{"product_id":"santa-barbara-scientific-sm-4-seeing-monitor","title":"Santa Barbara Scientific SM-4 Seeing Monitor","description":"\n\u003cul class=\"DAV-feature-list\"\u003e\n    \u003cli\u003e\n        High-sensitivity QHY CMOS sensor with ultra-low noise\n    \u003c\/li\u003e\n    \u003cli\u003e\n        Precision Kowa 100 mm f\/2.8 lens for accurate seeing measurement\n    \u003c\/li\u003e\n    \u003cli\u003e\n        Real-time FWHM data and 12-hour seeing graph logging\n    \u003c\/li\u003e\n    \u003cli\u003e\n        Weatherproof enclosure with USB 3.0 or Ethernet (EX model) connection\n    \u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n    \u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n    \u003cli\u003eSpecifications\u003c\/li\u003e\n    \u003cli\u003eIn the Box\u003c\/li\u003e\n    \u003cli\u003eDownloads\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n    \u003cli class=\"active\"\u003e       \n        \u003cdiv\u003e\n            \u003c!-- Title image text --\u003e\n            \u003cdiv class=\"DAV-bg-light\"\u003e\n                \u003c!-- Main Image --\u003e\n                \u003cdiv class=\"DAV-section-center\"\u003e\n                    \u003ch2\u003eSM-4 Seeing Monitor – Precision Astronomical Seeing Measurement\u003c\/h2\u003e\n                    \u003cp\u003eThe SM-4 Seeing Monitor from SBS is a dedicated tool for measuring atmospheric seeing conditions with precision. Designed for both professional observatories and serious astrophotographers, the SM-4 helps determine when conditions are suitable for high-resolution imaging. By continuously monitoring and recording image motion from Polaris, it provides real-time seeing data in arcseconds, allowing users to plan observing sessions based on objective sky conditions.\u003c\/p\u003e\n                \u003c\/div\u003e\n            \u003c\/div\u003e\n\n     \u003c!-- image text --\u003e\n            \u003cdiv class=\"DAV-section-container\"\u003e\n                \u003c!-- Image Section --\u003e\n                \u003cdiv class=\"DAV-section-img\"\u003e\n                    \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SBS-SM-4-Camera-Optics.png?v=1752113166\" alt=\"SM-4 Camera and Optics\"\u003e\n                \u003c\/div\u003e\n\n                \u003c!-- Text Section --\u003e\n                \u003cdiv class=\"DAV-section-text\"\u003e\n                    \u003ch3\u003eImaging System and Optics\u003c\/h3\u003e                \n                    \u003cp\u003e\n                        At the core of the SM-4 is the QHY5III462M CMOS camera, which features exceptionally high quantum efficiency (approximately 90 percent) and ultra-low read noise in the range of 1 to 3 electrons. This camera is paired with a Kowa 100 mm f\/2.8 C-mount lens, a high-quality Japanese optic known for sharpness and mechanical stability. Together, they capture 0.01-second exposures with sub-pixel centroid accuracy, making the system well suited for tracking subtle atmospheric distortions.\n                    \u003c\/p\u003e\n                    \n                \u003c\/div\u003e\n            \u003c\/div\u003e\n\n     \u003c!-- image text --\u003e\n            \u003cdiv class=\"DAV-section-container\"\u003e\n                \u003c!-- Image Section --\u003e\n                \u003cdiv class=\"DAV-section-img\"\u003e\n                    \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SBS-SM-4-Enclosure.jpg?v=1752113297\" alt=\"SM-4 Enclosure\"\u003e\n                \u003c\/div\u003e\n\n                \u003c!-- Text Section --\u003e\n                \u003cdiv class=\"DAV-section-text\"\u003e\n                    \u003ch3\u003eEnclosure and Mounting\u003c\/h3\u003e                \n                    \u003cp\u003e\n                        The SM-4 is enclosed in a weather-resistant aluminum housing with an optical-grade protective window. The design is intended for permanent outdoor installation. The lens can be focused manually, and fine pointing adjustments are made without moving the main enclosure. A USB 3.0 connection ensures fast data transfer to a connected PC. The overall design eliminates the need for telescope mounts or automated domes.\n                    \u003c\/p\u003e\n                    \n                \u003c\/div\u003e\n            \u003c\/div\u003e\n\n     \u003c!-- image text --\u003e\n            \u003cdiv class=\"DAV-section-container\"\u003e\n                \u003c!-- Image Section --\u003e\n                \u003cdiv class=\"DAV-section-img\"\u003e\n                    \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SM-4-Seeing-Graph.png?v=1752113425\" alt=\"SM-4 Seeing Graph\"\u003e\n                \u003c\/div\u003e\n\n                \u003c!-- Text Section --\u003e\n                \u003cdiv class=\"DAV-section-text\"\u003e\n                    \u003ch3\u003eSIMM Method and Data Collection\u003c\/h3\u003e                \n                    \u003cp\u003eRather than relying on traditional Differential Image Motion Monitor (DIMM) techniques, which require a dual-aperture mask and moving telescope, the SM-4 uses a Single Image Motion Monitor (SIMM) approach. It continuously images Polaris, calculating the root mean square (RMS) motion of the star’s centroid over a set of 256 frames. This process takes about one minute and avoids mechanical tracking errors and internal tube currents.                    \u003c\/p\u003e                  \n                    \u003cp\u003eThe custom software developed by Dr. Alan Holmes corrects for Polaris’s slow drift across the field during the night and converts measurements to zenith FWHM seeing values using standard atmospheric models. Results are displayed in real time and logged to text files every five minutes in the SeeingMonitor directory. A live graph of the last 12 hours is updated continuously and can be accessed or posted to a website if needed.\u003c\/p\u003e\n                \u003c\/div\u003e\n            \u003c\/div\u003e\n\n            \u003cdiv class=\"DAV-section-container\"\u003e\n                \u003c!-- Image Section --\u003e\n                \u003cdiv class=\"DAV-section-img\"\u003e\n                    \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SBS-SM-4-EX.png?v=1752113551\" alt=\"SM-4 EX\"\u003e\n                \u003c\/div\u003e\n\n                \u003c!-- Text Section --\u003e\n                \u003cdiv class=\"DAV-section-text\"\u003e\n                    \u003ch3\u003eSM-4 EX Model for Remote Installations\u003c\/h3\u003e                \n                    \u003cp\u003e\n                        For installations where the monitor must be located far from the control computer, the SM-4 EX model integrates a USB 3.0 extender over Ethernet. This version includes a USB-to-Ethernet transmitter, a power supply, and an Ethernet-to-USB receiver unit built directly into the enclosure. The user provides a Cat6, Cat7, or Cat8 Ethernet cable of the required length. The system has been successfully tested up to 150 feet with Cat6 cable, providing reliable remote operation without signal degradation.\n                    \u003c\/p\u003e\n                    \n                \u003c\/div\u003e\n            \u003c\/div\u003e\n            \u003cdiv class=\"DAV-section-container\"\u003e\n                \u003c!-- Image Section --\u003e\n\n                \u003c!-- Text Section --\u003e\n                \u003cdiv class=\"DAV-section-text\"\u003e\n                    \u003ch3\u003eUse Cases and Application\u003c\/h3\u003e                \n                    \u003cp\u003e\n                        The SM-4 is ideal for permanent observatories, research facilities, and advanced amateur astronomers who need accurate and repeatable seeing data. It is equally valuable for mobile setups, helping to decide when to attempt long-exposure, high-resolution imaging and when to switch to wide-field or narrowband work. The seeing monitor identifies trends in atmospheric stability that are often missed by visual inspection alone or weather forecasts.\n                    \u003c\/p\u003e\n                    \n                \u003c\/div\u003e\n            \u003c\/div\u003e\n        \u003c\/div\u003e\n    \u003c\/li\u003e\n\n\n\n\n    \u003cli\u003e\n        \u003ctable class=\"DAV-specifications\"\u003e\n            \u003ctbody\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003eFocal Length\u003c\/p\u003e\n                    \u003c\/td\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003e100mm\u003c\/p\u003e\n                    \u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003eIntegrated Camera\u003c\/p\u003e\n                    \u003c\/td\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003eQHY5III462M\u003c\/p\u003e\n                    \u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003c!-- Add more rows as needed --\u003e\n            \u003c\/tbody\u003e\n        \u003c\/table\u003e\n    \u003c\/li\u003e\n    \n\n    \u003cli\u003e\n        \u003cul class=\"DAV-grid\"\u003e\n            \u003cli class=\"DAV-grid-item\"\u003e\n                \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Santa-Barbara-Scientific-SM-4-Seeing-Monitor.jpg?v=1752109910\" alt=\"SM-4 Unit\" class=\"DAV-img-box\"\u003e\n                \u003cdiv\u003e\n                    \u003cp class=\"DAV-item-title\"\u003eSM-4 Unit\u003c\/p\u003e\n                    \u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n                \u003c\/div\u003e\n            \u003c\/li\u003e\n            \u003c!-- Add more items as needed --\u003e\n        \u003c\/ul\u003e          \n    \u003c\/li\u003e\n    \n    \u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n            \u003cli class=\"DAV-grid-item\"\u003e\n                \u003ca href=\"download-link.pdf\" target=\"_blank\"\u003e\n                    \u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 512 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n                    \u003cdiv\u003e\n                    \u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n                \u003c\/div\u003e\n                \u003c\/a\u003e\n            \u003c\/li\u003e\n            \u003cli class=\"DAV-grid-item\"\u003e\n                \u003ca href=\"https:\/\/www.qhyccd.com\/download\/\" target=\"_blank\"\u003e\n                    \u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e                \u003cdiv\u003e\n                    \u003cp class=\"DAV-item-title\"\u003eDownload Camera Drivers\u003c\/p\u003e\n                \u003c\/div\u003e\n                \u003c\/a\u003e\n            \u003c\/li\u003e\n                      \u003cli class=\"DAV-grid-item\"\u003e\n                \u003ca href=\"http:\/\/www.sbscientific.com\/site\/assets\/files\/1056\/seeingmonitorinstaller.zip\" target=\"_blank\"\u003e\n                    \u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e                \u003cdiv\u003e\n                    \u003cp class=\"DAV-item-title\"\u003eDownload SM Software\u003c\/p\u003e\n                \u003c\/div\u003e\n                \u003c\/a\u003e\n            \u003c\/li\u003e\n\n            \u003c!-- Add more items as needed --\u003e\n        \u003c\/ul\u003e\n    \u003c\/li\u003e\n\u003c\/ul\u003e\n","brand":"Santa Barbara Scientific","offers":[{"title":"SM-4","offer_id":50145075790109,"sku":"SBS-SM-4","price":1849.0,"currency_code":"USD","in_stock":false},{"title":"SM-4 EX","offer_id":50145075822877,"sku":"SBS-SM-4-EX","price":2449.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Santa-Barbara-Scientific-SM-4-Seeing-Monitor.jpg?v=1752109910","url":"https:\/\/davidastro.com\/fr-us\/products\/santa-barbara-scientific-sm-4-seeing-monitor","provider":"David Astro","version":"1.0","type":"link"}