Moravian instruments, Inc., source: http://www.gxccd.com/art?id=441&lang=409, printed: 24.5.2017 6:15:06

Main page  Products  CCD cameras

G2-0402, G2-1600, G2-3200, G2-8300, G2-2000 and G2-4000 CCD Cameras
 G2 series of small format CCD cameras uses high sensitive, low noise OnSemi Full-Frame and Interline-Transfer CCD detectors. While high-speed USB2.0 interface allows plug-and-play operation and ensures download time within a few seconds, optional Ethernet interface provides camera connection to practically unlimited distance. Advanced analog electronics ensures uniform frames without artifacts and very low read noise. Efficient, regulated two-stage Peltier cooling keeps detectors frozen to minimize dark current. Compact and robust camera head integrates all electronics, mechanical shutter and optional internal filter wheel. Various threaded and bayonet adapters enable attaching of the camera to almost any optical system and numerous accessories like autoguiding cameras, off-axis guider adapters, external filter wheel etc. allow tailoring of the imaging system to almost every application.

All members of the G2 series of cooled CCD cameras are designed for low-light imaging applications, requiring very high sensitivity and very low noise and dark current. However, the G2 series comprises numerous model, each suitable for a particular application area in astronomical research, astro-photography, microscopy, life-sciences, material research etc.

G2-0402, G2-1600 and G2-3200 models are equipped with Full-Frame, NABG detectors. Their features make them especially suitable for research applications:

  • Very high sensitivity with peak QE above 80%.

  • High full-well capacity (up to 100ke- in the case of G2-0402 and G2-1600 models).

  • Non-ABG detectors with linear response to light.

G2-8300 still employs Full-Frame architecture CCD, but thanks to ABG this particular model is especially popular among astro-photographers:

  • KAF8300 CCD detector is equipped with anti-blooming gate (ABG), which protects electron leaks from saturated pixels to neighboring pixels when a bright star appears in the field of view.

  • Detector corresponds to the so-called “4/3 standard” and its imaging area 18.1נ13.7mm is the largest of all detectors used in the G2 series.

  • High resolution (more than 8MPx) and relatively small pixels (5,4נ5,4μm) makes this camera ideal for use with short focal length telescopes (or with ordinary photographic lenses).

G2-2000 and G2-4000 models use Interline-Transfer CCD detectors, bringing some unique features:

  • Electronic shuttering allows very short exposures of bright objects.

  • Fast windowing allows reading of arbitrary detector sub-frame faster than in the case of KAF CCD detectors.

  • Anti-blooming gate ensures proper images of bright stars in the field of view without blooming spikes, but it still does not harm linearity, so these cameras can also be used for research applications.

All members of the G2 series share the same design, making them powerful research and imaging tools:

  • Lowest possible read noise, limited by CCD detector itself.

  • Uniform frames without artifacts.

  • High dynamic range, 16-bits digitization.

  • Efficient and precisely regulated cooling with optional heat exchanger for liquid coolant.

  • Compact camera head, small and lightweight enough to be attached even to small telescopes.

  • Integrated all-in-one design with USB and power connectors directly on the camera head.

  • Integrated mechanical shutter not to bother with covering the telescope when taking dark frames.

  • Optional integrated filter wheel.

  • Single-voltage power supply enabling operation from 12Vbattery or “brick” adapter.

  • Plug and play installation.

  • Robust construction to sustain every-day usage.

  • Rich software support.

No matter if your target is reliable scientific data or beautiful images of deep-sky objects, G2 CCD cameras are able to provide both.

G2 Camera Overview

G2 camera head is designed to be easily used with a set of accessories to fulfill various observing needs. Camera head itself is manufactured in two different variants:

  • Camera with internal filter wheel.

  • Camera with control port for external filter wheel. This model allows attachment of several variants of external filter wheels with various number of filter positions and sizes.

Camera head and numerous accessories comprise imaging system, capable to be tailored for many applications.

  1. G2 camera head with internal filter wheel.

  2. G2 camera head without internal filter wheel, ready for attaching of external filter wheel.

  3. G0 Guider camera.

  4. G1 Guider camera.

  5. External filter wheel.

  6. Off-axis guider adapter, optionally with M42נ0.75 thread (T-thread) or M48נ0.75 thread.

  7. Thin spacer. Camera with internal filter wheel and this spacer has the same back focal distance as camera with external filter wheel.

  8. Thick spacer. Camera without internal filter wheel and this spacer has the same back focal distance as camera with external filter wheel.

  9. Nikon bayonet adapter for Nikon compatible lenses.

  10. Canon EOS bayonet adapter for Canon compatible lenses.

  11. T-thread (M42נ0.75) adapter.

  12. 2-inch barrel adapter.

  13. Gx Camera Ethernet Adapter allows connection of up to 4 Gx cameras of any type on the one side and 1Gbps Ethernet on the other side. This adapter allows access to connected Gx cameras using routable TCP/IP protocol over practically unlimited distance.

  14. The whole system is controlled from a host PC.

G2 cameras are designed to work in cooperation with a host Personal Computer (PC). As opposite to digital still cameras, which are operated independently on the computer, the scientific slow-scan, cooled cameras usually require computer for operation control, image download, processing and storage etc. To operate G2 camera, you need a computer which:

  • Is compatible with a PC standard.

  • Runs a modern 32-bit or 64-bit Windows operating system.

    Remark:

    Drivers for 32-bit and 64-bit Linux systems are also provided, but camera control and image processing software, supplied with the camera, requires Windows operating system.

  • Provides at last one free USB port.

    Remark:

    The current series of G2 cameras are designed to operate with USB2.0 high-speed (480Mbps) hosts. Although they are fully backward compatible with USB1.1 full-speed (12Mbps) hosts, image download time can be somewhat longer if USB1.1 connection is used.

  • Alternatively it is possible to use the Gx Camera Ethernet Adapter. This device can connect up to four Gx cameras of any type (not only G2, but also large-format G3 and G4 as well as G0 and G1 guiders) and offers 1Gbps and 10/100Mbps Ethernet interface for direct connection to the host PC. Because the PC then uses TCP/IP protocol to communicate with the cameras, it is possible to insert e.g. WiFi bridge or other networking device to the communication path.

G2 camera, External Filter Wheel, Off-Axis Guider adapter and G1 guider camera on the telescope

G2 camera, External Filter Wheel, Off-Axis Guider adapter and G1 guider camera on the telescope

G2 Camera Models

Available models of G2 CCD cameras:

Model CCD Chip ABG Color mask Resolution Pixel size Imaging area Download time
G2-0402 KAF-0402ME No None 768נ512 9נ9μm 6.9נ4.6mm ~ 0.5s
G2-1600 KAF-1603ME No None 1536נ1024 9נ9μm 13.8נ9.2mm ~ 1.8s
G2-3200 KAF-3200ME No None 2184נ1472 6.8נ6.8μm 14.9נ10mm ~ 3.8s
G2-8300 KAF8300 Monochrome >1000 None 3358נ2536 5.4נ5.4 μm 18.1נ13.7mm ~ 9.8s
G2-8300C KAF8300 Color >1000 Bayer RGBG 3358נ2536 5.4נ5.4 μm 18.1נ13.7mm ~ 9.8s
G2-2000 KAI-2020 Monochrome >300 None 1604נ1204 7.4נ7.4μm 11.9נ8.9mm ~ 2.1s
G2-2000C KAI-2020 Color >300 Bayer RGBG 1602נ1202 7.4נ7.4μm 11.9נ8.9mm ~ 2.1s
G2-4000 KAI-4022 Monochrome >300 None 2056נ2062 7.4נ7.4μm 15.2נ15.3mm ~ 4.5s
G2-4000C KAI-4022 Color >300 Bayer RGBG 2054נ2060 7.4נ7.4μm 15.2נ15.3mm ~ 4.5s

G2 Camera Technical Specifications

CCD Chip

G2 cameras use OnSemi KAF Full-Frame and KAI Interline-Transfer CCD detectors. Advanced manufacturing techniques like transparent electrodes and microlensing ensure more than 80% peak quantum efficiency on some models. The inherent dark current of these detectors is very low compared to other scientific-grade CCDs, so the resulting image S/N ratio is very good.

Model G2-0402

G2-0402 model uses 0.4MPx OnSemi KAF-0402ME NABG Full-Frame CCD chip.

Resolution 768 (H)נ512 (V) pixels
Pixel size 9μm (H)נ9μm (V)
Imaging area 6.9mm (H)נ4.6mm (V)
Full well capacity ~100,000 e-
Output node capacity ~220,000 e-
Anti-blooming gate No
Dark current 1 e-/s/pixel at 0C
Dark signal doubling temperature 6.3C

KAF-0402ME CCD chip specifications

KAF-0402ME CCD chip and its Quantum Efficiency

Model G2-1600

G2-1600 model uses 1.6 MPx OnSemi KAF-1603ME NABG Full-Frame CCD chip.

Resolution 1536 (H)נ1024 (V) pixels
Pixel size 9μm (H)נ9μm (V)
Imaging area 13.8mm (H)נ9.2mm (V)
Full well capacity ~100,000 e-
Output node capacity ~220,000 e-
Anti-blooming gate No
Dark current 1 e-/s/pixel at 0C
Dark signal doubling temperature 6.3C

KAF-1603ME CCD chip specifications

KAF-1603ME CCD chip and its Quantum Efficiency

Model G2-3200

G2-3200 model uses 3.2 MPx OnSemi KAF-3200ME NABG Full-Frame CCD chip.

Resolution 2184 (H)נ1472 (V) pixels
Pixel size 6.8μm (H)נ6.8μm (V)
Imaging area 14.9mm (H)נ10mm (V)
Full well capacity ~55,000 e-
Output node capacity ~110,000 e-
Anti-blooming gate No
Dark current 0.8 e-/s/pixel at 0C
Dark signal doubling 6C

KAF-3200ME CCD chip specifications

KAF-3200ME CCD chip and its Quantum Efficiency

Model G2-8300

G2-8300 camera uses 8 MPx OnSemi KAF8300 ABG Full Frame CCD detectors with 4/3 format.

Resolution 3358 (H)נ2536 (V) pixels
Pixel size 5.4μm (H)נ5.4μm (V)
Imaging area 18.1mm (H)נ13.7mm (V)
Full well capacity ~25,000 e--
Anti-blooming gate 1000
Dark current 0.2 e-/s/pixel at 0C
Dark signal doubling temperature 5.8C

KAF-0402ME CCD chip specifications

KAF8300 CCD chip and its Quantum Efficiency

Model G2-2000

G2-2000 model uses 2MPx OnSemi ABG Inteline-Transfer KAI-2020 CCD chip.

Resolution 1604 (H)נ1204 (V) pixels
Pixel size 7.4μm (H)נ7.4μm (V)
Imaging area 11.9mm (H)נ8.9mm (V)
Full well capacity ~40,000 e-
Anti-blooming gate 300
Dark current 0.3 e-/s/pixel at 0C
Dark signal doubling 7C

KAI-2020 CCD chip specifications

KAI-2020 CCD chip and its Quantum Efficiency

Model G2-4000

G2-4000 model uses 4MPx OnSemi ABG Inteline-Transfer KAI-4022 CCD chip.

Resolution 2056 (H)נ2062 (V) pixels
Pixel size 7.4μm (H)נ7.4μm (V)
Imaging area 15.2נ15.3mm
Full well capacity ~40,000 e-
Anti-blooming gate 300
Dark current 0.3 e-/s/pixel at 0C
Dark signal doubling 7C

KAI-4022 CCD chip specifications

KAI-4022 CCD chip and its Quantum Efficiency

Camera Electronics

16-bit A/D converter with correlated double sampling ensures high dynamic range and CCD chip-limited readout noise.

Fast USB interface ensures image download time within seconds. Maximum length of single USB cable is 5m. This length can be extended for instance to 10m by using single USB hub or USB active extender cable.

Connection to practically unlimited distance can be achieved with the Gx Camera Ethernet Adapter device, which allows connection to up to 4 Gx cameras through 1Gbps Ethernet interface and TCP/IP protocol.

Remark:

Stated values are valid for G2 cameras revision 4. Previous revisions could differ in some parameters. Refer to chapter “G2 Camera Revisions” for differences among individual revisions.

Some parameters (e.g. camera gain) are defined by the used system driver, so they depend on the version of actually used driver. If the Gx Camera Ethernet Adapter is used, system driver is defined by the firmware version of this device.

ADC resolution 16 bits
Sampling method Correlated double sampling
Read modes Preview mode
Low Noise mode
Horizontal binning 1 to 4 pixels
Vertical binning 1 to 4 pixels
Sub-frame readout Arbitrary sub-frame
Computer interface USB 2.0 High Speed
USB 1.1 Full Speed compatible

Camera electronics specifications

Image download time depends on the CCD chip used in particular camera model. Also the read noise depends on the chip as well as on the read mode.

  • Preview read mode provides system read noise approx. 1or2e- above CCD chip read noise.

  • Low Noise read mode is somewhat slower, but ensures system read noise roughly equal to the manufacturer-specified chip read noise.

Model G2-0402

Gain 1.5 e-/ADU (1נ1 binning)
2.0 e-/ADU (other binnings)
System read noise 15 e- RMS (Low Noise mode)
16 e- RMS (Preview mode)
Full frame download 0.7 s(Low Noise mode)
0.5 s(Preview mode)

G2-0402 electronics specifications

Model G2-1600

Gain 1.5 e-/ADU (1נ1 binning)
2.0 e-/ADU (other binnings)
System read noise 15 e- RMS (Low Noise mode)
16 e- RMS (Preview mode)
Full frame download 2.6 s(Low Noise mode)
1.8 s(Preview mode)

G2-1600 electronics specifications

Model G2-3200

Gain 0.8 e-/ADU (1נ1 binning)
1.3 e-/ADU (other binnings)
System read noise 7 e- RMS (Low Noise mode)
10 e- RMS (Preview mode)
Full frame download 5.5 s(Low Noise mode)
3.8 s(Preview mode)

G2-3200 electronics specifications

Model G2-8300

Gain 0.4 e-/ADU (1נ1 binning)
0.8 e-/ADU (other binnings)
System read noise 8 e- RMS (Low Noise mode)
9 e- RMS (Preview mode)
Full frame download 14.2 s(Low Noise mode)
9.8 s(Preview mode)

G2-8300 electronics specifications

Model G2-2000

Gain 0.5 e-/ADU (1נ1 binning)
0.8 e-/ADU (other binnings)
System read noise 7 e- RMS (Low Noise mode)
9 e- RMS (Preview mode)
Full frame download 3.1 s(Low Noise mode)
2.1 s(Preview mode)

G2-2000 electronics specifications

Model G2-4000

Gain 0.5 e-/ADU (1נ1 binning)
0.8 e-/ADU (other binnings)
System read noise 7 e- RMS (Low Noise mode)
9 e- RMS (Preview mode)
Full frame download 6.7 s(Low Noise mode)
4.5 s(Preview mode)

G2-4000 electronics specifications

Notes:

  1. Binning can be combined independently on both axes.

  2. Download times are valid for USB2.0 host and may vary depending on USB Hubs, host PC etc.

Chip Cooling

Regulated two-stage thermo-electric chip cooling up to 50C below ambient temperature with forced air cooling and +/-0.1C temperature precision ensure very low dark current for long exposures.

CCD chip cooling Thermoelectric (Peltier modules)
TEC modules Two stages
Max. Δ T 50C below ambient maximum
45C below ambient typical
Regulation precision 0.1C
Hot side cooling Forced air cooling (fan)

Chip cooling specifications

Fan and air output vents on the back side of the camera

Fan and air output vents on the back side of the camera

Notes:

  1. It is not recommended to cool the chip to the maximum temperature difference, else the camera cannot guarantee temperature stability when the ambient air temperature rises. It is usually practical to set the temperature so the cooling utilization varies around 90%. This provides enough reserve in cooling power to keep the CCD temperature even if the ambient temperature rises several degrees Celsius.

  2. Water-assisted cooling is available for all G2 cameras. Contact the manufacturer for details.

  3. The cooling performance depends on the environmental conditions and also on the power supply. If the power supply voltage drops below 12V, the maximum temperature difference is lower.

Cooling tab of the CCD Camera control tool in the SIPS software package

Cooling tab of the CCD Camera control tool in the SIPS software package

Mechanical Specifications

Compact and robust camera head measures only 114נ114נ65mm (approx. 4.5נ4.5נ2.6inches). A vatriant with internal filter wheel is thicker and measures 77.5mm (approx. 3 inches). The head is CNC-machined from high-quality aluminum and black anodized. The head itself contains USB-B (device) connector and 12VDC power plug. Integrated mechanical shutter allows streak-free image readout, as well as automatic dark frame exposures, which are necessary for unattended, robotic setups. Integrated filter wheel contains 5 positions for standard 1.25-inch threaded filter cells. A variant of filter wheel with 6positions for the same filters without cells (only a glass) is also available.

G2 camera without filter wheel, with internal filter wheel and with attached external filter wheel (left). USB connector is on left side and power connector on right side of the camera head.

Internal mechanical shutter Yes, blade shutter
Shortest exposure time 0.1 s
Longest exposure time Limited by chip saturation only
Internal filter wheel 5 positions for 1.25" threaded filter cells or for D31mm unmounted filters
6 positions for 1" or D26.5mm unmounted filters
Head dimensions 114mmנ114mmנ77.5mm (with internal filter wheel)
114mmנ114mmנ65mm (without filter wheel)
Back focal distance 29mm (with internal filter wheel)
16.5mm (without filter wheel)
33.5mm (with external filter wheel)
Camera head weight 1.15kg (with internal filter wheel)
1.05kg (without filter wheel)
1.95kg (with internal filter wheel)

Mechanical specifications

Remark:

Shortest exposure time 100ms is available on G2 cameras revision 3 and higher. Shortest exposure time of older revisions was 175ms.

Filter wheel with 6 positions cause vignetting (shielding of the detector corners) if large CCD detector is used.

Regardless if the camera is equipped with filter wheel or not, the front view dimensions are the same. Also mounting adapter holes are the same, so both camera variants are compatible with the same set of telescope/lens adapters.

G2 camera head front view dimensions

G2 camera head front view dimensions

If the internal filter wheel is missing, the only mechanical difference is a thinner front shell of the camera head. This naturally affects Back Focal Distance, but mechanical spacers, compensating for different BFD are available (see the system diagram in the “G2 Camera Overview” sub-chapter above).

Different Back Focal Distances of cameras without filter wheel and with internal/external filter wheel

Power supply

The 12VDC power supply adapter enables camera operation from arbitrary power source including batteries, wall adapters etc. Universal 100240VAC/5060Hz, 60W “brick” adapter is supplied with the camera. Although the camera power consumption does not exceed 30W, the 60W power supply ensures noise-free operation.

Camera head supply 12VDC
Camera power consumption 15W without cooling
40W with 100% cooling
Adapter input voltage 100-240VAC/50-60Hz
Adapter output voltage 12VDC/5A
Adapter maximum power 60W

Power supply specifications

Notes:

  1. Camera power consumption is measured on the AC outlet of the 12Vpower supply.

  2. The camera contains its own power supplies inside, so it can be powered by unregulated 12VDC power source the input voltage can be anywhere between 10 and 14V. However, some parameters (like cooling efficiency) can degrade if the supply drops below 11V.

  3. G2 CCD camera measures its input voltage and provides it to the control software. Input voltage is displayed in the Cooling tab of the CCD Camera control tool in the SIPS. This feature is important especially if you power the camera from batteries.

12VDC/5A power supply adapter for the G2 Camera

12VDC/5A power supply adapter for the G2 Camera

Warning:

The power connector on the camera head uses center-plus pin. Although all modern power supplies use this configuration, always make sure the polarity is correct if you use own power source.

Optional accessories

Camera head can be combined with various accessories according to the requirements of the target application (optical system, used filters, guiding, etc.).

Telescope Adapters

Various telescope and lens adapters for the G2 cameras are offered. Users can choose any adapter according to their needs and another adapters can be ordered separately.

It is possible to choose from the following telescope/lens adapters:

2" barrel adapter
Adapter for 2" focusers.

T-thread short
M42נ0.75 inner thread, 7.5mm thick.

T-thread with 55mm BFD
M42נ0.75 inner thread.
Preserves 55mm back focal distance.

M48נ0.75 thread short
M48נ0.75 inner thread, 7.5mm thick.

M48נ0.75 thread with 55mm BFD
M48נ0.75 inner thread.
Preserves 55mm back focal distance.

Pentax (Praktica) lens adapter
M42נ1mm inner thread.
Preserves 45.5mm back focal distance.

M68נ1 thread adapter
Adapter with inner thread M68נ1.

Canon EOS lens adapter
Standard Canon EOS bayonet adapter.

Canon EOS clip lens adapter
Canon EOS bayonet adapter with the possibility to insert “clip” filter.
Can be used on cameras with internal filter wheel only.

Nikon F lens adapter
Standard Nikon F bayonet adapter.

External Filter Wheels

When there is no filter wheel inside the camera head, all electronics and firmware, intended to control it, stays idle. These components can be utilized to control external filter wheel with only little changes. Also the camera front shell can be manufactured thinner, the space for filter wheel is superfluous.

G2 camera with External Filter Wheel, Off-Axis Guider and G1 Guiding Camera (left), opened external filter wheel case (right)

External filter wheels are described in detail here.

Off-Axis Guider adapters

The G2 off-axis guider (OAG) is designed to allow attachment of any guiding camera with 1.25" eyepiece nose, although the nose must be somewhat shorter to achieve focus. G0 cameras are designed to achieve focus with G2OAG and a special shorter version of 1.25" nose with C-mount thread is available for all G1 cameras. Any camera with CS-mount (short version of C-mount standard) can use this adapter to be attached to G2OAG.

Off-Axis guider adapters are available with M420.75mm (T-thread) or M480.75mm threads

Off-Axis Guider adapters are described in detail here.

Guiding cameras

G0 and G1 cameras are completely independent devices with their own USB connection to the host PC. They are mentioned here only not to omit an important part of the whole system.

G1-0301 standalone guiding/imaging camera is equipped with USB connection and standard “AutoGuider” port

G0 and G1 cameras can be used on the G2 OAG, on standalone guiding telescope or for any other imaging purpose, like Moon or planetary imaging etc. Both G0 and G1 camera can share the Gx Camera Ethernet Adapter with up to 3 other Gx cameras to be accessed over network.

G0 and G1 guider cameras are described in detail here.

Gx Camera Ethernet Adapter

Gx Camera Ethernet Adapter allows connection of up to 4 Gx cameras of any type on the one side and 1Gbps Ethernet on the other side. This adapter allows access to connected Gx cameras using routable TCP/IP protocol over practically unlimited distance.

The Gx Camera Ethernet Adapter is available in several variants, but their functionality is basically the same

Gx Camera Ethernet Adapter devices are described in detail here.

Software Support

Powerful SIPS (Scientific Image Processing System) software supplied with the camera allows complete camera control (exposures, cooling, filters) with automatic sequences and complete image calibration. SIPS also supports advanced tools like Image Add tool with automatic sub-pixel image alignment, (L)RGB Add tool, Image Blink tool, image filters and many more functions.

Scientific Image Processing System

SIPS software package is freely available for download from this www site.

Drivers for ASCOM standard as well as native drivers for third-party software are also available (e.g. TheSkyX, MaxIm DL, AstroArt, etc.). Visit the download page of this web site for current list of available drivers, please.

Automatic guiding

SIPS software package allows automatic guiding of the astronomical telescope mounts using separate guiding camera. Proper and reliable automatic guiding utilizing the computational power of Personal Computer (e.g. calculation of star centroid allows guiding with sub-pixel precision) is not simple task. Guiding complexity corresponds to number of parameters, which must be entered (or automatically measured).

The SIPS Guider toolwindow

The SIPS “Guider” toolwindow

The “Guiding” tool allows switching of autoguiding on and off, starting of the automatic calibration procedure and recalculation of autoguiding parameters when the telescope changes declination without the necessity of new calibration. Also swapping of the German Equatorial mount no longer requires new autoguider calibration. There is also a graph showing time history of guide star offsets from reference position in both axes. The length of graph history as well as the graph range can be freely defined, so the graph can be adjusted according to particular mount errors and periodic error period length. Complete log of calibration procedure, detected offsets, correction pulses etc. is also shown in this tool. The log can by anytime saved to log file.

An alternative to classic autoguiding is the inter-image guiding, designed for modern mounts, which are precise enough to keep tracking with sub-pixel precision through the single exposure, and irregularities only appear on the multiple-exposure time-span. Inter-image guiding then performs slight mount position fixes between individual exposures of the main camera, which eliminates “traveling” of the observed objects through the detector area during observing session. This guiding method uses main imaging camera, it does not use another guiding camera and naturally does not need neither OAG nor separate guiding telescope to feed the light into it.

Inter-image guiding controls in the Guiding tab of the Imager Camera tool window

Inter-image guiding controls in the Guiding tab of the Imager Camera tool window

Advanced reconstruction of color information of single-shot-color cameras

Color CCD detectors have red, green and blue filters applied directly on individual pixels (so-called Bayer mask).

Schematic diagram of color CCD detector with Bayer mask (left) and magnified crop of raw image captured by color camera (right)

Every pixel registers light of particular color only (red, green or blue). But color image should contain all three colors for every pixel. So it is necessary to calculate missing information from values of neighboring pixels.

There are many ways how to calculate missing color values from simple extending of colors to neighboring pixels (this method leads to coarse images with visible color errors) to methods based on bi-linear or bi-cubic interpolation to even more advanced multi-pass methods etc.

Bi-linear interpolation provides significantly better results than simple extending of color information to neighboring pixels and still it is fast enough. But if the telescope/lens resolution is close to the size of individual pixels, color artifacts appear close to fine details, as demonstrated by the image below left.

The above raw image with colors calculated using bi-linear interpolation (left) and the same raw image, but now processed by the multi-pass de-mosaic algorithm (right)

Multi-pass algorithm is significantly slower compared to single-pass bi-linear interpolation, but the resulting image is much better, especially in fine details. This method allows using of color camera resolution to its limits.

SIPS offers choosing of color image interpolation method in both “Image Transform” and “New Image Transform” tools. For fast image previews or if the smallest details are significantly bigger than is the pixel size (be it due to seeing or resolution of the used telescope/lens) the fast bi-linear interpolation is good enough. But the best results can be achieved using multi-pass method.

Shipping and Packaging

G2 CCD cameras are supplied in the foam-filled, hard carrying case containing:

  • Camera body with a user-chosen telescope adapter. The standard 2" barrel adapter is included by default. If ordered, the filter wheel is already mounted inside the camera head and filters are threaded into place (if ordered).

  • A100-240VAC input, 12VDC output “brick” adapter with 1.8m long power cable.

  • 5m long USB A-B cable for connecting camera to host PC.

  • USB Flash Drive with camera drivers, SIPS software package with electronic documentation and PDF version of User'sManual.

  • Aprinted copy of camera User'sManual

G2 CCD cameras are shipped in the foam-filled carrying case (left), larger case is used if camera is ordered with external filter wheel (right)

Image Galleries

G2-8300 Image Gallery

Example images captured with G2-8300 camera.

Object M42 “Great Orion Nebula”
Author Reinhold Wittich
Camera G2-8300
Filters LRGB, H-alpha, OIII and SII
Exposure more than 10 hours
Telescope 300mm Newtonian

Object “Elephant Trunk” nebula, part of nebulosity complex IC1396 in Cepheus
Author Martin Myslivec
Camera G2-8300
Filters H-alpha, OIII and SII
Exposure 28 hours
Telescope 300mm f/4.5 astrograph

Object “Flame” and “Horse Head” nebulae in Orion
Author Jan Camek
Camera G2-8300
Filters Astrodon Ha, Baader LRGB
Exposure 7.2 hours
Telescope 300mm f/2.9 astrograph

Object IC1805 nebula complex
Author Jan Camek
Camera G2-8300
Filters Astrodon Ha+OIII (bi-color)
Exposure 14 hours
Telescope 300mm f/2.9 astrograph

Object M33 “Triangulum galaxy”
Author Jan Camek
Camera G2-8300
Filters Astrodon Ha+OIII, Baader LRGB, IDAS LPS2
Exposure 12 hours
Telescope 300mm f/2.9 astrograph

Object M78 nebula
Author Jan Camek
Camera G2-8300
Filters Baader LRGB
Exposure 6.2 hours
Telescope 300mm f/2.9 astrograph

Object NGC2244 “Rosette” nebula
Author Jan Camek
Camera G2-8300
Filters Astrodon Ha 5nm, OIII 3nm (bi-color)
Exposure 9 hours
Telescope 300mm f/2.9 astrograph

Object NGC5128 “Centaurus A” galaxy
Author Jan Camek
Camera G2-8300
Filters Baader LRGB
Exposure 6.6 hours
Telescope 300mm f/2.9 astrograph

Object NGC6914 nebula complex
Author Jan Camek
Camera G2-8300
Filters Baader LRGB
Exposure 6 hours
Telescope 300mm f/2.9 astrograph

Object WR134, nebulosity around a Wolf Rayet star in Cygnus
Author Tommy Nawratil
Camera G2-8300 (LRGB + Hα + OIII filters)
Telescope 10inch f/4 Newton

Object NGC7000 “North America” a IC5070 “Pelican”
Author Ondrej Podlucky
Camera G2-8300 (+ narrow-band filters)
Exposure 43 hours (mosaic of two frames)
Telescope Borg 101ED + F4ED reducer

Object M8 “Lagoon”
Author David Kennedy
Camera G2-8300 (+ Ha, R, G, B filters)
Exposure 9.5 hours
Telescope Borg 60ED

Object IC1396 “Elephant'strunk”
Author Ondrej Podlucky
Camera G2-8300 (+ narrow-band filters)
Exposure 27 hours
Telescope Borg 101ED + F4ED reducer

Object Lambda Centauri region
Author David Kennedy
Camera G2-8300 (+ Ha, R, G, B filters)
Exposure 8.9 hours
Telescope 71fl miniBorg F/7.8

Object NGC6888 Crescent nebula
Author Jonas Fiedler
Camera G2-8300 (+ Ha, R, G, B filters)
Exposure 4.5 hours
Telescope Takahashi FSQ 106

Object NGC1499 California Nebula
Author Ondrej Podlucky
Camera G2-8300 (+ narrow-band filters)
Exposure 28 hours
Telescope Borg 101ED + F4ED reducer

Object NGC891
Author Stefano Campani
Camera G2-8300 with H-alpha and RGB filters
Exposure 6.4 hours
Telescope 24" (610mm) RNT Newton

Object NGC660
Author Stefano Campani
Camera G2-8300 with H-alpha and RGB filters
Exposure 10.6 hours
Telescope 24" (610mm) RNT Newton

Object IC348
Author Milo Hroch
Camera G2-8300
Telescope 200mm, f/2.9 astrograph (f/4 mirror + 0.73 ASA corrector)

Object NGC281 “Pacman nebula”
Author Milo Hroch
Camera G2-8300
Telescope 200mm, f/2.9 astrograph (f/4 mirror + 0.73 ASA corrector)

Object VdB14, VdB15
Author Milo Hroch
Camera G2-8300
Telescope 200mm, f/2.9 astrograph (f/4 mirror + 0.73 ASA corrector)

Object NGC7380 “Wizard nebula”
Author Milo Hroch
Camera G2-8300
Telescope 200mm, f/2.9 astrograph (f/4 mirror + 0.73 ASA corrector)

Object M31 “Andromeda galaxy”
Author Patrick Hochleitner and Dieter Beer
Camera G2-8300
Telescope Skywatcher BD 80ED + 0,85 flattener

Object NGC7023 “Iris Nebula”
Author Patrick Hochleitner a Dieter Beer
Camera G2-8300
Telescope Skywatcher BD 80ED + 0,85 flattener

Object IC5070 “Pelican Nebula”
Author Thomas Jger
Camera G2-8300
Telescope 12" (305mm) f/3.8 astrograph

Object M20 “Trifid”
Author David Kennedy
Camera G2-8300
Telescope Vixen VC200L with reducer

Object Comet C2009P1 Garradd and M71
Author Martin Myslivec
Camera G2-8300
Telescope 185mm f/3.9 astrograph

Object IC1396 “Elephant Trunk”
Author Martin Myslivec
Camera G2-8300 (+narrow-band filters)
Telescope 185mm f/3.9 astrograph

Object NGC5128 “Centaurus A”
Author David Kennedy
Camera G2-8300
Telescope Vixen VC200L with reducer

Object NGC6888 “Crescent Nebula”
Author Patrick Hochleitner and Dieter Beer
Camera G2-8300
Telescope Skywatcher BD 120ED + 0,85 flattener

Object M101
Author Christoph Gerhard
Camera G2-8300
Telescope 7-inch Maksutov

Object NGC6559
Author Resa Ghanawistschi
Camera G2-8300
Telescope Pentax 75SDHF

Object NGC7000 “North America”
Author Martin Myslivec
Camera G2-8300 (+ narrow-band filters)
Telescope 185mm f/3.9 astrograph

Object M101
Author Manferd Fischer
Camera G2-8300
Telescope ASA N8

Object IC405, IC410
Author Ondrej Podlucky
Camera G2-8300 (+ narrow-band filters)
Telescope Borg 101ED + F4ED reducer

Object NGC2237 “Rosette”
Author Ondrej Podlucky
Camera G2-8300 (+ narrow-band filters)
Telescope Borg 101ED + F4ED reducer

Object IC434 “Horse Head”
Author Ondrej Podlucky
Camera G2-8300 (+ H-alpha)
Telescope Borg 101ED + F4ED reducer

Object NGC2237 “Rosette”
Author Tsutomu Chikazawa
Camera G2-8300
Telescope Orion CT10 Newtonian

Object M1 “Crab Nebula”
Author Tsutomu Chikazawa
Camera G2-8300
Telescope Orion CT10 Newtonian

Object M33
Author Tsutomu Chikazawa
Camera G2-8300
Telescope Orion CT10 Newtonian

Object M51 “Whirlpool Galaxy”
Author Tsutomu Chikazawa
Camera G2-8300
Telescope Orion CT10 Newtonian

Object M81 “Boode Galaxy”
Author Tsutomu Chikazawa
Camera G2-8300
Telescope Orion CT10 Newtonian

Object NGC4725
Author Martin Myslivec
Camera G2-8300
Telescope 185mm f/3.9 astrograph

Object NGC891
Author Pavel Cagas
Camera G2-8300
Telescope 250mm f/5.4 Newton

Object M33
Author Martin Myslivec
Camera G2-8300
Telescope 185mm f/3.9 astrograph

Object NGC7000 “North America”
Author Martin Myslivec
Camera G2-8300
Telescope 185mm f/3.9 astrograph

Object “Cave Nebula”
Author Martin Myslivec
Camera G2-8300
Telescope 185mm f/3.9 astrograph

Object NGC6888 “Crescent” (bi-color)
Author Martin Myslivec
Camera G2-8300
Telescope 185mm f/3.9 astrograph

Object IC1396 “Elephant Trunk”
Author Martin Myslivec
Camera G2-8300
Telescope 185mm f/3.9 astrograph

Object “Omega Centauri” cluster
Author Robert Knox
Camera G2-8300
Telescope 110mm Borg ED

Object M8 “Lagoon Nebula”
Author Robert Knox
Camera G2-8300 (+ H-alpha)
Telescope 110mm Borg ED

Object Eta Cariane nebula
Author Robert Knox
Camera G2-8300 (+ H-alpha)
Telescope 110mm Borg ED

Object M106
Author Martin Myslivec
Camera G2-8300
Telescope 185mm f/3.9 astrograph

All images published with permission of their respective authors.

G2-2000 and G2-4000 Image Gallery

Example images captured with G2 KAI cameras.

Object M42 Orion Nebula
Author Samuele Gasparini
Camera G2-4000
Telescope SkyWatcher 80ED + 0.85 flattener

Object SH2 155
Author Marco Burali
Camera G2-4000 (H-alpha + OIII + RGB)
Telescope BRC 250 F5

Object NGC2903
Author Marco Burali
Camera G2-4000
Telescope Takahashi TOA 150 F7

Object Virgo Galaxy Cluster
Author Marco Burali
Camera G2-4000
Telescope Takahashi TOA 150 F7

Object NGC7380
Author Marco Burali
Camera G2-4000
Telescope Takahashi TOA 150 F7

Object IC1805
Author Marco Burali
Camera G2-4000
Telescope Takahashi TOA 150 F7

Object NGC884 a NGC869
Author Marco Burali
Camera G2-4000
Telescope Takahashi TOA 150 F7

Object Gama Cygni
Author Marco Burali
Camera G2-4000
Telescope Takahashi TOA 150 F7

All images published with permission of their respective authors.

G2-0402, G2-1600 and G2-3200 Image Gallery

G2 CCD cameras with KAF detectors are primarily intended for research work. They are only occasionally used for “aesthetics astrophotography”. Following examples represent both science observations and astrophotography images.

Astronomy research

G2 cameras are appreciated by both professional researchers and amateur astronomers involved in scientific observations. Here are only a few examples, chosen from huge amount of observations, be it extragalactic novae discovery, minor planet photometry and astrometry, variable star discovery and regular observations, exoplanet transit observations etc.

Object WASP 12b exoplanet transit observation
Author Pavel Cagas
Camera G2-3200
Telescope 250mm f/5.4 reflector

Only 0.8mmag RMS difference from ideal light cure

Object Two new novae in M81 galaxy discovered within three days
Author Pavel and Petr Cagas, Vaclav Pribik
Camera G2-3200
Telescope 265mm f/8 reflector

This discovery is a record in the size of telescope, used to discover nova in M81. The second smallest has 750mm diameter.

Object New discovery of HADS (High Amplitude Delta Scuti) variable star
Author Vaclav Pribik
Camera G2-1600
Telescope 254mm f/4.7 reflector

Object 5 new variable stars discovered during HAT-P 20b exoplanet transit observations
Author Vaclav Pribik
Camera G2-1600
Telescope 254mm f/4.7 reflector

Object 9 novae in M31 galaxy
Author Kamil Hornoch
Camera G2-3200
Telescope 650mm f/3.6 reflector

Object Minor planet 2007/TU24 passing close to Earth
Author Peter Kusnirak
Camera G2-3200
Telescope 650mm f/3.6 reflector

Microscopy and material science

Object Solar cell sample visible light
Author Faculty of Electrical Engineering and Communication, Brno University of Technology
Camera G2-3200

Object Solar cell sample near IR, conductive direction
Author Faculty of Electrical Engineering and Communication, Brno University of Technology
Camera G2-3200

Object Solar cell sample near IR, micro-plasmas in barrier direction
Author Faculty of Electrical Engineering and Communication, Brno University of Technology
Camera G2-3200

Near-IR radiation of semiconductor (solar cell) samples

Object Palladium layer on the tungsten sample covered by tungsten oxide
Author J. Heyrovsk Institute of Physical Chemistry
Camera G2-0402

Field emission microscope images, camera field of view is 800nm (1.5nm/pixel).

Astrophotography

Object M57 "Ring" nebula
Author Pavel Cagas
Camera G2-3200
Telescope 265mm f/8 Newtonian

Object M27 "Dumbbell" nebula
Author Pavel Cagas
Camera G2-3200
Telescope 265mm f/8 Newtonian

Object M101 galaxy
Author Martin Myslivec
Camera G2-3200
Telescope 185mm f/3.9 astrograph

Object M66 galaxy
Author Pavel Cagas
Camera G2-1600
Telescope 265mm f/8 Newtonian

Object Comet "Holmes"
Author Pavel Cagas
Camera G2-1600
Telescope 265mm f/8 Newtonian

Object Globular cluster M13
Author Pavel and Petr Cagas
Camera G2-3200
Telescope 265mm f/8 Newtonian

Object M81 "Boode galaxy"
Author Pavel and Petr Cagas, Vaclav Pribik
Camera G2-3200
Telescope 265mm f/8 Newtonian

Object M16 "Eagle nebula"
Author Pavel and Petr Cagas
Camera G2-3200
Telescope 265mm f/8 Newtonian

Object M51 "Whirlpool galaxy"
Author Pavel and Petr Cagas
Camera G2-3200
Telescope 265mm f/8 Newtonian

Object M1 "Crab nebula"
Author Pavel Cagas
Camera G2-3200
Telescope 265mm f/8 Newtonian

All images published with permission of their respective authors.