The exceptionally low noise combined with high sensitivity of the simple and inexpensive QHY-CMOS cameras have made them the choice of many amateur astronomers for solar, lunar, and planetary photography, where stacking and processing a very high number of frames greatly improves the raw sum image ("Lucky Imaging"). With their low noise, the color cameras in particular are also suitable for EAA, i.e. Electronically Aided Astronomy, where the images are combined to a live image directly during the observation via LiveStacking. For this, the software Sharpcap is often used, which naturally supports the QHY cameras, too.
For a beginner, it can be confusing to choose the right camera to start with. We therefore advise you to proceed step by step, starting with the equipment that allows to track (guiding) a telescope mount in such a way that your first attempts will also show pinpoint star images.
Before deciding to buy a new camera, you should give some thought to the following points:
- Which are the preferred observing objects?
- Which sensor size do I need for this in combination with the telescope?
- Which pixel size suits my focal length and "seeing"? There is a helpful calculator site: astronomy.tools
- Should I work monochrome with filters or with a color camera (OSC - One Shot Color)?
- Which computer capacity is available?
- What is the budget?
Our recommendation for getting started: Guiding and planetary cameras
Guiding cameras for long exposures
For astrophotography with longer exposures, the guiding precision of the telescope mount is crucial. All mounts have some tracking error during the exposure, whether due to mount setup errors or other mechanical causes. This tracking error causes the stars on each shot to become distorted into dashes, which ultimately ruins the image.
The guiding camera, after selecting a suitable guide star - together with appropriate software - ensures that tracking errors of the mount are automatically corrected during exposure and the guide star stays centered on the sensor with sub-pixel accuracy. The guiding module can be connected to an external guiding scope (e.g. Baader Multi-Purpose Vario Finder 10x60 (single or with MQR-IV finder holder) (various versions available) or the or directly to the imaging telescope via a so-called QHY Off-Axis Guider (OAG) (various versions available) .
QHYCCD has a long history of developing and producing guiding cameras, and was the first to introduce low-cost CMOS technology - including many of the company's own patents - to amateur astronomy. Also, many of the higher-end QHYCCD cameras have a guiding interface that is compatible with the SBIG ST4 standard.
The camera can then be connected directly to the mount via the ST4 interface; the guiding software still runs on the PC connected via USB. This is interesting if the mount is not controlled via the PC anyway. For example, if the mount is also controlled from the laptop via the ASCOM interface, the guiding signals can also be sent via this connection, and the ST4 cable is not needed. The most widely used guiding software is PHD2.
For beginners we would like to introduce two inexpensive modules at this point:
The QHY 5L-II-M is a 1.2 megapixel guiding camera with very high sensitivity (even faint stars can thus be used for tracking) and a USB 2.0 interface. They are ideal for use as lightweight autoguiders or planetary cameras where short exposures are typical.
The second is the QHY 5-III-178M with a faster USB3.0 interface, which in addition to its guiding function can be used even better as a planetary camera for "lucky imaging" (sun, moon and planets) successfully because of the higher data rate.
The reason for recommending these two products is based on the basic requirements for a good guiding camera. It should have the following features:
- Small pixels. Smaller pixels result in higher resolution of the sensor, especially with short guide tube focal lengths and small apertures, which in turn relieve mechanical strain on the mount (size and weight of the guide tube). The QHY-5L-II-M and the QHY-5-III-178M have pixel sizes of 3.75 µm and 2.4 µm, respectively, quite small compared to many competitor cameras on the market.
- High sensitivity. Detecting and guiding to faint stars depends on the lens diameter of the guide scope (the larger, the fainter stars can be detected) and on the sensitivity of the sensor's pixels. The sensor of the QHY-5L-II-M has a quantum efficiency of 74%, and the QHY-5-III-178M uses a backside-illuminated sensor with a quantum efficiency of over 80%. With a suitable guide scope, both cameras can detect guide stars in the field of view, regardless of where the guide scope is pointed on the sky. Modern guiding software supports subpixel accuracy, so even a small guiding scope like the VarioFinder or the QHY MiniGuideScope is sufficient for large telescopes, the guiding accuracy is only limited by the air turbulence. An off-axis guider has the advantage that it sees the same image as the imaging camera and mechanical bending of the telescope during the night is not a problem, but it has a smaller field of view.
- Small and light weight. Both cameras have a diameter of only 25.4 mm and thus fit directly into any 1¼" eyepiece. The QHY-5L-II-M weighs only 51g, while the QHY-5-III-178M weighs 86 grams. The smaller the size and weight, the less mechanical stress is placed on the guide tube, focuser and mount.
- Both cameras are equipped with monochrome sensors, this is sufficient for a pure guiding function. The interface of the QHY-5L-II-M is USB 2.0, fast enough for guiding, while the QHY-5-III-178M has a faster USB 3.0 interface and can also be used as a monochrome solar, lunar and planetary camera due to the high frame rate.
- Cameras for "lucky imaging" of bright objects of the solar system. For beginners, photography of planets, the lunar surface and solar structures like sunspots is easier and more promising at the beginning, because the technical effort is much less complicated than in long exposures of deep sky objects. Since exposure times are very short in both guiding and lucky imaging, you can use one can for both applications. However, the module should then preferably have a fast USB 3.0 interface.
QHY 5-III Serie USB 3.0 Guiding and Planetary cameras:
The models of the are camera modules for solar, lunar and planetary photography (lucky imaging technique), as well as for guiding applications and partly work as cameras for deep sky photography for beginners with fast USB 3.0 data transfer.
We offer the following products of QHY 5-III series:
|Sensor size||11.3 x 7.1 mm||7.4 x 5 mm||11.2 x 6.3 mm||11.1 x 6.3 mm||5.6 x 3.2 mm||7.68 x 4.32 mm||5.6 x 3.2 mm|
|Effective Array||79 mm²||36 mm²||71 mm²||70 mm²||17 mm²||33 mm²||17 mm²|
|Resolution||1920*1200 (2,3 MP)||3072*2048 (6,3 MP)||3840*2160 (8,4 MP)||3.856*2.180 (8,4 MP)||1920*1080 (2,1 MP)||1920*1080 (2 MP)||1920*1080 (2,1 MP)|
|Pixel size||5,86 µm||2,4 µm||2,9 µm||2,9 µm||2,9 µm||4 µm||2,9 µm|
|Frame Rate||138 fps||50 fps||44 fps||41 fps||44 fps||96 fps||44 fps|
|ADC-Bit depth||12 bit||14 bit||12 bit||12 bit||12 bit||12 bit||12 bit|
|Full-Well capacity||32 ke-||15 ke-||12 ke-||32 ke-||12 ke-||8000 ke-||15,7 ke-|
The QHY-5-III series offer a choice of 7 models in total, counting mono and color versions. All offer variants of the Sony STARVIS™ or PREGIUS™ (QHY174) image sensors, designed for surveillance and industrial use.
Most of all, the models differ in sensor size, resulting in different fields of view, as can be seen with the moon and an exemplary telescope. Between sensors in the 16:9 video format, the QHY178 has a sensor in the classic 3:2 image format, the largest representative QHY174 has a rarer 16:10 format. The format, in combination with the resolution, defines the output format: for example, the QHY462 shoots in 1080p, the QHY485 even in 4K, while the QHY178 and QHY174 with digital crop offer the choice of several ratios, including 1:1, 6:5, 5:4, 4:3, 3:2, 16:10 and 2:1.
Sony STARVIS™ sensors stand for highly sensitive BSI sensors with rear integrated conductive tracks. These allow the area of the photodiode to be maximized in favor of the highest possible conversion rate (quantum efficiency). Sony PREGIUS™ sensors are characterized by a global shutter. Here, the sensor is read out completely, instead of the usual line-by-line readout in rolling shutter cameras. Motion artifacts can thus be excluded.
A special technical feature distinguishes the QHY462 and QHY485: Their sensors of a new generation feature a "Super High Conversion Gain" mode. The sHCG function allows the generation of a strong output signal at low illuminance and very low readout noise of less than one electron.
The QHY178 is the only one of the models to feature 14-bit analog-to-digital conversion on the hardware side and can thus natively discern 16384 brightness steps.
Which planetary cameras are particularly suitable for beginners?
In the color camera segment, we recommend two options:
The QHY 5-III-462 M/C CMOS Camera (various versions available) (various versions available) offers the highest frame rate with full HD resolution as a high-performance planetary camera and, as a special feature, outstanding sensitivity in the infrared spectrum. In addition, it has an excellent price-performance ratio.
It is two CMOS cameras in one. As usual, it can be used to take normal one-shot color images of the planets of the solar system (including the Sun and Moon). In addition, due to the extremely low readout noise, RGB images of brighter DeepSky objects can also be captured at shorter exposure times using the Lucky Imaging technique.
Based on the same Sony sensor technology, but with four times the area, the QHY485 expands the feature set quite significantly, with 4K resolution and the ability to expose a larger area of sky. The high-resolution 8.3MP camera offers 4K resolution and the ability to ecapture a wider field of view - even as an all-sky camera with the included fisheye lens.
The QHY 5-III-485C Planetary and All Sky Camera (#1931030 , € 395) does not have the sensitivity extended into the infrared part of spectrum, but with the sHCG mode it delivers raw images with exceptionally low readout noise (less than 1e-). The sensor and its electronics deliver frame rates of 18.5 frames (fps) and 16 bit data depth per second via USB 3.0 at full resolution, and even 44 frames per second at 8 bit data depth.
New in the portfolio of the manufacturer is the QHY-5-III-585C Planetary and Guiding Camera (#1931031, € 469,-) , which has the technical capabilities of the QHY-5-III-485C but extends it with the extended sensitivity in the infrared spectrum similar to the QHY-5-III-462C.
For those interested in mono cameras or potential filter users, the QHY 5-III-178M CMOS Camera (#1931024, € 375,-) is exciting. Its very fine resolution sensor positions itself between those of the QHY462 and QHY485 in terms of area and resolution, and allows the choice of multiple shooting ratios with only minimal reduction in resolution.
If you have a need for a fast reading full HD camera, but without the limitations of a Bayer color filter, the
QHY-5-III-200M Planetary- and Guiding camera (#1931035, € 365,-)
is an exciting mono alternative to the QHY-5-III-462C.