Through stardust with Starvis 2
Low-light industrial camera opens up new dimensions in planetary photography
Our solar system has fascinated mankind for thousands of years. Astronomical research is looking for answers to the big questions of human existence. How big is the universe? How did it come about? Astronomers all over the world are casting their gaze into space. However, it is not only giant space telescopes that provide spectacular images; smaller telescopes equipped with standard industrial cameras also allow amateur astronomers to look far and gain new insights. In addition to versatile camera software, the right sensors are crucial for the quality of the images; cameras with particularly high NIR sensitivity are in demand. Australian amateur astronomer Anthony Wesley considers the uEye XCP camera from IDS, equipped with Sony Starvis 2 sensors, to be an excellent choice for capturing high-resolution images of our neighboring planets such as Venus, Mars, Jupiter and Saturn.
Astrophotography has to overcome special challenges in two respects, both technical and natural. This applies in particular to telescopic images of planets. For one thing, the Earth's atmosphere is constantly in motion, creating turbulence that distorts the light coming from the stars or planets. This so-called "seeing" leads to a flickering or blurring of the objects, especially when observing through earthbound telescopes. This blurring and distortion caused by atmospheric turbulence makes it difficult to capture detailed images.
On the other hand, the earth's atmosphere absorbs and scatters visible or short-wave blue light. Near-infrared light, on the other hand, is scattered less, resulting in clearer and sharper images. This is particularly important in regions with poor "seeing" conditions caused by air turbulence. In addition, infrared light penetrates thin clouds and dust particles better than visible light. By using an NIR-sensitive camera, astronomers can look behind these interstellar dust clouds and recognize structures that remain hidden in visible light. This applies, for example, to young stars and star-forming regions, which are generally surrounded by dense dust clouds. But the same applies to capturing images of large planets such as Saturn or Jupiter: the more powerful the camera in the low-light range, the more informative the images will be. Not to be neglected: Infrared light is less influenced by artificial light sources on Earth. This means that NIR-sensitive sensors offer better conditions for sky observation even in areas with moderate light pollution.
Application
Cameras with particularly high NIR sensitivity are therefore in high demand. In this context, amateur astronomer Anthony Wesley has investigated the performance of IDS cameras from the XCP family with Starvis 2 class sensors and their suitability for planetary photography - with success: The IDS camera model U3-38C0XCP-M-NO, equipped with the monochrome IMX662 sensor, delivers outstanding results.
"The IDS camera is the imaging element for a telescope with an aperture of 415 millimeters and a focal length of 6000 millimeters," he explains the function of the camera. "It records one- to two-minute video segments of planets such as Jupiter and Saturn at a speed of around 60 frames per second through interchangeable filters, both in visible light and in the infrared range."
To form a single optical unit that fits into the eyepiece tube of the telescope, Anthony Wesley screwed the IDS camera, filter wheel and Barlow lens directly together. The Barlow lens between the eyepiece and the telescope extends the focal length of the telescope and thus increases the magnification without the need for an additional eyepiece. "The IDS camera base has been modified to allow mounting at a low distance, as I don't need the standard C/CS distance," he explains the design.
But what features made the camera stand out? "Light sensitivity that goes far beyond the human eye - that's what sensors with Starvis 2 technology from Sony stand for," says Jürgen Hejna, Product Manager uEye cameras at IDS, summing up the strength of the sensors. For example, the U3-38C0XCP Rev.1.2 model with the 2.16 MPixel IMX662 rolling shutter sensor uses pixel technology to achieve exceptional image quality with a particularly high dynamic range. The USB3 camera delivers a fast 88 images per second and is particularly strong in low-light applications where high sensitivity and low resolution are required. The 1/3" sensor also minimizes distracting reflections within the camera thanks to so-called "Anti Reflection Coating".
For Anthony Wesley, the compact camera has further advantages: "The compact, lightweight uEye XCP is well suited for amateur telescopes. The uEye cameras are inexpensive, but offer almost all the functions that amateur astronomers want for this application." He was also impressed by the easy integration of the IDS cameras via the IDS peak software development kit. "I am the developer and maintainer of the IDS camera module in the FireCapture software, which is popular with amateur astronomers. The IDS module is written in C with Microsoft Visual Studio and is compiled into a DLL that can be easily loaded into FireCapture to enable the use of the comprehensive software features.
The compact, lightweight uEye XCP is well suited for amateur telescopes. The uEye cameras are inexpensive, but offer almost all the functions that amateur astronomers want for this application.
Image processing
The video segments recorded using FireCapture are then processed using Autostakkert, a Windows software program that automatically aligns and merges the images of the night sky. "The software combines and averages the individual images and corrects blurring and distortion caused by the Earth's atmosphere," explains Anthony Wesley. This blurs can appear as blurring or image noise and obscure important details in the images. In astronomical imaging, the deconvolution method is therefore used to optimize the image quality of telescope images and to correct blurred or distorted images. In this case, the Astra Image and Registax software packages are used for deconvolution and image sharpening. In the next step, the observed rotation of the target object during the recording time must be corrected. "For example, Jupiter rotates by one degree every 90 seconds," explains Anthony. The Winjupos software is used for this, with the help of which time-shifted images and videos can be superimposed, derotated and adjusted, and red/green/blue images can be combined to form a color image. "The final image adjustment is done with Gimp. In this way, the post-processing of the video can compensate for the blurring effect of the Earth's atmosphere and drastically reduce it to produce a clear image of the target object," says Anthony, summarizing the final image processing procedure.
Software
To guarantee all this, however, a perfect interaction of hardware and software is required. The IDS cameras are easily integrated using the IDS peak software development kit (SDK). "IDS peak is perfectly matched to our hardware, allowing users to get the most out of our cameras. It includes programming interfaces and software tools that ensure an intuitive programming experience, quick and easy installation and versatile application possibilities," emphasizes Damien Wang, Area Sales Manager at IDS. This makes it possible to use the extensive features of the FireCapture software specially developed for astrophotography. "With the uEye XCP models, we are not only offering something new in our portfolio, but are also once again among the pioneers in the industrial camera market. The latest sensor technology in these cameras ensures high frame rates and remarkably high image quality - and impresses with its high sensitivity in the infrared range, even when used in low-light situations such as planetary photography. With the components used here, not only professional but also amateur astronomers are able to take particularly high-resolution images of celestial objects," confirms Jürgen Hejna.
Anthony Wesley has been observing planets and the camera market very closely for over twenty years. "Camera and sensor technology have taken an evolutionary step forward, both in terms of NIR sensitivity and lower noise behavior. The technology of the uEye XCP in combination with the Sony Starvis 2 sensors is undoubtedly one of the best currently available," he concludes.
Outlook
"Cameras based on the Sony Starvis 2 sensors will be popular with amateur astronomers in the planetary imaging community due to their high sensitivity, great depth of field and low noise," believes Anthony Wesley. "Especially in the NIR range between 700 nm and 1000 nm, where very interesting work can be achieved that will advance our understanding of other planets in our solar system." But the field of application of the cameras does not only extend into space. "Many of the techniques used can also be applied to other areas with similar challenges, such as underwater photography in low-light environments," recommends the Australian.
uEye XCP - the industry's smallest housing camera with C-mount
Model used: U3-38C0XCP-M-NO
Camera family: uEye XCP
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Client
Anthony Wesley is an amateur astronomer from Australia who specializes in video astronomy and low light photography of planets in the solar system. He has added support for several cameras from different camera manufacturers to FireCapture, one of the leading planetary capture tools, and rated the uEye+ XCP cameras outstanding. The uEye+ XCP cameras with the Sony Starvis 2 sensors have more than convinced Anthony Wesley.
