanoacrylate coating. The evidence item properties made it hard to use a straight on view of it. When examining the evidence item, the best visability of the fingerprint came from an angle that was inadequate for photography. The Axial Lighting technique, also known as bending light, was used to get a better view of the fingerprint while still being able to take a photo with the camera parallel to it. with the camera pointed down vertically, and the fingerprint on the metal parallel to it, a light was pointed horizontally at the midpoint between the evidence and camera lens. A clear glass was placed between the evidence and the lens in such a way that it would catch the light being pointed at the midpoint and create a similar effect to us looking at the fingerprint on the metal at an angle. With this technique we are able to achieve a clear photo of the fingerprint for comparison, there is also always a scale next to the fingerprint. ISO: 100 Aperture: f/22 Shutter Speed: 1/15 Sec.
Alternate Light Source Fingerprint: This photo was taken using a macro lens on a camera mounted to a quadrapod. The fingerprint was dye stained on a black energy drink can. It was unable to be seen by the naked eye but, with a light source with a nanometer wavelength of about 455 and a yellow filter (some prefer different nanometer length and different filters). For the best results using an alternate light source, it must be done in a dark room to get the most illumanation from the ALS. This photo was enhanced using photoshop to have better contrast between the fingerprint and the dark background. A scale is always used to show the size of the fingerprint for comparison. ISO: 100 Aperture: f/16
Shutter Speed: 30 Sec.
Black Powder Fingerprint on Clear Bottle: This photo was taken with a macro lens on a camera mounted on a quadrapod. This is a standard black powder photograph on a curved surface. The fingerprint is on the neck of a clear bottle which make it absolutely necessary to photgraph using a high f-stop in order to be able to get the detail from the center and sides of the print. When doing photography like this, it is important to take a photo of each side of the fingerprint if possible. The evidence was held in place by a clamp and lifted using scissor lifts to enable the best quality and clarity. The more light there is in the room, the easier it is to photograph at higher f/stops and lower ISO. I used bounce flash off of a white card in this photo to eliminate as much glare on the bottle as possible. ISO: 100 Aperture: f/22 Shutter Speed: 4 Sec.
Timed ExposureWith Filter: This photo was taken with a macro lens on a camera inverse mounted on a tripod. the fingerprint was placed close to the ground on a wall that was bright green, making it very difficult to see, even with black powder. The fingerprint needed to be photographed as is, then with a green filter on the camera lens to absorb the green light from the wall. We then switch the picture mode to Monochrome to get a black and white photo using the green filter and end up with a photo that shows a fingerprint clearly. The photo is then rotated to get a better view for compariso if needed. All photos have a scale to show it's size for comparisons. ISO: 100 Aperture: f/22
Shutter Speed: 13 Sec.
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