FLI Kepler
The Kepler Series is a giant step forward in throughput, providing faster digitization, higher speed interfaces, and up to 35 channel readout. Sensors currently supported include front and back illuminated sCMOS. Future developments will include interline transfer CCDs and EMCCDs.
- USB3.0 (3 Gbps)
- Optional QSFP high speed fiber interface
- Optional Electromechanical Shutter for Remote Acquisition of Calibration Frames
- Choice of Windows – View Transmissivity Curves
- Air Cooling or Liquid Cooling (LC connectors sold separately)
- Deep Cooling (up to 45°C below ambient)
- Optional Anti-Dew Technology (ADT)
- LDR and HDR modes
- Small Footprint (as small as 10.2 x 10.2 x 10.7 cm)
- Reaches operating temperatures in 10 minutes
- View Kepler Overview pdf
Available with a front-illuminated sensor or high-QE back-illuminated sensor, the Kepler KL6060 camera is capable of taking up to 19 frames per second using the optional QSFP fiber interface. This affordable camera is a game-changing solution for Space Debris Detection and Space Situational Awareness applications and is ideal for universities or dedicated amateurs who want to capture every possible photon.
Kepler KL400 Operational Modes
The KL400’s Low Dynamic Range (LDR) mode reads the image once and digitizes it to 12-bits. The user has eight gains to select from in LDR mode. Adjusting the gain affects full well size, dark current growth, and linearity.
The High Dynamic Range (HDR) mode reads the pixels twice, digitizing with different gains. (Unlike CCDs that only read the charge from each pixel once, CMOS sensors can measure the charge multiple times.) The two images are merged to create a 16 bit image with the linearity of a single image, thus allowing an HDR image to show detail in both low-count and high-count areas of an image. Because of the additional read time, the maximum HDR frame rate is half that of the LDR mode.
The Kepler camera also features a Low Dark Current (LDC) options for both LDR and HDR. When used, the LDC option minimizes dark current at the expense of reduced full well capacity. For short exposures where dark current growth is not a problem, LDC is not generally used. Standard modes (not LDC) provide the highest full well capacity and widest dynamic range. On the other hand LDC mode is very useful for imaging dim objects that require very long exposures where dark current growth can be significant.
The following may be useful in making the decision on which mode is most appropriate:
Choose LDR mode for required frame rate greater than 24 FPS (exposures <42 ms).
Choose HDR mode for a dynamic range greater than 0 – 4095 counts
Choose LDC when your exposures are sufficiently long that dark current growth uses a significant percentage of full well capacity. (Also cool sensor to lowest possible operating temp.)
Do not choose LDC for short exposures.
A Signal to Noise Ratio Comparison: PL16803 CCD vs. KL4040 sCMOS
The ProLine PL16803 has been the de facto standard for astrophotography since its release in 2006, and the Kepler KL4040 continues the tradition of excellence. Both cameras use a 4k x 4k sensor with 9 micron pixels. The difference is the ProLine uses a traditional CCD while the Kepler uses a Scientific CMOS sensor.
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.
| Sensor | KAF-16803 CCD | GS4040 sCMOS |
|---|---|---|
| Average QE 400-700 nm | 50.7% | 69.8% |
| Dark Current | 0.001 eps | 0.15 eps |
| Read Noise | 10 e- | 3.7 e- |
| Throughput | 1 MHz | 800 MHz |
| Full Well Capacity | 100000 e- | 70000 e- |
| Dynamic Range | 10000 : 1 | 18900 : 1 |
| SNR 900 sec | 19.2 | 22.5 |
| SNR 5 x 180 sec | 14.7 | 21.8 |
| SNR 10 x 90 sec | 11.9 | 20.9 |
