BTDF-I Coaxial reflection mirror (Stretchable shading cylinder)

Purpose

Used to photograph fingerprints on horizontal light-colored smooth surface.

Content

Description

Working principle

A. After the light from the light source is reflected by the half mirror, it irradiates vertically downwards on the smooth surface of the object along the optical axis of the camera lens.

B. The background reflects the incident light vertically upwards, then all the reflected light is in the direction of directional reflection, so is all the energy.

C. The fingerprint diffusely reflects the incident light, then the reflected light is in all directions, so is the energy.

D. When viewed in the vertical direction, all the light reflected by the background enters the lens, and only a small part of fingerprint-reflected light enters the lens. The result seen through the lens is the dark fingerprint in a bright background.

E. The lens hood prevents stray light interference from the environment.

Photograph fingerprints on horizontal smooth surface.

A. Mount the camera on the imaging system, macro lens on DSLR camera, directional mirror on macro lens (connect lenses of various calibers with conversion adapter), then mount the lens hood on the directional mirror.

B. Place the fingerprint under the lens hood, which can stretch downwards automatically. Shelter the fingerprint with the lens hood to block stray light interference.

C. At a distance of about 1m, illuminate the half mirror of the directional mirror with the light source pad. The light source pad is the same height as the half mirror. The light from the light source pad, after reflected by the half mirror vertically downwards, irradiates the fingerprint. Then, the light reflected by the background vertically upwards enters the lens through the half mirror.

D. Adjust the height of the camera, the height and position of the light source pad, and the focal length of the lens until the dark fingerprint on the bright background can be seen clearly in the lens, then photograph the fingerprint.

Product Application

Application areas for our products include crime scene investigation, fingerprint collection and development, footprint collection and development, tool marks collection, trace evidence collection, documents examination, forensic medical examination, forensic evidence collection, DNA collection, DNA disinfection, criminal photography, criminal investigation light source, narcotic drugs test, poison test, evidence packaging, evidence marking, crime scene plotting, crime scene protection, human body protection on crime scene.

Our Service

We can provide reliable product and service for you.

1. Q: Is it a reliable company?

A: Beijing Bulant Police Equipment Co.,Ltd. is a company specialized in forensic product, such as: crime scene investigation, trace detection, fingerprint development and extraction, footprint extraction, micro-evidence extraction, files & documents inspection, gunshots detection, forensic examine, DNA extraction, criminal photograph, forensic light source, alcohol test, traffic scene investigation, drug & poison examine, evidence packaging, consumables in lab, etc.

2. Q: What about the delivery?

A: We can offer the door to door services by air or by sea just depend on your actual request. Such as DHL, UPS, TNT, FEDEX…

3. Q: What is the package?

A: Aluminum alloy case/carton case/wooden case.

4. Q: Do you have any timely technology supports?

A: We have a professional technology supporting team for your timely services. We prepare the technical documents for you, also you can contact us by telephone, webcam, online chat (google talk, MSN, skype, yahoo).

5. Q: What is the payment method?

A: T/T, WESTERN UNION, MONEY GRAM, ESCROW, PAYPAL

6. Q: Do you take part in the world exhibition every year?

A: Yes, we took part in exhibitions every year since 2008.

Langfang Danmei security equipment Co., Ltd.established in 2012, 15 February, with registered capital of 22 million yuan, is located at Langfang City, Hebei Province. The company possesses four buildings, including production workshop, finished product warehouse, material warehouse and scientific research building, total area is 8934 square meters.

The company focus on development and manufacture criminal investigation equipment. We have a research and development team which has a full range of technical talents, including forensic science, machine design, machining, electronic circuit design, optical design, automatic control and chemical analysis.

After years of research and development, we have established a relatively complete criminal investigation equipment product system. The products application area includes fingerprint collection and examination, footprint collection and examination, tool marks collection, trace evidence collection, document examination, cartridge marks collection，forensic medical examination, forensic evidence collection, DNA collection, DNA disinfection, criminal photography, criminal investigation light source, narcotic drugs test, poison test, evidence packaging, evidence marking, crime scene plotting, crime scene protection, human body protection on crime scene.