High Speed Imaging of Small Objects
High speed imaging has become a standard tool for characterizing and quantifying high speed events. In most cases, the objects or events of interest are easily visible using standard optics.
However, there is an emergence of applications in Research & Development, Manufacturing and Inspection/Quality fields that require object magnification. When an object is magnified, its relative speed is magnified also. Example: applications that require magnification include nanotechnologies, cellular biology, droplet characterizations, fluidics and wire bonding. This is an abbreviated list of a long list of applications where the invisible can be made visible with the proper tools.
Optics required – Traditional Microscopes, Long Distance Microscopes
The amount of magnification varies by application. Some objects can be easily resolved with a commercial 105mm macro lens, while others require a high-power, traditional microscope. For applications that cannot be viewed by or placed under a traditional microscope, long-distance microscopes are used to observe small objects. There are many options in optics that are stationary and moderately portable that can be coupled to a high-speed imaging system to help capture events.
Lighting – Fluorescent objects, small apertures
The required optics adds another dimension of difficulty – reduced available light. High-speed imaging can be challenging in low light conditions due to the high shutter speeds required to stop motion. Combining already short exposure times with the aperture constrictions caused by microscope barrels, and optical relays within, can place strain in low light conditions. Additionally, some objects, such as living cells, are only visible when exposed to a certain wavelength of light which causes them to fluoresce. The low intensity of this fluorescence is difficult to record at normal video rates, and nearly impossible at higher frame rates.
Physical Size – Weight and balance
Many of today’s high performance, high speed cameras are large and heavy compared to “normal” CCD cameras used in microscope applications. With bodies up to 12” long, 4” – 6” wide and deep, and weights ranging from 12lbs – 15lbs., camera mounting can be a difficult proposition.
Phantom Cameras – The Solution
The Vision Research Phantom line of high-speed cameras is uniquely suited for these challenging applications. The cameras feature large pixel sites with high fill factors for unsurpassed light gathering ability not found in other CMOS based cameras.
Phantom high-speed cameras are highly sensitive as a result of large pixels and greater bit depth offering much wider latitude than off-the-shelf camera technology.
Phantom cameras possess a powerful feature leveraging the 12-bit sensors. The user has the ability to select an 8-bit subset of the full bit depth to display on the monitor. By adjusting the video output toward the bottom 8-bits, the user gains the equivalent of 10 f/stops of light without actually having to add additional illumination or introduce noise through the use of signal gain. This process is the equivalent of “pushing” ASA/ISO in the film world. While displaying the lower bits, the original 12-bits are retained in the recording preserving the full dynamic range.
For more challenging applications Phantom high-speed cameras can be combined with intensifiers and specialized lighting systems including lasers to help capture high speed events. In addition, cameras that extend the wavelength of light sensitivity above the visible range up to near infrared (1100nm) are also available.
The precise timing of the Phantom camera frame clock allows the use of synchronized lasers to create a high intensity light sheet to further illuminate hard to image particles free floating in space. This technique can be employed while using either standard optics or long-distance microscopes when objects cannot be confined to the viewing area of a traditional microscope.
The Phantom Miro family of high-speed cameras have a footprint not much larger than a modern point-and-shoot digital camera. At a mere 1.5lbs., the Miro easily replaces an existing standard frame rate CCD camera.
Small object imaging applications abound. With a combination of the right optics and lighting, combined with a matched high-speed camera, even the tiniest high-speed events can be imaged, recorded, analyzed, and quantified to fulfill any scientific or engineering need.
For more information about how a Phantom camera can meet your small object imaging needs, please contact your Vision Research sales representative.