Moravian Instruments G2 Series Mark II, User Manual, Page: 21 / 42

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Moravian Instruments G2 Series Mark II User Manual Download Page 21

21

Cooling and power supply

Regulated thermoelectric cooling is capable to cool the CCD chip up to
50 °C below ambient temperature. The Peltier hot side is cooled by fan.
The CCD chip temperature is regulated with ±0.1 °C precision. High
temperature drop and precision regulation ensure very low dark current
for long exposures and allow proper image calibration.

The camera head contains two temperature sensors – the first sensor
measures directly the temperature of the CCD chip. The second one
measures the temperature inside the camera shell.

Figure 7: Back side of the G2 Mark II camera head contains vents for a fan, cooling
Peltir hot side

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

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Summary of Contents for G2 Series Mark II

Page 1: ...G2 Series Mark II Cooled CCD Cameras User s Guide ...

Page 2: ...zed for and should not be used within Life Support Systems without the specific written consent of the Moravian Instruments Product warranty is limited to repair or replacement of defective components and does not cover injury or property or other consequential damages Copyright 2000 2018 Moravian Instruments Moravian Instruments Masarykova 1148 763 02 Zlín Czech Republic phone 420 577 107 171 web...

Page 3: ...el G2 2000 17 Model G2 4000 17 Camera Electronics 17 Model G2 0400 18 Model G2 1600 19 Model G2 3200 19 Model G2 8300 19 Model G2 2000 19 Model G2 4000 19 Cooling and power supply 21 Power supply 22 Mechanical Specifications 24 Camera with Internal Filter Wheel 25 Camera with XS External Filter Wheel 27 Camera without filter wheel 28 Optional accessories 30 Telescope adapters 30 ...

Page 4: ...or variants 32 Gx Camera Ethernet Adapter 33 Adjusting of the telescope adapter 34 Camera Maintenance 37 Desiccant exchange 37 Exchanging the silica gel 38 Changing Filters 39 Opening the camera head 39 Changing the Whole Filter Wheel 40 Changing the Telescope Adapter 41 Power Supply Fuse 42 ...

Page 5: ...ecessity to invest into any 3rd party software package thanks to included free SIPS software package However ASCOM for Windows and INDI for Linux drivers shipped with the camera provide the way to integrate G2 camera with vast variety of camera control programs The G2 cameras are designed to work in cooperation with a host Personal Computer PC As opposite to digital still cameras which are operate...

Page 6: ...er networking device to the communication path Please note while the USB standard allows usage of cable no longer than approx 5 meters the TCP IP communication protocol used to connect the camera over the Ethernet adapter is routable so the distance between camera setup and the host PC is virtually unlimited The G2 cameras need an external power supply to operate It is not possible to run the came...

Page 7: ...7 camera with the telescope make sure the whole telescope mount setup is capable to track the target object smoothly during long exposures ...

Page 8: ...s and sizes Figure 1 G2 Camera Mark II without filter wheel left with Internal filter wheel middle and with attached External filter wheel right G2 camera model with Internal filter wheel accepts two sizes of filters Filter wheel with 5 positions for unmounted D31 mm filters or filters in 1 25 threaded cells Filter wheel with 6 positions for unmounted D26 mm or 1 filters There are two sizes of the...

Page 9: ... variants can be used with every detector For instance G2 8300 camera works with CCD measuring 22 7 mm diagonally Depending on the used optics f ratio 1 or even 1 25 filters can cause more or less significant vignetting when combined with such sensor Please note the camera head is designed to either accept Internal filter wheel or to be able to connect to the External filter wheel but not both If ...

Page 10: ...10 Figure 2 Schematic diagram of G2 camera system components ...

Page 11: ... to achieve proper back focal distance for cameras without filter wheel 10 1 75 dovetail rail for G2 camera head 11 Gx Camera Ethernet Adapter x86 CPU 12 Gx Camera Ethernet Adapter ARM CPU Camera Ethernet Adapter allows connection of up to 4 Gx cameras of any type on the one side and 1 Gbps Ethernet on the other side This adapter allows access to connected Gx cameras using routable TCP IP protocol...

Page 12: ...e charge to neighboring pixels when image is over exposed to ensure linear response to light through the whole dynamic range FF CCD detectors used for astrophotography are equipped with ABG to eliminate disrupting blooming streaks within field of view Cameras with Full Frame non ABG detectors are suitable for scientific applications where linear response is necessary for photometric applications i...

Page 13: ...anism is also known as electronic shuttering because it allows very short exposures and also digitization of the image without mechanically shielding of the detector from incoming light Also G2 cameras with IT CCDs are equipped with mechanical shutter because electronic shutter does not allow dark frame exposures necessary for proper image calibration etc The price for electronic shutter if lower ...

Page 14: ...22 KAI 4022 Resolution 1604 1204 1604 1204 2056 2062 2056 2062 Pixel size 7 4 7 4 μm 7 4 7 4 μm 7 4 7 4 μm 7 4 7 4 μm Sensor size 11 9 8 9 11 9 8 9 15 2 15 2 15 2 15 2 ABG Yes Yes Yes Yes Color mask No Yes No Yes Cameras with C suffix contain CCD detector covered with so called Bayer mask Color filters of three basic colors red green blue cover all pixels so every pixel detects only light of parti...

Page 15: ...ectors used in G2 cameras depends on the particular camera model Figure 5 Quantum efficiency of OnSemi CCD detectors used in G2 cameras Inherent dark current of these detectors is quite low compared to other CCD detectors suitable for scientific applications which results into very good signal noise ratio Figure 6 Dark current of some OnSemi CCD detectors used in G2 cameras ...

Page 16: ...a 13 8 9 2 mm Full well capacity Approx 100 000 e Output node capacity Approx 220 000 e Dark current 1 e s pixel at 0 C Dark signal doubling 6 3 C Model G2 3200 G2 3200 model uses 3 2 MPx CCD OnSemi KAF 3200ME Resolution 2184 1472 pixels Pixel size 6 8 6 8 μm Imaging area 14 9 10 0 mm Full well capacity Approx 55 000 e Output node capacity Approx 110 000 e Dark current 0 8 e s pixel at 0 C Dark si...

Page 17: ...oubling 7 0 C KAI 2020 CCD detector with color Bayer mask can be used in the G2 2000C camera Model G2 4000 G2 4000 model uses 4 MPx CCD MPx OnSemi KAI 4022 Resolution 2056 2062 pixels Pixel size 7 4 7 4 μm Imaging area 15 2 15 2 mm Full well capacity Approx 40 000 e Output node capacity Approx 80 000 e Dark current 0 3 e s pixel at 0 C Dark signal doubling 7 0 C KAI 4022 CCD detector with color Ba...

Page 18: ... noise 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 Binning can be combined independently on both axes Image download time and system read noise depends on the CCD chip used in particular camera model as well as on the camera read mode Preview read mode provides system read ...

Page 19: ...ownload time 1 95 s Low noise 1 39 s Preview Model G2 8300 Gain 0 4 e ADU 1 1 binning 0 8 e ADU other binnings System read noise 8 e RMS Low noise 9 e RMS Preview Download time 4 95 s Low noise 3 48 s Preview Model G2 2000 Gain 0 5 e ADU 1 1 binning 0 8 e ADU other binnings System read noise 7 e RMS Low noise 9 e RMS Preview Download time 1 06 s Low noise 0 73 s Preview Model G2 4000 Gain 0 5 e AD...

Page 20: ...n particular CCD sensor evaluated during camera design Actual read noise of different sensors varies within sensor manufacturing batch and also among various manufacturing batches The camera read noise is determined by the sensor itself and the camera manufacturer cannot affect it ...

Page 21: ...or long exposures and allow proper image calibration The camera head contains two temperature sensors the first sensor measures directly the temperature of the CCD chip The second one measures the temperature inside the camera shell Figure 7 Back side of the G2 Mark II camera head contains vents for a fan cooling Peltir hot side The cooling performance depends on the environmental conditions and a...

Page 22: ...for regulation Power supply The 12 V DC power supply enables camera operation from arbitrary power source including batteries wall adapters etc Universal 100 240 V AC 50 60 Hz 60 W brick adapter is supplied with the camera Although the camera power consumption does not exceed 55 W the 60 W power supply ensures noise free operation Warning The power connector on the camera head uses center plus pin...

Page 23: ...wer source the input voltage can be anywhere between 10 and 14 V However some parameters like cooling efficiency can degrade if the supply drops below 12 V G2 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 Fi...

Page 24: ...shutter Shortest exposure time 0 1 s Longest exposure time Limited by chip saturation only Internal filter wheel 5 positions for 1 25 threaded cells or for D31 mm unmounted filters 6 positions for D26 mm unmounted filters Head dimensions 114 114 77 5 mm Internal filter wheel 114 114 65 mm without filter wheel Back focal distance 33 5 mm base of adjustable adapters Camera head weight 1 15 kg with I...

Page 25: ... e g optical window covering the CCD cold chamber When the adjustable adapter base intended for camera with Internal Filter Wheel is mounted on camera without filter wheel the resulting back focal distance is only 21 mm Camera with Internal Filter Wheel Figure 9 G2 camera head front view dimensions ...

Page 26: ...26 Figure 10 G2 camera head with Internal Filter Wheel side view dimensions Figure 11 G2 camera head bottom view dimensions ...

Page 27: ...27 Camera with XS External Filter Wheel Figure 12 G2 camera head with External filter wheel front view dimensions Figure 13 G2 camera head with External filter wheel side view dimensions ...

Page 28: ...of all external filter wheels is identical Camera without filter wheel If the camera model intended for usage with External filter wheel is used without filter wheel at all two types of adjustable adapter bases can be used When a thin adapter base intended for camera with Internal filter wheel is used the back focal distance is only 21 mm Figure 15 Camera without filter wheel with thin adapter bas...

Page 29: ...wheel This means all adapters attached to this thick base keep the same 33 5 mm back focal distance like the camera with External filter wheel attached or camera with Internal filter wheel and thin adapter base Figure 16 Camera without filter wheel with thick adapter base ...

Page 30: ... bayonet standard Canon EOS lens adapter preserves 44 mm back focal distance Nikon F bayonet standard Nikon F lens adapter preserves 46 5 mm back focal distance Mark II adapters are attached either directly to the External filter wheel front plate or to the adjustable adapter base mounted on the camera head Off Axis Guider Adapter OAG G2 camera can be optionally equipped with Off Axis Guider Adapt...

Page 31: ...s OAG guider port is compatible with G0 and G1 cameras It is necessary to replace the CS 1 25 adapter with short 10 mm variant in the case of G1 cameras Because G1 cameras follow CS mount standard BFD 12 5 mm any camera following this standard with 10 mm long 1 25 adapter should work properly with the G2 OAG Figure 17 G2 OAG sectional rendering illustrating reflecting mirror Attaching camera head ...

Page 32: ...porting this standard Figure 18 1 75 bar for standard telescope mounts Camera head color variants Camera head is available in several color variants of the center plate Visit manufacturer s web pages for current offering Figure 19 G2 Mark II camera color variants ...

Page 33: ...n of up to 4 Gx cameras of any type on the one side and 1 Gbps Ethernet on the other side This adapter allows access to connected Gx cameras using routable TCP IP protocol over practically unlimited distance Figure 20 The Gx Camera Ethernet Adapter with two connected cameras ...

Page 34: ...cal axis and sensor plane Figure 21 Releasing of the pushing screw The Mark II camera telescope adapters are attached using three pulling screws As the adapter tilt is adjustable another three pushing screws are intended to fix the adapter after some pulling screw is released to adjust the tilt Warning Both pulling and pushing screws used on the G2 camera adapter are fine pitch M4 0 5 thread screw...

Page 35: ... screw means the distance between the adapter and the camera body increases The spring is designed to be strong enough to push the camera head from the adapter fixed on the telescope regardless of the camera orientation When all three pulling screws are fully tightened releasing of just one or two of these screws does not allow adapter to move or at last only very slightly thanks to deformation of...

Page 36: ... e g when camera is equipped with internal filter wheel or to the External filter wheel case G2 Mark II adapters are not mounted directly on the camera head Instead a tilting adapter base holding the circular spring is always used If the External filter wheel is used the adapted base is not necessary as the Mark II External filter wheel front plate is already designed to hold the spring and it als...

Page 37: ... silica gel desiccant is placed inside the camera head This cylindrical chamber is connected with the insulated cooled CCD chamber itself Warning High level of moisture inside the CCD cold chamber can cause camera malfunction or even damage to the CCD sensor Even if the frost does not create on the detector when the CCD is cooled below freezing point the moisture can be still present It is necessa...

Page 38: ...hole container can be unscrewed so it is possible to exchange silica gel without the necessity to remove the camera from the telescope Silica gel is held inside the container with a perforated cap This cap is also screwed into the container body so it is easy to exchange the silica gel inside the container after it is worn out or damaged e g by too high temperature etc The container itself does no...

Page 39: ...d screwed out without any tool The sealing cap as well as the tool less container are not supplied with the camera they are supplied only as optional accessory Figure 25 Optional cap standard container and the tool less variant of the container Changing Filters It is necessary to open the camera head to change filters or the whole filter wheel To open the head unscrew the six bolts holding camera ...

Page 40: ...n optical bar plugged into the electronics board It is not necessary to unplug these cables to change filters but if you unplug them take care to connect them again in the proper orientation Figure 26 Filters can be exchanged after removing of the camera front cover Changing the Whole Filter Wheel The whole filter wheel can be changed at once It is necessary to remove the front part of the camera ...

Page 41: ...sary to unscrew the three pulling screws The adapter then can be removed and replaced with another one Warning Both pulling and pushing screws used on the G2 camera adapter are fine pitch M4 0 5 thread screws not standard M4 thread ones Always use only screws supplied with the adapter using of normal M4 screws damages the adapter Always make sure to carefully locate the ring shaped spring prior to...

Page 42: ...g of inverted polarity power plug or against connecting of too high DC voltage above 15 V by a fuse If such event happens and the cooling fans on the back side of the camera do not work when the camera is connected to proper power supply return the camera to the service center for repair ...

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