KL400 BI Images

Gerald Rhemann

Tivoli Astrofarm, Namibia

Eta Carina Nebula, NGC3372

Eta Carina Nebula, NGC3372

NGC6726 and NGC6727

M8

NGC3324 and NGC3293

"But one thing became clear to us during the test [of the KL400] at this stay -the course is set for the future. In less than an hour one can record depths which can only be achieved with a CCD over many hours." --Gerald Rhemann

Kepler Cooled sCMOS Cameras

The Kepler Series is a giant step forward in throughput, providing faster digitization and high speed interfaces. Sensors currently supported include front and back illuminated sCMOS.

1. USB3.0 (3 Gbps)
2. Optional QSFP high speed fiber interface
3. Optional Electromechanical Shutter for Remote Acquisition of Calibration Frames
4. Choice of Windows - View Transmissivity Curves
5. Air Cooling or Liquid Cooling (LC connectors sold separately)
6. Deep Cooling (up to 45C below ambient)
7. Optional Anti-Dew Technology (ADT)
8. LDR and HDR modes
9. Small Footprint (as small as 10.2 x 10.2 x 10.7 cm)
10. Reaches operating temperatures in 10 minutes
11. View Kepler Overview pdf

For details regarding Kepler Operational Modes and a Signal to Noise Comparison of CCDs versus CMOS, please see the bottom of this page.

Need Extremely Accurate Time Logging? See the Kepler Image Time Stamp.

Maximize Your Field of View with our New Large Format Kepler KL6060 sCMOS Camera

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. (Click here for the brochure)

Front Illuminated Sensors

Kepler KL400FI: 2048 x 2048, 11 micron

Kepler KL4040FI: 4096 x 4096, 9 micron

Kepler KL6060FI: 6144 x 6144, 10 micron

Back Illuminated Sensors

Kepler KL400BI: 2048 x 2048, 11 micron

Kepler KL4040BI: 4096 x 4096, 9 micron

Kepler KL6060BI: 6144 x 6144, 10 micron

Kepler DC23084 CCD Camera: 4096 x 4096, 15 micron

Kepler Drawings

KL400, No Shutter, T-mount

KL400, No Shutter, FLI dovetail

KL400, 45mm Shutter, FLI Dovetail with 2" Aperture

KL400, 45mm Shutter, CenterLine ZTA Flange

KL400, 45mm Shutter, Atlas ZTA Flange

KL400, 45mm shutter, FLI Dovetail with 2.55" Aperture

KL400, 45mm shutter, CFW9 Flange

KL4040, 65mm Shutter, FLI Dovetail

KL4040, 65mm Shutter, CenterLine ZTA Flange

KL4040, 65mm Shutter, Atlas ZTA Flange

KL4040, 65mm Shutter, CFW9 Flange

KL4040, No Shutter, Flat Front

KL4040, No Shutter, FLI Dovetail

KL6060, 90mm Shutter

KL6060, Round, 90mm Shutter

KL6060, No Shutter

KL6060, No Shutter, CFW9 Flange

DC23084, 90mm Shutter

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.

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 has 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.