Articles

New cooled CMOS cameras C1+7000 and C2-7000 offer quite large pixels of 4.5 μm, especially compared to majority of other CMOS based cameras available. As CCD sensors, often employing much bigger pixels, are no longer available, even relatively small increase in pixel size of a CMOS sensor significantly increases some key parameters like dynamic range (pixel area and thus also a number of electrons each pixel can accommodate corresponds to the square of pixel dimension). (more...)

C1 cameras can be newly equipped with adapters for Canon EOS and Nikon bayonet photographic lenses in addition to already announced adapters with M42 × 0.75 (T-thread) and M48 × 0.75 threads with 55 mm Back Focal Distance. Similarly to threaded adapters, bayonet lens adapters are attached to combined M42 × 0.75/CS-mount adapter on the C1 camera body. So, they are not compatible with C1 cameras with CS-mount adapter only. (more...)

Small, uncooled CMOS cameras of the C1 series (as well as G1 series with CCD sensors) are traditionally equipped with CS-mount threaded adapter. This adapter allows usage of wide variety of CCTV lenses with CS-mount (and with the help of simple 5 mm thick ring also with C-mount). CS-to-1.25" barrel adapter, supplied with every camera, enables using of these cameras with virtually any telescope instead of standard 1.25" eyepiece. But 1" diameter of the CS-mount thread is a limiting factor for newly introduced C1-12000 camera with large sensor. So, new adapter, combining both CS-mount and T-mount threads, was introduced for all C1 cameras. (more...)

Gx Mark II cameras are available in many variants — individual G2, G3 and G4 series offer camera integration with internal or external filter wheels, Off-Axis Guider adapters, various threaded adapters as well as standard Canon EOS and Nikon lens bayonet adapters etc. One of the distinguishing feature of Mark II cameras is the telescope/lens adapter interface allowing precise adjustment of optical axis (sensor tilt). Despite the vast variability and many options, the Gx Mark II camera system was designed to maintain adapter-specified back focal distance of adjustable adapters on all camera variants. (more...)

G3 CCD cameras offer all essential astronomical camera features like great sensitivity, low noise, efficient and regulated cooling, robust design, rich set of accessories and software support and especially large sensor area for affordable price. And Mark II series of G3 cameras inherits all these features, but brings some significant enhancements, like much faster download speeds and adjustable (tiltable) telescope adapters. (more...)

G4 Mark II cameras inherited all proven design concepts and features from the previous generation, like precise electronics providing uniform frames and extremely low read noise, efficient regulated CCD cooling, reliable mechanical shutter, modular mechanical construction ensuring compatibility with wide variety of accessories including off-axis guider adapters, external filter wheels, Ethernet adapters, guiding cameras etc. But Mark II cameras bring some important enhancements, like much faster download speeds and adjustable (tiltable) telescope adapters. (more...)

The cooled G2 series Mark II CCD cameras were developed for imaging under extremely low-light conditions in astronomy, microscopy and similar areas. Design of this series inherits from earlier G2 Mark I cameras but brings some significant enhancements. G2 cameras employ precise electronics providing uniform frames and extremely low read noise limited only by CCD detector itself. Modular mechanical construction allows various camera variants to be combined with rich set of accessories, including telescope adapters, off-axis guider adapters, internal or external filter wheels, Ethernet adapters, guiding cameras etc. (more...)

Gx series of cooled astronomical cameras evolved through many revisions, each bringing improvements, new features or just more aesthetic design. We are proud these cameras are now used to capture state-of-the-art astrophotographs (just see our Gallery section) as well as to acquire professional-grade research data. Now we introduce redesigned cameras with important enhancements, so they deserve denotation Mark II. (more...)

Fast Newtonian telescopes provide excellent price/performace ratio. They offer greatest aperture for the money, because their optical design if very simple, elegant and efficient. When a Newtonian telescope is build from high quality component (Pyrex mirrors, carbon tube, robust mirror holders and focuser, ...), they are hard to beat by any other optical design. The only problem remains — parabolic mirror creates perfect image on the optical axis only, aberration called coma distorts the image as the field of view increases. Fortunately advanced refracting correctors eliminate this aberration and help to make Newtonian the perfect wide-field instrument. (more...)

While the Gx cameras are firmly attached to the telescope focuser in most cases, sometimes they are used with photographic lenses, which lack any means for attachment to the telescope mount. While the G2 camera body offers standard “tripod thread”, larger G3 and G4 models did not allow for such threaded hole due to internal arrangement of CCD cold chamber. But we slightly redesigned the G3 and G4 front shell as a response to request from our users and introduced two standard 1/4" threaded holes close to the edges of the camera top side. These holes can be used to attach new 1.75" dovetail adapter (Vixen standard) for safe attachment of camera head to almost any telescope mount. (more...)

It is always encouraging when we realize that our users love their Gx cameras, that they are not only satisfied with their state-of-the-art performance and functionality, but they also appreciate the industrial design and manufacturing quality. Still, many users, in particular among the amateur astronomer's community, appreciate also the aesthetics of their equipment — color anodized parts of mounts, telescopes or focusers are good examples. Despite the camera head dimensions and shape are constrained by its features, we always took care to achieve the clean and functional design. Now we decided to offer variants of our G2, G3, and G4 cameras with a slight color touch to allow users to unify the camera appearance with the rest of their setup. (more...)

The smallest XS variant of the external filter wheel for G2 cameras offers 7 positions for unmounted D36 mm filters. Because filters are further from the sensor in the case of external filter wheel compared to internal filter wheel, greater filter diameter allows usage of the G2-8300 camera with largest sensor within G2 series to be used with fast optics without vignetting. But other models of the G2 series contain smaller sensors and they can work D31 mm filters. A possibility to build a new variant of the XS external filter wheel for D31 mm filters occurred. Smaller filter diameter allows increasing of the number of filter positions from 7 to 8, despite the external filter wheel dimensions remain unchanged.. (more...)

The Gx Camera Ethernet Adapter allows connection of up to four Gx cameras of any type over an Ethernet. Because the communication is handled over the TCP/IP network, the distance between camera and the host PC is virtually unlimited. The Ethernet port of the adapter device can be attached to arbitrary WiFi bridge device to access attached cameras wirelessly. However, such solution needs another box (the Ethernet/WiFi bridge device) with another power supply etc. This is why the Gx Camera Ethernet Adapter firmware was extended with support for USB/WiFi interfaces. (more...)

While answers to many questions cannot be universally true, as it depends on who you ask, the answer to question “What is the optimal number of filter wheel positions?” is 7 for vast majority of users. Astrophotographers need Red, Green and Blue filters for true-color photography and narrow-band Hα, OIII and SII filters, plus one position for clear or luminance filter. Researchers could live with 6 positions for NUBVRI filters, but one spare position, which could be left clear, is often useful. (more...)

No optical setup is capable to cover really wide field of view without refracting correction elements. Even the best and most expensive APO refractors and RC reflectors need field-flatteners if a 50 mm diameter field has to be utilized. With a little exaggeration, spending money for premium optics, which must be corrected either way, is not necessary when much cheaper optics with a quality corrector provide the same results. And in reality well corrected Newtonian reflectors proved to be the best wide-filed, large-diameter telescopes available to amateurs. The trick is in the refracting correction element just in front of the camera, which eliminates the so-called “coma” aberration, inherent to simple parabolic mirrors. And the 3" Wynne coma correctors belong among the best available. (more...)

CCD dark current halves with every ~6°C, so keeping the CCD sensor at low temperatures is a key feature of scientific CCD cameras, allowing long exposures not ruined by excessive dark current. The CCD cooling can achieve up to 50°C below the ambient temperature, which leads to below-freezing temperatures of the sensor in all cases. This is why it is crucially important to place the cooled detector in the hermetically sealed chamber else it would be covered by the water ice within minutes. And the chamber must be dried by a desiccant, because even the residual humidity in the air is enough to create frozen ice patterns on the sensor, harming the images. New design of the desiccant containers of the Gx cameras allows more comfortable desiccant exchange and easier desiccant regeneration. Also a new variant of the container was introduced, designed to allow tool-less container replacement. (more...)

We are proud our company could provide feedback when OnSemi designed the new KAF-16200 CCD sensor. What is so special about this CCD? Simply put, it is designed to be the best possible sensor for vast majority of astrophotographers and astro-imaging enthusiasts around the world. While there are even greater detectors available, like KAF-16803 in the G4-16000 camera, such huge sensors require at last 3" focusers and field correctors to cover them with good quality image. As opposite, KAF-16200 in the newly introduced G3-16200 camera fits within the field of view of typical 2" focusers and optical correctors, used on absolute majority of amateur scopes. And at the same time it leaves almost no field of view area uncovered, so it allows capturing of really stunning wide field images. In association with great 16MPx resolution and 6μm pixels, low read noise and dark current, above average sensitivity and especially uniform and clean field of view, G3-16200 is an ultimate imaging camera for majority of amateur telescopes. (more...)

Dark current, injecting electrons into CCD pixels regardless if the sensor is illuminated or not, is the most important source of the unwanted signal. As the dark current is caused by random processes, it exponentially depends of the sensor temperature — typically the dark current is halved with temperature drop by every 5 or 7 degrees Celsius, depending on the particular sensor. While dark current can be to some extend removed from images during calibration (subtraction of the so-called “dark frame”), the random portion of the signal always remains in the image. This is why the CCD sensors in cameras intended for very low light imaging (and thus allowing for many minutes long exposures) are always cooled. Despite the inherent dark current of the OnSemi detectors, used in the Gx series of CCD cameras, is relatively small, sometimes the camera is used in hot environments and more effective cooling is required to lower the dark current. (more...)

Adapter complying to the newly emerging de-facto standard of the M48 × 0.75 thread, but preserving the 55 mm distance to focal plane similarly to M42 × 0.75 based T-thread, is available for G2 and G3 cameras. (more...)

G2 series of small format CCD cameras uses high sensitive, low noise OnSemi Full-Frame and Interline-Transfer CCD detectors. While high-speed USB 2.0 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. (more...)

All technical products undergo incremental refinements and numerous innovations affected also the cooled CCD cameras of the Gx series. Changes are only subtle from the outside point of view, despite a small facelift of the G2 camera head. Updates of the internal design are more significant, but key features like extremely low read noise, efficient cooling etc., which position Gx cameras on top among similar products, are of course remained. (more...)

Despite the fact that the G2 and G3 cameras share the same adapter mounting interface, Off-Axis guiders for G2 cameras with either M42 or M48 variant of mounting thread cannot be used with G3 cameras. The mirror reflecting light to guiding camera inside the G2 OAG is positioned too close to the optical axis that it partially shadows larger CCD detectors of G3 cameras. And G4 cameras use even greater detectors and their adapter mounting interface is also larger. Off-Axis guiders for G3 and G4 cameras have to be designed from the ground up to place the mirror feeding the guiding camera with light as close to the optical axis as possible on the one side, but not to cause vignetting (shield the main CCD detector) on the other side. (more...)

New autoguiding camera G1-0301 has the same resolution like the G1-0300 model, but it has bigger pixels and thus also bigger CCD detector. Greater detector area (6.5 × 4.9 mm compared to 4.9 × 3.7 mm) and especially 80% larger pixel area bring proportionally higher sensitivity compared to G1-0300. This is why G1-0301 can be used with guiding telescopes with long focal length and also with Off-Axis Guider adapters. (more...)

Several reviews of Gx CCD cameras appeared in both printed and online publications. The printed review of G2-8300 was published in the British Astronomy Now magazine, online site cloudynights.com published review of G4-16000 and external filter wheel. You can check them for yourselves. (more...)

Front-Illuminated Full-Frame CCD detectors suffer from kind of “visual memory effect”. Bright parts of the previously acquired image are visible as weak and blurred image on the following exposures, even if they are dark frames, taken with a shutter closed. This effect is called Residual Bulk Image (RBI) and it can harm long exposures, create false images of nebulae or traces of bright stars. It is possible to deal with RBI if we understand mechanisms behind this effect—we can adopt the observing program or it is possible to eliminate RBI by leveling the conditions within CCD using the near infra-red light flood before every exposure (IR preflash). (more...)

The G1 series of CCD cameras was extended with a new model G1-1200. The Sony ICX445 CCD detector, used in this camera, is produced using EXview HAD technology and offers high quantum efficiency, comparable to cameras employing much more expensive ICX285 CCD. The 1/3" detector format (4.9 × 3.6 mm) as well as small pixels (3.75 × 3.75 μm) suit to short focal length guiding telescopes. G1-1200 is also good for capturing Moon and planets. (more...)

Guiding of telescope mount is a necessity for really long exposures even if a high-quality mount is used and mass produced “cheap” mounts require guiding even for short exposures. Guiding camera repeatedly images a selected star or a star pattern. Computer calculates differences in measured position and performs slight corrections to the mount to compensate for mechanical irregularities and other factors, e.g. refraction. Guiding camera can be attached to separate guiding telescope or off-axis guider can be used to feed the guiding camera with the light gathered by the main telescope, used for imaging. If the guider camera uses the same optics as the main imaging camera, it is crucially important to divert the light for it before the light reaches the filters. Numerous filter has so low light transmission (e.g. photometric B or UV filters, narrow-band filters etc.), that they effectively disable guiding with the exception of a very few very bright stars. (more...)

Cooled CCD cameras of G4 series contain detectors with 36 × 36 mm area, which is 50% more than photographic “full-frame” format. G4 camera dimensions are the same like dimensions of G3 series, with the exception of camera head thickness—G4 cameras are somewhat slimmer, because they do not contain internal filter wheel. Also camera handling, software control, power supply and connection to the host PC using fast USB 2.0 interface is the same like in the case of G3 cameras. Filter wheel for 50 × 50 mm square filters (round filters of 50 mm diameter cause vignetting on such large CCD chips) cannot be placed inside the camera head due to limited space. But it is possible to connect external filter wheel for 5 large filters to the G4 camera, the camera head already contains connector for external filter wheel control. (more...)

Gx CCD cameras are available in many variants. There are small guiding and planetary G0 and G1 cameras, cooled G2 series, large format G3 and G4 series. G2, G3 and G4 cameras are provided without filter wheel and with internal or external filter wheel. These variants have different mechanical dimensions and naturally offer different back focal distance. (more...)

Cooled CCD cameras of G4 series contain detectors with 36 × 36 mm area, which is 50% more than photographic “full-frame” format. G4 camera dimensions are the same like dimensions of G3 series. Also camera handling, software control, power supply and connection to the host PC using fast USB 2.0 interface is the same like in the case of G3 cameras. Filter wheel for 50 × 50 mm square filters (round filters of 50 mm diameter cause vignetting on such large CCD chips) cannot be placed inside the camera head due to limited space. But it is possible to connect external filter wheels for 5 or 7 large filters to the G4 camera, the camera head already contains connector for external filter wheel control. (more...)