PHOTON FAQ - CAMERA CONFIGURATION
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1. What is included with a Photon delivery?

This depends on what is ordered. The Photon OEM camera core by itself is positioned as a high-volume thermal imaging component that customers integrate into products or systems of their own design. Most OEM customers interface directly to the Photon’s 30-pin electrical connector for power (in), video (out), and other select functions. This connector also facilitates camera control and serial digital data if needed. Therefore the Photon core by itself is typically what is ordered by and delivered to OEM customers.

For evaluation purposes, FLIR offers an optional OEM Accessory Kit that enables customers to operate a Photon until such time as they develop their own interface. This Kit contains a power supply, break-out box (called an I/O Module), an interface cable to the Photon, and a small adapter circuit (called a wearsaver) that attaches between the camera connector and the interface cable. A rear cover is also supplied that encloses the wearsaver adapter and allows for secure attachment to the interface cable. It is the customer’s responsibility to provide a video cable and monitor, and an RS-232 cable if remote control of the Photon is desired.

A picture of a Photon with accessory kit items can be seen here.

A Photon camera control software program (GUI) is available for download here.

The accessory kit part number is 421-0021-00. The kit includes the following items, which may also be ordered individually:

320 and 160 Accessory Kit

421-0021-00 is the part number for an Accessory Kit compatible with both the Photon 320 and Photon 160 cameras. This Accessory Kit includes the following items:

640 Accessory Kit

421-0030-00 is the part number for an Accessory Kit compatible with the Photon 640 camera. This Accessory Kit includes the following items:
333-0005-00
I/O Module
206-0001-20
AC/DC Power Supply
208-0004-02
Line Cord
308-0076-00
Interface Cable
250-0194-00
Wearsaver Connector2
261-1273-00
Wearsaver Cover2
333-0018-00
I/O Module1
206-0001-20
AC/DC Power Supply
208-0004-02
Line Cord
308-0144-02
Interface Cable
421-0028-00
Wearsaver Adapter/EMI Cover Kit2

1 Backward compatible with Photon 320,160,etc.
2 Required for compatibility with the Ethernet Module


2. Can lenses be interchanged on the Photon? What if I want to use a different lens? Will FLIR calibrate my lens with a Photon?

We advise against customers changing Photon lenses without first understanding the implications and consequences. Each Photon is calibrated with its associated lens at the factory. The calibration data is stored in camera memory, but there is only enough memory to support a single lens. It is physically possible to change lenses, however, if a different lens is installed, the original calibration is no longer valid. If a Photon lens is changed without recalibrating the camera, it will work but the image performance will likely be degraded. In addition, several of the available lenses use different adapters to attach to the Photon camera body, so changing lenses often requires a different lens mount. Use of a third-party lens would require a custom lens mount, as well as knowledge of the back working distance to ensure lens focus from infinity down to the minimum distance capable with the lens focus system. The design of lens mounts is critical, as a poorly designed mount may introduce unacceptable image artifacts. As a result, FLIR cannot be responsible for the performance of third-party optics used with Photon cameras, nor can FLIR provide optical design information or support for other than the existing Photon lens mounts. Finally, changing lenses can only be done by disassembling the Photon, and the warranty will be voided if this done by a customer.

For qualified customers that furnish their own optics for use with Photon cores, FLIR sells a Windows(TM) application program called Alt Lens Cal. This software allows users to perform a supplementary calibration of the camera with a lens. This field-calibration process requires the use of at least one blackbody source (a highly uniform, controllable temperature reference) that has an area greater than the diameter of the front of the lens. It also requires a customer-furnished PC, which should be dedicated to this task. The calibration routine calculates gain terms on a per-pixel basis with the customer-supplied lens attached to the Photon core, and stores the customer-performed calibration in non-volatile camera memory. The original factory calibration coefficients are first uploaded from the camera and stored into a file on the PC, then the new calibration data is downloaded and stored directly into the camera. Multiple calibration files can be stored on the host computer.  The original factory calibration file can be restored if necessary, and the customer can actually build a library of lens calibration files for a Photon camera.

The current version of ALC software is part number 110-0106-72, and supports all versions of Photon cameras delivered beginning in 2008. Contact FLIR for ALC software for Photon cameras delivered prior to 2008.
3. What are the lens options and the minimum focus lengths for the Photon? What is the range of focus? Is it possible to adjust the focus of Photon lenses manually?

Focal Length 6.3mm 14.25mm 19mm 35mm 50mm
f/number 1.2 1.3 1.4 1.4 1.7
Field of View1          
320x240 - 46° x 36° 36° x 27° 20° x 15° 14° x 11°
160x120 52° x 40° - 18° x 14° - -
640x480 - - - 26° x 20° 18° x 14°
IFoV2 (milliradians)  
320, 160 6.032 2.667 2.000 1.086 0.760
640 - - - 0.714 0.500
Minimum Focus Distance ~5 inches ~5 inches ~12 inches ~27 inches ~72 inches
Hyperfocal Distance3 0.25m 5 meters 7.5 meters 26 meters 35 meters
Hyperfocal Depth of Field4 - 2.5 meters 3.8 meters 13 meters 18 meters
Weight (Lens & Lens Mount only) 55g 56g 33g 88.5g 128g
Length (Lens only) 0.377" 1.209" 0.769" 1.709" 2.632"
Diameter (maximum) 1.250" 1.654" 1.024" 1.654" 1.772"
Coating Type High Efficiency High Durability Hard Carbon5
Nominal Wavelength 8.0 to 14.0 microns

1 Field of View describes the angular measure of a scene imaged with the given pixel array, expressed as degrees in horizontal by vertical directions.
2 Instantaneous Field of View is the angular measure of a single pixel. Small angles are usually measured in milliradians. The IFoV is the pixel size (in microns) divided by the lens focal length
3 Hyperfocal distance is the distance beyond which all objects are acceptably sharp, for a lens focused at infinity.
4 Hyperfocal depth of field is the zone of acceptable sharpness. Increasing the depth of field increases the sharpness of an image. Smaller apertures (higher f/numbers) increase the depth of field.
5 Coating Type for 35mm and 50mm configurations of Photon 640 will be High Durability, not Hard Carbon.


4. I need to use the Photon to image an object at close range. Is it possible to adjust the focus of Photon lenses manually? What is the range of focus? What is the close focus distance?

We describe the range of focus to mean the hyperfocal range, that is, the range between infinity and some point less than infinity through which the lens remains in focus. All Photons with lenses are factory-calibrated with the lens locked at infinity focus.

All of the currently available Photon 320 lenses (14.25mm, 19mm, 35mm, 50mm) use a screw-thread mount. The lens focus is locked by a small setscrew. All of the currently available Photon 640 lenses (35mm, 50mm) also use a screw-thread mount, however the Photon 640 lens adapters use a collar with a socket-head cap screw instead of a setscrew.

To adjust the lens focus to something other than infinity focus, or to achieve the shortest possible focus, requires that the setscrew or socket-head cap screw be loosened. It may not be possible to lock the focus at a close focus point since in some cases the lens in almost out of its holder. FLIR does not offer spacers for macro focus. Extreme care should be used to avoid cross-threading the lens in the lens adapter.

The table below shows the approximate minimum focus distance for each Photon 320 lens type. Although Photon lenses are capable of focusing to shorter object distances, it is important to note that they are not designed, calibrated, or specified for this purpose. All Photon camera/lens calibrations are performed at infinity focus. Image space f/numbers can change under extreme finite conjugates. Very close focus applications using a Photon calibrated at infinity focus may result in possible image anomalies, non-uniformities, and/or degraded performance. Customers should be aware of these limitations and evaluate the images for issues.

Lens Focal Length 14.25mm Lens 19mm Lens 35mm Lens 50mm Lens
Close Focus Distance ~5 inches ~12 inches ~27 inches ~72 inches


5. How much does the Photon camera weigh?

Photon Weight Information

The camera weight will depend on which type of cover is installed, if any, and whether or not a wearsaver adapter is used. The table below shows the approximate weight of the different camera/lens configurations, as well as the weights for the covers and wearsaver connector. There can be some variation in the actual weight, but the figures shown for the Core + Lens should be accurate to within +/- 2 grams.

Weight Table For Photon 320 and 160
  No Lens 6.3mm1 14.25mm2 19mm 35mm2 50mm2
Core 97g 132g 153g 130g 185.5g 225g
Wearsaver Cover 16g 16g 16g 16g 16g 16g
Wearsaver 7g 7g 7g 7g 7g 7g
Core + Wearsaver + Cover 120g 155g 182g 158g 212g 253g
1 Only available for Photon 160
2 Only available for Photon 320

Weight Table For Photon 640
  No Lens 35mm 50mm
Core 113g 227g 280g
EMI Board cover 22g 22g 22g
EMI Board 24g 24g 24g
Core + EMI Board + Cover 159g 273g 326g


6. Is it possible to get the Photon camera with an athermal lens?

All of the currently advertised Photon lenses are of a passive athermal design. This means that the lenses mechanically self-adjust to changes in temperature such that the lens remains in focus over wide ambient temperature ranges.


7. If a lens-less camera core is purchased, how can it be calibrated with a lens?

FLIR offers, for sale, a WindowsTM application program called Alt Lens Cal that allows users to perform a supplementary calibration of the camera with a lens. The part number is 110-0102-46. Typically this software is used by customers that furnish their own optics.

This calibration requires the use of at least one blackbody source. The calibration routine calculates gain terms on a per-pixel basis with the customer-supplied lens attached to the Photon core, and stores the customer-performed calibration in non-volatile camera memory.

Alt Lens Cal software requires a customer-furnished PC, which should be dedicated to this task. The original factory calibration coefficients are first downloaded from the camera into a file on the PC. Then, via the supplementary calibration process, the user uploads new calibration data directly into the camera. This can be done multiple times if needed, and the user can actually build a library of calibration files for a camera.


7. Is the spectral response of the microbolometer array 7.5µ to 13.5µ, or is the spectral response a function of the lens?

The spectral response of the microbolometer is influenced by all of the optical interfaces between the focal plane array and the object being imaged. These include the sensor vacuum package front window, the lens, any protective windows in front of the lens, and finally atmospheric transmission between the object and the camera. Standard configuration vacuum packages (as of Jan 2007) have front windows that define the short wavelength cut-on of 7.5 um, while the bolometer itself defines the long wavelength cut-off of 13.5 um, assuming negligible atmospheric attenuation.


7. Can the Photon rear cover be removed? What other rear cover options does FLIR offer for Photon?

Unless otherwise specified by an OEM agreement, all Photons with lenses are delivered with a rear cover. This cover affords some protection to the electronics, but it can be removed by the customer. There is no credit given for unused rear covers. The standard rear cover has a cut-out to allow access to the SAMTEC 30-pin connector. This cut-out is sized to enable the wearsaver adapter to be installed.

Some customers have expressed concern about the integrity of the cable-to-camera connections in environments where vibration or low g-forces may exist. An optional rear cover is available for Photon that encloses the wearsaver adapter, and jack posts are provided to which the interface cable can be securely attached. The wearsaver cover is furnished as part of the Photon Accessory Kit, or may be ordered separately using part number 261-1273-00. The wearsaver cover is provided as a separate item in addition to the standard cover when delivered.

NOTE: For the Photon 320 camera, the wearsaver adapter is required for compatibility with the Ethernet Module. FLIR also recommends the wearsaver cover in cases where the Ethernet Module is used with a Photon 320.

For the Photon 640 camera, the EMI cover accessory is required for compatibility with the Ethernet Module.

Photon 320
261-1273-00 Wearsaver Cover. Provided as part of the optional Photon Accessory Kit (along with the Wearsaver Connector). Used by most one-off customers and some OEM customers due to its secure connection ability.
261-1082-00 OEM Shipping Cover. Provided as a standard part of the Photon Camera Core configuration.
500-0312-00 EMI Rear Cover. Optional cover that provides some EMI mitigation by means of a separate electronics board, shielding, and grounding.


8. Can two cameras be set up as master and slave for synchronization purposes?

Photon was designed to accept a 3-Volt signal and send a 3-Volt signal, so one Photon can drive one or more Photons in slave mode. There are serial commands to designate a Photon as the master or slave camera.

Photon provides the capability to synchronize the frame start sequence using an external input. The camera completes the frame sequence using internal timing and then waits for the synchronization pulse before starting the next frame. If the sync pulse rate exceeds the maximum FPA frame rate (nominally 30Hz), sync pulses will be ignored and there will be frames dropped from the stream. (Note: this will result in lost data). While operating in slave mode, the analog video output signal is dependent upon the input frame sync rate for compliance with video standards.

Slave mode in slow video mode cameras continues to require an external sync pulse at the nominal 30Hz/ 25Hz frame rate. Digital output frame rate and analog video update rate are both at one fourth the input external frame sync rate independent of video modes (NTSC/PAL).


9. Is a protective enclosure available for Photon?

FLIR's PathFindIR product is one option. PathFindIR comprises a Photon/19mm lens in a magnesium housing that is completely sealed. The field of view is 36 degrees horizontal. A hermetic connector provides the electrical interface for input power and output video. For more information, refer to http://www.corebyindigo.com/products/core_pathFindIR.cfm. There are no PathFindIR lens options offered other than the 19mm (36-degree FOV).

There are also several FLIR Security & Surveillance products available that incorporate Photon cores into environmentally sealed systems, including the ThermoVision Integration Series (TVIS), Wide Eye, Security HD, and Sentinel. Please refer to http://www.flir.com/imaging/Security/Products/index.aspx for more information about these products.


8. How are FLIR's microbolometer arrays packaged? Are they under vacuum? Why?

The microbolometer sensing elements are thermistors that are suspended, as bridge structures, above a readout integrated circuit (ROIC). The sensing elements need to be able to change temperature individually in response to small amounts of heat energy. In order to allow this response to small changes in radiant energy, the sensing elements must be thermally isolated from the ROIC. To achieve the thermal isolation, we put the sensor in a high-quality vacuum to eliminate the air gap that would otherwise exist between the thermistors and the ROIC. An air gap would enable a conduction path that effectively dampens the sensor responsivity.