The new SBIG STF-8300M is the second generation of SBIG’s original ST-8300M, an immensely popular 8.3 megapixel monochrome CCD camera. Among the key second-generation updates is a 10 megapixel/second digitization rate for faster image downloads. A full high resolution STF-8300M image now downloads in less than one second, compared to the 7.7 seconds of the original ST-8300M.
Also included is a faster sampling speed and a full frame image buffer, resulting in higher quality images with fewer artifacts and cleaner FFT’s. User-selectable automatic image artifact repair, with eight levels of filtering, provides for cleaner images and less post processing required. However, with the extra-low dark current of the Kodak KAF-8300 sensor used in the STF-8300M, casual imagers may not need to perform any post processing at all. If you prefer, you can still download raw images for total control in post-processing. In addition, a user-rechargeable desiccant plug is now standard equipment.
The STF-8300 was engineered for beginning and advanced imagers who want a fast, compact, low noise camera with a generous field of view; imagers with short tube refractors; imagers with moderate size catadioptric telescopes under 14” in aperture; and imagers who want a similar field of view and image resolution as their DSLR camera, but with a cooled CCD sensor for better performance (higher sensitivity and lower noise). Optional integrated 5-position and 8-position filter wheels are available for tri-color imaging.
The STF-8300M is a camera only, and is not self-guiding like the dual chip SBIG cameras. For long exposure imaging, your scope has to be guided during the course of an exposure. The new STF-8300M can be paired with the optional new low profile, wide field off-axis guider (OAG8300), which allows self-guiding using an optional SBIG ST-i planet cam and autoguider. The OAG8300 is designed with a 7-element relay lens system that places the position of the optional guide camera to the side of the main camera and an optional filter wheel, which minimizes the impact on overall backfocus. The same lens system also acts as a 0.7x focal reducer that doubles the field of view of the guide camera compared to a typical off-axis system. The OAG adds only ¾ in. (19mm) backfocus to the camera and optional filter wheel. An optional spacer must be placed between the camera and guider to maintain the proper camera/guider focus points if no filter wheel is being used.
The Kodak KAF-8300 imaging sensor used in the STF-8300M has an array of 3326 x 2504 active pixels (8.3 megapixels total), each measuring 5.4 microns square. The imaging area is 17.96mm x 13.52mm and has a diagonal measurement of 22.5mm (a Four Thirds Format chip). This is about 1.6x the image area of an SBIG ST-10 and nearly the same area as the Research Series STL-4020M. With its relatively small pixels and large image area, the STF-8300M is ideal for wide field imaging with short focal length/fast focal ratio optics in its high resolution (unbinned) mode.
Binned 2x2 the pixels are 10.8 microns square and binned 3x3 they are 16.2 microns square. At 2x2 the array is still 2 megapixels and at 3x3 just under one megapixel. You can bin the pixels up to a maximum of 15x15. This feature makes it possible to match the camera’s pixel size to your seeing and scope, from a small refractor up to a large SCT.
The Kodak CCD sensor in the SBIG STF-8300M has both 1000x antiblooming and microlens technology to improve the effective Quantum Efficiency of the sensor, allowing it to be used in a wide variety of optical configurations. For more details, click on the “Microlens” icon above.
The small and light STF-8300M body has a 2” nosepiece for connection to your telescope. The nosepiece can be unthreaded to reveal standard female T-threads in the front plate of the camera body for connection to T-mount camera adapters. The STF-8300M is also compatible with both C-mount and standard 35mm Nikon SLR camera lenses.
A built-in mechanical even-illumination photometric shutter is included for automatic dark frames. This is a necessity for anyone operating remotely, even if remotely means only a few feet away from the telescope.
The STF-8300M has a 9-pin I2C port that allows the use of SBIG filter wheels having the same interface. The power and commands for the filter wheel all come from the camera through this port, so there are no other cables or power supplies needed to operate the filter wheel. Also, the same software that controls the camera also controls the filter wheel. Automatic RGB exposure sequences may be set or the user may control the filter wheel individually for each exposure.
Due to the large size of this imaging sensor in the STF-8300M, the typical 1.25” LRGB filters are too small to fully cover the sensor without some vignetting in the corners. This may be acceptable at f/7 or longer focal ratios, but at shorter focal ratios the effect can become an issue. For this reason SBIG offers optional 5-position and 8-position filter wheels that hold 36mm filters that will not vignette the sensor.
The STF-8300M has single stage thermoelectric cooling with an active fan. The STF-8300M reaches a maximum of -40 degrees C below ambient with air cooling only. Running at only 70% cooling power will maintain -36 degrees C below ambient. Because of the CCDs extraordinary low dark current, great temperature deltas are not required to achieve a dark current low enough that it becomes relatively insignificant compared to the background sky brightness.
The SBIG STF-8300M body has rack handles that make for easier and safer handling of the camera, particularly in cold weather when wearing gloves; a high-speed USB 2.0 interface port with a 15-foot USB cable (commonly available and relatively inexpensive third party USB extenders are available for cable runs up to several hundred feet); a 9-pin I2C bi-directional accessory port; a standard ST-4 type opto-isolated autoguider output port that allows the STF-8300M to be used as a guider for a larger camera; an internal shutter for automatic dark frames; a 2” nosepiece; T-threads for attaching to T-mount photo accessories; a 1/4”-20 thread side plate for tripod mounting; a universal 90-240VAC power supply with a remote on/off switch; a printed instruction manual; and a custom-designed carrying case with pre-cut foam for your camera and accessories.
A supplied CD-ROM has sample images and software for SBIG’s CCDOPS version 5 camera control software, Software Bisque’s CCDSoft Version 5 image processing/camera control software, and Software Bisque’s TheSky version 5, level II, planetarium program with telescope control for Windows. The camera is compatible with both Windows and Mac computer operating systems.
Detector specifications are as follows:
Detector: Kodak KAF-8300 monochrome with microlens.
Pixel Array: 3326 x 2504 pixels.
Pixel Size: 5.4 x 5.4 microns.
Total Pixels: 8,328,304 active (8.3 megapixels).
Full Well Capacity: ~25,500e-.
Dark Current: ~0.002e-/pixel/second at -10 degrees C.
Readout specifications are as follows:
Shutter: even illumination mechanical.
Exposure: 0.09 to 3600 seconds.
Correlated Double Sampling: yes.
A/D conversion: 16 bits.
A/D gain: 0.37e-/ADU.
Read noise: ~9.3e- RMS.
Binning modes: 1x1, 2x2, 3x3 . . . 15x15..
Pixel digitization rate: >10 megapixels per second.
Full frame download: >1 second.
Optical specifications with a 4” f/6 (610mm focal length) refractor, unbinned, are as follows:
Field of view: 73.94 x 98.21 arc minutes.
Pixel size: 1.77 x 1.77 arc seconds.
System specifications are as follows:
Standard cooling: single stage thermoelectric, active fan, -40° C from ambient maximum, air cooling only.
Temperature regulation: +/-0.1 degree C.
Power requirements: 12VDC, 3 amps maximum, power supply included.
Computer interface: USB 2.0.
Computer compatibility: all Windows 32 and 64 bit O/S, plus Mac OSX.
Physical specifications are as follows:
Optical head: measures 2” x 4” x 5” (50mm x 100mm x 127mm); weighs approximately 1.8 pounds/0.8 Kg.
Supplied mounting methods: T-thread, 2” nosepiece.
Back focus needed: 0.69”/17.5mm.