Large pixel CCD cameras are better than megapixel CMOS cameras for neutron imaging.

Camera makers often emphasises the advantages of megapixel CMOS cameras, which are by far the most popular and usually the most suitable for commercial applications of optical imaging; they are also less expensive to make. Why then don't we use megapixel CMOS cameras for radiography ? Both CCD and CMOS cameras are optimised for imaging directly with light. The largest markets are for consumer cameras, industrial and security applications, and biological science, all of which have different requirements to neutron imaging. Expensive cameras are produced for biological science, but such cameras have few advantages for neutron imaging. We use cameras designed for amature astronomy, where the technical requirements are closest to those needed for neutron imaging (longer, low noise exposures with high dynamic range).
See Why buy a camera instead of making one.

CCD/sCMOS detectors. We can use the most expensive cameras, but price increases rapidly for minimal practical advantage.

Detector Slim CCD #FS14 #FS60 LF40+ PCO.2000 #VS60 PCO.edge gold 4.2 11002
Type Interline CCD
Interline CCD
Interline CCD
Interline CCD
Interline CCD
Interline CCD
Scientific sCMOS
Interline CCD
Resolution pixel 752 x 580 1392 x 1040 2759 x 2200 2048 x 2048 2048 x 2048 2759 x 2200 2048 x 2048 4008 x 2672
Image diag. mm 8 (1/2") 11 (2/3") 16 (1") 21.4 (4/3") 21.4 (4/3") 16 (1") 18.8 (4/3") 43.3 (35mm)
Image area mm 6.40x4.75 8.98x6.71 12.49x9.99 15.15x15.15 15.15x15.15 12.49x9.99 13.3 x 13.3 37.25 x 25.70
Pixel size µm* 8.6 x 8.3 6.45 x 6.45 4.54 x 4.54 7.4 x7.4 7.4 x7.4 4.54 x 4.54 6.5 x 6.5 9.0 x 9.0
Quantum effic* ~75% ~75% ~75% 55% 55% ~75% >70% 50%
Fullwell e- ** ~40,000 ~20,000 ~20,000 ~40,000 ~40,000 ~20,000 ~30,000 ~60,000
Read noise e- ** 10 4 5 11 6 6 1 13
Dark c. e-/pix/s <0.1@amb. 0.004@-10 °C 0.003@-10 °C 0.01@-20 °C 0.01@-20 °C 0.002@-10 °C <0.02@-30 °C <0.03@-20 °C
Peltier Cooling uncooled Δ -27 °C Δ -27 °C Δ -40 °C Δ -50 °C Δ -35 °C Δ -30 °C Δ -38 °C
Read time (s)*** 0.2 1 to 3 1 to 3 3 to 6 0.5 to 0.2 0.1 to 1 0.01 to 0.02 12 to 22
A/D Readout** 16-bits 16-bits 16-bits 16-bits 14-bits 16-bits 16-bits 16-bits
Binning h,v x1 x2 x4 x8 x1 x2 x4 x8 x1 x2 x4 x8 x1 x2 x4 x8 x1 x2 x4 x8 x1 x2 x4 x8 x1 x2 x4 x1 x2 x4 x8
Mount CS-mount C-mount C-mount F-mount F-mount C- or F-mount C- or F-mount F-mount
Trigger signals Software Software Software Software Hardware Hardware Hardware Software
Interface*** USB 2.0 USB 2.0 USB 2.0 USB 2.0 USB 3.0 USB 2.0 USB 3.0 USB 2.0
Relative cost <1 2 4 5 20 4.5 16 8

#   The VS14 and VS60 are faster readout cameras with the same 2/3" or 1" Sony EXview HAD II (ICX) CCDs as the less expensive FS14 and FS60.
     Our larger "Kodak" (KAI) CCDs are read out more slowly to reduce noise. They are also used in much more expensive cameras with faster readout.
     The collimation and quality of your neutron beam-line will usually be the limiting factor for neutron imaging, not the camera.

*   Light capture per pixel is proportional to the pixel area and its quantum efficiency (at 525nm)
     Fullwell Capacity is the number of electrons that can be stored without overflow (blooming)
     Fullwell Capacity is also proportional to pixel area, but also depends on anti-blooming design
     Noise can be "Dark current" due to thermal energy, or "Read noise" due to electronic readout
     Dark Current can be reduced by cooling for long exposures. Modern Sony ICX CCDs have exceptionally low dark current.
**  Dynamic range is the ratio of Fullwell capacity to Noise, & is lower than the 16-bit (65,536) readout
     Dynamic Range in Decibels DR= 20log (Fullwell capacity/Noise)dB eg typically DR= 5,000= 74dB
     Dynamic Range is often exagerated by neglecting dark noise (true only for very short exposures)
     Note that electron- or photon-multiplied cameras generally have a low dynamic range eg DR= 1,500= 64dB
     A high dynamic range means that contrast between slightly different intensities is better, important for imaging
*** USB 2.0 is limited in practice to ~280Mbits/s i.e for a 2048x2048x16 bit camera to ~4 frames/sec (fps)
     USB 3.0 is limited in practice to ~4000Mbits/s i.e for a 2048x2048x16 bit camera to ~64 frames/sec (fps)

In our "interline" CCDs, charge accumulated by photo-sensitive columns is quickly transferred to adjacent storage columns. The advantage is that smearing is avoided during readout, so a mechanical shutter is not needed. Some of the chip area is used for storage, but that is compensated by the use of micro-lenses over every pixel. Sony sensors are typically ~75% sensitive to the mainly green (540nm) light emitted by neutron scintillators, and at that wavelength there is little advantage for more expensive "back-illuminated" CCDs. These explanations are simplified, but summarise why we use "slow" readout CCDs for neutron imaging.

Of the high-end cameras, the PCO.2000 uses the same Kodak KAI-4022 interline CCD as our LF40+ and has similar imaging performance, except that it uses more expensive electronics with faster readout. Our VS60 is a less-expensive fast readout CCD alternative to the CIS2020 sCMOS camera, whose main advantage is the even faster readout for lower readout noise (but higher dark current, which limits exposure times). The sCMOS camera is then best suited for fast imaging on high flux sources, while our cooled CCD cameras are best suited for lower flux imaging with longer acquisitions (>1s).

Our small cameras use Sony EXview HAD CCDs, which are very efficient, with low noise and fast readout; the chips are also small, limiting light capture but permitting the use of inexpensive fast C-mount lenses. Our f/1.0 lens is twice as fast as an f/1.4 lens. More important than the efficiency of the CCD itself, the efficiency of the camera is proportional to the ratio of the CCD to scintillator area, so our smaller CCDs are matched to our smaller cameras.