– Re: Photography
In Reply To
The second method for impressions on a mirror takes a bit of practice. It works easier with a camera tripod and/or an assistant to help hold things. You will also need a small sheet of glass and a flashlight.
First, use black powder on your impression. Next, set your camera up in front of the mirror. Standing behind the camera, hold the sheet of glass at a 45 degree angle between the camera lens and impression. The left edge of the glass will be closer to the mirror, while the right edge will be closer to the camera lens. From the right side, shine your flashlight onto the glass you are holding. This causes some light to be reflected down onto the mirror. If everything is set up right, the background will appear white and the impression will be black. No reflection.
For other reflective surfaces, it all comes down to controlling your light; both ambient and direct. You can use white shades to control glare. For windows you can hold a sheet of paper behind the glass. Conversely, shining a light from behind the window towards the camera can also work too.
One of the first options I would turn to if available would be a RUVIS (Reflected Ultraviolet Imaging System). Latent prints do not need powdering or chemical enhancement prior to this type of imaging. Most materials, including glass, absorb short wave UV light. This causes the background to appear dark and non-reflective. Only the fingerprint will be visible.