Specifications: KL4040 vs. PL16803
| KL4040 | PL16803 | |
| Sensor Type | Front Illuminated CMOS | Front Illuminated CCD |
| Active Pixels | 4096 x 4096 | |
| Pixel Size | 9 x 9 microns | |
| Effective Area | 36.9 x 36.9 mm | |
| Sensor Diagonal | 52.1 mm | |
| Full Well Capacity | 70000 electrons | 100000 electrons |
| Frame Rate (rolling) | 23 fps (QSFP V2) | 11 seconds per frame |
| Read Noise (Rolling) | 3.7 e- HDR (800 MHz) | 10 e- (1 MHz) |
| Dynamic Range | 86 dB HDR | 80 dB (1 MHz) |
| Peak QE | 74% | 60% |
| Cooling | Air (Optional Liquid) | |
| Dark Current | 0.08 eps at -10C | 0.005 eps at -33C |
| Interface | USB 3.0 (Optional QSFP) | USB 2.0 |
| Data Bit Depth | 16 bit | |
| Optional Mount | F-mount | |
| Subarray Readout | Yes | |
| Electromechanical Shutter | Optional 65mm | Standard 65mm |
| External Trigger In/Out | Yes | |
| Software | FLI Pilot | FLIGrab |
| SDK | Kepler (Open Source) | USB 2 (Open Source) |
The Kepler KL4040 continues FLI's tradition of excellence. Like the ProLine PL16803, the KL4040 uses a 4k x 4k sensor with 9 micron pixels. The difference is the ProLine used a traditional CCD while the Kepler uses a scientific CMOS sensor. CMOS sensors behave very differently from CCDs: they are more flexible, but they are also much more complex.
The table below is a comparison of the ProLine PL16803 and the Kepler KL4040 cameras, using a low flux value of 1 photon/pixel/second and dark current values given in the chart to the right.
| Exposure (sec) | 4040 SNR | 16803 SNR |
| 1 x 900 | 22.5 | 19.3 |
| 5 x180 | 21.8 | 14.7 |
| 10 x 90 | 20.9 | 11.9 |
Summary: A Paradigm Shift
It is no surprise that the CCD’s best performance is with a single long exposure. What may be surprising is the Kepler KL4040 appears to have a better signal-to-noise ratio than the PL16803 even with a single long exposure. The signal-to-noise ratio of the KL4040 is better than the PL16803 even when using short exposures that are stacked!
The benefit of taking multiple short exposures is the option to discard a bad exposure ruined by satellite trails, tracking errors, or bad seeing (etc.). Incredible low-noise images are now possible with a single long exposure or many stacked short exposures. The KL4040’s superior performance allows it to be used for a wide range of applications and requirements.
Quantum Efficiency: KAF-16803 versus GSense4040 CMT
