You only need to read these instructions if you have our FLIR (Point Grey) CMOS camera.
If you have the high resolution CCD option, you need these instructions instead.
If you have the Macro camera, you need these instructions instead.
If you have the 1CCD Laue camera, you need these instructions instead.
If you have the 2CCD Laue camera, you need these instructions instead.
If you have a standard video camera, you need these instructions instead.
These instructions are for Windows-10; for other versions they may be slightly different.

The FLIR (Point Grey) IMX249 CMOS Camera

NeutronOptics x-ray or neutron cameras can be supplied with an optional FLIR (Point Grey) IMX249 CMOS Camera when high frame rates are required (up to 41 fps). The maximum exposure of the IMX249 camera with USB3 is only 4 seconds (30 seconds for the GigE version); dark current noise is higher for CMOS cameras, limiting them to short exposures.

The IMX249 is a slower frame-rate version of the IMX174, and currently the best Sony CMOS detector for low-light imaging. It is a relatively large sensor, with big pixels favouring light capture, with high Quantum Efficiency (QE) The USB3 camera is powered by a 5m USB cable, and the GigE version by a powered GigE cable. Note the cooling fins added to the FLIR camera to limit temperature (and dark current), and the carbon fibre x-ray window.

  • Sensor Type: Sony Pregius CMOS IMX249
  • Image size: Diagonal 13 mm (Type 1/1.2")
  • Resolution: 1920 x 1200
  • Pixel Size: 5.86 x 5.86 µm
  • Binning: on-chip binning not available with CMOS
  • High sensitivity: (QE~80% at 500-600nm)
  • High dark current: (~10 e/s ambient)
  • Full well capacity: >30,000 electrons (dynamic range)
  • ADC: 16 bit grey scale, optional filtering and distortion
  • Readout Noise: ~7 e- (low readout noise)
  • Readout Time: ~0.025s (up to 41 fps frame rates)*
  • Interface: USB 3.1 High Speed with 5m USB cable
                     or PoE GigE ethernet for long distances
  • Power: power over USB (or Ethernet)
  • Maximum Exposure Length: 4s USB3, 30s GigE
  • SDK: FLIR (Pt Grey) FlyCapture and Spinnaker C++ SDK
* Very high frame rates (41 fps) are only possible with short USB3 cables (5.0m).
But rates of 9 fps can be obtained even with 10+ metre amplified USB2 extension cables.

Install the FLIR (Point Grey) Camera Driver

  • Download the 32-bit version of FlyCapture from the FLIR web site (registration)
    The more compatible 32-bit version is recommended even if you have a 64-bit PC
  • Install FlyCapture, which also installs the 32-bit camera drivers
  • You can use FlyCapture to control the camera, but we recommend instead SharpCap
  • Download the 32-bit version of SharpCap. These instructions refer to the 3.2 version.

FLIR (Point Grey) FlyCap2 for Camera Control

FlyCap2 was designed for high frame rate and video capture in daylight, and contains additional features you probably won't need for slower x-ray or neutron imaging. The camera will be automatically recognised if it is plugged in; you just need to click on it. (FlyCap2 is designed to control multiple cameras simultaneously). A window will open displaying the image using default exposure time, gain etc. shown to the left of the image. (Click the image to enlarge it).

To change these, click the “Settings” menu and “Toggle Camera Control Dialogue” to open the control window. Note the high sensor temperature, which contributes to dark current noise since the camera is not cooled. Uncheck Shutter, Gain and FrameRate. Also switch the FrameRate “Off”. You can now increase the Shutter (Exposure) to a maximum of 4 seconds (USB model). The FrameRate will then be 0.25 fps as shown in the image window. Increasing the Intensity, Exposure, Sharpness and Gamma only changes the display, not the saved image. You can increase the gain from “0.0” but this will also increase noise in the image, as shown in the right image below. In the Settings window, click on “Custom Video Modes” and select Mono16 rather than Mono8, and save the images as 16-bit TIF files to retain maximum dynamic range. (Click the images to enlarge them).

Of the remaining control dialogues, only “Camera Information” is of much use, but there is a control for hardware synchronisation via GPIO. Instead of FlyCap, we recommend you use SharpCap, which also contains unneeded controls, but which has a more intuitive interface for low-light imaging.

SharpCap 3.2 Camera Control and Acquisition

SharpCap 3.2 was designed for amateur astronomers, and contains additional features that you will not need for x-ray or neutron imaging. SharpCap can be used with a wide variety of cameras, including our "slim" lodestar camera as well as our high resolution Atik cameras (via ASCOM). The camera will be automatically recognised if it is plugged in, and you just need to choose it from the “Cameras” menu. A window will open with the image and camera controls on the right. You can arrange the order of controls by dragging the 3-line icon. An exhaustive SharpCap User Manual is available, but the instructions below may be sufficient to start with. (Click the image to enlarge it).

In the "Camera Controls" you can set the Exposure (toggle LX mode for exposures >1 second), the Gain (higher gains also increase noise) and you can read the sensor temperature. In the "Capture Format", select TIFF or FITS and Mono16. You can drag the vertical line in the "Display Histogram" to stretch the intensity display to emphasise the lower intensities (and see the noise). Tip: set a "Default Profile" and the connected camera will be automatically selected with those settings when SharpCap starts.

Stacking short exposures in SharpCap 3.2

An important advantage of SharpCap is real-time stacking of a series of short exposures. This allows you to judge when you have sufficient intensity (and to overcome the maximum exposure limit of the FLIR camera). Click on the "Live Stack" icon above the image display to open this stacking window. You can drag this window so that it does not cover the image. Switch off "Align Frames" which refers to alignment based on stars. Most of the controls to the right are also for astronomers; only the live histogram is useful, but normally you might save the summed stack as a 32-bit image and filter noise from it with imageJ.

You can also use imageJ to stack a series of short exposures, which allows filtering of noise from the individual images before averaging. For very short exposures this may be better than averaging first and then filtering. Use the SharpCap menu Capture/Start_Capture then enter the number of images to be saved. After capturing those images, use the ImageJ menu File/Import/Image_Sequence, open the first image, and then OK to import all images in that directory into a displayed stack. Use Image/Adjust/Brightness-Contrast to examine the noise, and apply Process/Noise/De-speckle to all images. You may need to De-speckle twice. Finally sum or average the stack using Image/Stacks/Z-Projection.

For long stacked exposures you may see a diffuse background patch due to amplifier glow.
Depending on the speed of your computer, frames may be dropped for frame rates >8 fps.

Hints on getting Optimal Images

  • The exposure time depends of course on the intensity of your beam
  • Exposure time and frame rate can be controlled separately for short exposures
  • Use "Process/Noise/De-speckle" in ImageJ to remove noisy pixels from saved files
A PDF version of these instructions is available,