Our solar system has fascinated mankind for millennia. Astronomical research seeks answers to the big questions of our existence: how big is the universe? How did it form? Astronomers all over the world turn their eyes to the cosmos. But it’s not only huge space telescopes that provide amazing images. Small telescopes equipped with standard industrial cameras allow even home astronomy students to look farther afield and gain new insights. However, in addition to versatile camera software, the right sensor is also crucial for the quality of the images. Australian amateur astronomer Anthony Wesley found that IDS’ uEye XCP camera with Sony’s Starvis 2 sensor was the perfect choice for taking high-resolution images of nearby planets such as Venus, Mars, Jupiter and Saturn.
Astrophotography requires overcoming special challenges, both technical and natural. This is especially true for planetary images taken with telescopes. Firstly, the Earth’s atmosphere is constantly moving, creating turbulence that distorts the light coming from stars and planets. This so-called “seeing” phenomenon makes objects appear flickering and blurry, especially when observed with terrestrial telescopes. The blurring and distortion caused by atmospheric turbulence makes it difficult to capture detailed images.
Secondly, Earth’s atmosphere absorbs and scatters visible or shortwave blue light. Near infrared, on the other hand, scatters less, resulting in clearer and sharper images. This is especially important in areas where visibility is poor due to turbulence. In addition, infrared penetrates thin clouds and dust particles better than visible light. Astronomers can use NIR-sensitive cameras to peer behind these interstellar dust clouds and identify structures hidden in visible light. This is true, for example, of young stars and star-forming regions, which are often surrounded by dense dust clouds. But the same is true when photographing large planets like Saturn and Jupiter. The better a camera performs in the low-light range, the more information you can get from the image. Not to be overlooked: infrared is less affected by artificial light sources on Earth. This means that NIR-sensitive sensors provide better conditions for observing the sky even in areas with moderate light pollution.
application
This has resulted in an increased demand for cameras with especially high NIR sensitivity. In this context, amateur astronomer Anthony Wesley has studied the performance and suitability of IDS cameras of the XCP family with Starvis 2 sensors for planetary photography, with the conclusion that the IDS U3-38C0XCP-M-NO camera model with the IMX662 monochrome sensor delivers excellent results.
“The IDS camera is the imaging component of a telescope with an aperture of 415 mm and a focal length of 6000 mm,” he said, explaining the camera’s function. “The camera records one to two minutes of video of planets such as Jupiter and Saturn at about 60 frames per second in both visible and infrared light through interchangeable filters.”
To form a single optical unit that fits into the telescope’s eyepiece socket, Anthony Wesley screwed the IDS camera, filter wheel and Barlow lens directly onto it. The Barlow lens, located between the eyepiece and the telescope, extends the telescope’s focal length, increasing magnification without the need for an additional eyepiece. ” The standard C/CS distance was not required, so the IDS camera base was modified to allow it to be mounted at a lower distance,” he explains the design.
But what features make this camera especially suitable for this application? “ Light sensitivity far beyond that of the human eye – that’s what sensors with Sony’s Starvis 2 technology are known for,” sums up Jürgen Hejna, Product Manager uEye Cameras at IDS, summarizing the sensor’s power. For example, the U3-38C0XCP Rev.1.2 model with the 2.16 MPixel IMX662 rolling shutter sensor delivers excellent image quality with a very high dynamic range thanks to the pixel technology. The USB3 camera delivers 88 images per second and is particularly powerful in low-light applications where high sensitivity and low resolution are required. The 1/3-inch sensor also minimizes annoying reflections inside the camera thanks to a feature called “anti-reflective coating”.
For Anthony Wesley, the compact camera offers many advantages: “The compact and lightweight uEye XCP is ideal for amateur telescopes.” The uEye cameras are inexpensive but have almost all the features an amateur astronomer could want for this application.’ He was also impressed by the ease of integration of the IDS cameras with the IDS Peak software development kit: “I am the developer and maintainer of the IDS camera modules for the FireCapture software, which is very popular with amateur astronomers. The IDS modules are written in C with Microsoft Visual Studio and compiled into DLLs that can be easily loaded into FireCapture to make use of the full functionality of the software.’
Image Processing
The video segments captured using FireCapture are further processed using Autostakkert, a Windows software program that automatically aligns and combines images of the night sky. “The software combines and averages the individual images, correcting for blurring and distortions caused by the Earth’s atmosphere,” explains Anthony Wesley. These artifacts appear as blurring and image noise, which can obscure important details in the image. In astronomical imaging, deconvolution is used to optimize the image quality of telescope images and correct blurry or distorted images. In this case, the Astra Image and Registax software packages are used to deconvolve and sharpen the images. The next step is to correct for the rotation of the object of interest observed during the recording time. “For example, Jupiter rotates one degree every 90 seconds,” says Anthony. The Winjupos software is used for this purpose, which can be used to superimpose, derotate and align time-shifted images and videos, as well as to combine red/green/blue images into a single color image. “ The final image cleaning process is done using Gimp, where we post-process the video to compensate for the blurring effect of the Earth’s atmosphere, significantly reducing this effect and producing a sharp image of the subject,” Anthony summarises the final image processing process.
software
However, to ensure all this happens, perfect interplay between hardware and software is required. IDS cameras can be easily integrated using the IDS Peak software development kit (SDK). “ IDS Peak is perfectly matched to our hardware and enables 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 diverse application options,” emphasizes Damian Wang, Regional Sales Director at IDS. This makes it possible to use the extensive features of the FireCapture software, which was specially developed for astrophotography.
“With the uEye XCP models, we are not only offering something new in our product portfolio, but also becoming one of the pioneers on the industrial camera market once again. The modern sensor technology of these cameras guarantees high frame rates, extremely high image quality and impressive high sensitivity in the infrared range, even when used in low light conditions, such as for planetary photography. The components used here enable professional astronomers as well as amateur astronomers to capture very high-resolution images of celestial objects,” emphasizes Jürgen Hejna.
Anthony Wesley has been closely following the planet and the camera market for over 20 years. “Cameras and technology have evolved from the past in terms of NIR sensitivity and low noise, and the combination of uEye XCP technology and the Sony Starvis Type 2 sensor is undoubtedly one of the best currently available ,” he concludes.
Outlook
“Sony’s Starvis 2 sensor-based cameras will be popular among amateur astronomers in the planetary imaging community due to their high sensitivity, wide depth of field and low noise,” said Anthony Wesley. “ Especially in the NIR range of 700nm to 1000nm, they will enable very exciting research that will help us better understand other planets in our solar system.” But the camera’s applications are not limited to space. “ Many of the techniques used here can also be applied to other areas with similar challenges, such as underwater photography in low light,” The Australian newspaper recommends.
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IDS Image Development Systems, Inc.
