SBIG STF-8300C OAG FW Package
SBIG is proud to introduce the new STF-8300, the first high speed 8300 camera with user-selectable automatic image processing! A few key updates include:
- 10 Megapixel/second digitization rate for faster image download (Full frame < 1 sec.)
- Faster sampling speed and full frame image buffer, resulting in higher quality images with fewer artifacts and cleaner FFT’s.
- Less post processing required (and with the extra low dark current of 8300 CCD casual imagers may not need to perform any post processing).
- User-selectable choice of automatic image artifact repair for cleaner images or raw images for total control in post-processing.
- Filter wheel spacer
- Off-axis guider
The new STF-8300M and STF-8300C cameras are updated, faster, versions of the popular ST-8300M and ST-8300C models. SBIG's new versions have a full frame image buffer and readout at 10Mhz for lowest noise, high resolution downloads in less than one second. The STF-8300 uses SBIG's traditional even-illumination (photmetric) shutter design and adds a user rechargeable desiccant plug similar to the proven ST, STL, and STX designs. Integrated 5-position and 8-position filter wheels are also available as well as a new integrated, low profile, wide field off-axis guiding accessory (OAG-8300 below) that, with the ST-i guider, turns the STF-8300 into a self-guiding camera.
Optional Nikon or Canon EOS lens adapters are available from SBIG for use with or without a filter wheel. The small light body without a filter wheel also accepts a c-mount lens adapter.
Based on Kodak's KAF-8300, 8.3 Mega-pixel, full frame CCD with 3326 x 2504 pixels at 5.4 microns, the SBIG STF-8300M mono version is ideal for both short fast optics in high resolution mode, or for longer focal lengths binned 2x2 or 3x3. The STF-8300C camera is best suited to shorter fast optics unbinned, or binned 2x2 or 3x3 for monochrome imaging. The monochrome CCD can be used with a filter wheel in any of several binning and partial frame modes for monochrome, color or narrowband imaging. 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. This feature makes it possible to match the pixel size to your seeing and scope, from a small refractor to a large SCT. On nights of less than good seeing, or when used at longer focal length scopes such as Schmidt-Cassegrains, the sensor can be binned at 2x2 or 3x3 in full frame mode to match the conditions while maintaining the full field of view of the CCD.
These frame and binning modes, coupled with the large sensor area and 8.3 megapixel array make the STF-8300 cameras extremely versatile and adaptable to a very wide variety of telescopes and conditions. For these reasons, plus the camera's small size and breakthrough price point, SBIG feels that the STF-8300 is an ideal camera for those stepping up to a cooled low noise astronomical CCD camera from a DSLR and a superb backup camera for even advanced users.
User Selectable Internal Image Processing
The STF-8300 and STT-8300 CCD cameras are the two first astro-cameras available from SBIG with the ability to automatically clean up raw images with user-selectable automatic image processing! By selecting the level of hot pixel removal or even column repair, users can obtain exceptionally clean and accurate images without additional processing.
To illustrate, the 30 second dark frames, below, were taken at room temperature to accentuate the number of warm pixels. The first frame is unprocessed, the second frame has a medium filter, and the third frame is the most aggressive filter.
Filter Wheels and Filters
SBIG offers 5-position and 8-position 36mm filter wheels with optional inserts for 1.25" and 31mm filters. These filter wheels plug directly into the I2C port on the camera for fully automatic operation and therefore do not require any separate power, USB or control cables.
Full sets of 36mm LRGB and Narrowband filter by Astrodon, Baader Planetarium and Astronomik are available for unvigntted imaging at any focal ratio. The filter wheels are compatible with both Nikon and Canon lens adapters as well as or new OAG-8300 Off-Axis Guider accessory.
SBIG's OAG-8300 turns any STF-8300 into a self-guiding camera system. The OAG-8300 is designed to work with either the 5-position or 8-position filter wheel. Color cameras, or monochrome cameras without a filter can also use the OAG-8300 with a spacer and the OAG-8300 is backward compatible with all ST-8300 models. What is unique about the SBIG OAG-8300 is the 7-element internal otpical design. The OAG contains relay optics that move the guide camera to the side of the imaging camera, and at the same time, a 0.7X reducer effectively doubles the field of view of the guider. SBIG knows that this design allows for a low profile between the camera and the telescope, reducing backfocus requirements, and at the same time, gives a wide field of view that offers mode guide stars for the guide camera.
A mechanical shutter is included to facilitate darkframes. This is a necessity for anyone operating remotely; even if remotely means a few feet away from the telescope. Since the early days of the original ST-7 camera, SBIG has been providing even-illumination in CCDs, something quite rare in other astrophotography cameras. "Even-illumination" indicates the shutter mechanism is designed to open and close so that is doesn't change the proportion of light falling on the sensor due to the shape or motion of the shutter itself. This is what one finds for instance with an iris type of shutter that opens-up starting at the center and closes over the center last. In the STF-8300, SBIG uses a simple and very robust shutter wheel with a fan-shaped aperture of the same design that we have employed in the ST series cameras for the past 15 years. The STF-8300 shutter sweeps over he CCD without leaving any area of the sensor exposed for a difference period of time than any other area. Another benefit of the rotating disk type of shutter is that it has only one moving part, the motor. These motors are extremely reliable and can operate for millions of exposures without failure. In 15 years with thousands of cameras in the field taking millions of exposures, this shutter design has proven itself better than we can describe. SBIG's design is accurate, proven and reliable, no question.
Even-illumination shutters, also known as photometric shutters because of the producion of flat frames in photometric quality. When taking twilight flats or any flat field image using short exposure times, this is tremendously crucial. The effect is demonstrated in the twilight flat field images shown below.
Solid Machined Construction
Although small and light, the SBIG STF camera is built to last. The front plate, main body and rear plate are each machined from solid aluminum block for maximum strength and then hard anodized over a special bead blasted finished for durability. Connector labels are laser etched and will never wear off.
Efficient TE Cooling
In SBIG's tests of production models, the camera reached a maximum of -40 degrees C below ambient in less than 3 minutes. It was allowed to stabilize and a few degrees were then given up for regulation with the camera running at only 80% TE cooling power to maintian -36 degrees C below ambient.
Because of this CCDs extraordinarily low dark current, great temperature deltas are not required to achieve a dark current low enough to become insignificant compared to the read noise and sky background. For example, in one of SBIG's tests, one 15 minute dark frame taken at the same temeprature. The total noise in the remaining image was ~15 electrons which included both dark current noise and read noise. This is exceptionally low.
Low Dark Current
According to Kodak, the dark current of the KAF-8300 is less than 200e- at 60 degrees C with a dark current doubling temperature of 5.8 degrees. This means that for approximately each 5.8 degrees C that one warms the CCD, the dark current is doubled and for each 5.8 degrees C one cools the CCD the dark current is halved. Extrapolating this to -10C, SBIG can calculate the maximum dark current observors can expect to find at that temperature. In fact, Kodak's specifications are usually very conservative when it comes to dark current, and this value can vary from chip to chip 50% or more and still remain within the allowed specification. When SBIG measured the 8300 CCDs, they found many to be less than half of Kodak's allowed spec. This is also typical of what they have seen in other Kodak CCDs. In SBIG tests, they saw the dark current in some samples to be as low as 0.01 electrons at -10C. These are extremely low dark current values for a full frame CCD. Even at zero degrees C the typical dark current is well below 0.2 electrons! At -10C the average of our current production units is around 0.04 electrons making it the lowest dark current of any camera currently made by SBIG.
High Quantum Efficiency
In the past of SBIG's manufacturing, one of the drawbacks in using sensors with small pixels and antiblooming structure has been the trade-off of some quantum efficiency. However, Kodak's microlens technology has largely made this trade-off a thing of the past. The KAF-8300 uses microlenses to focus more light on each pixel that would otherwise be lost due to the opaque antiblooming gate structure of the sensor. As a result, the KAF-8300 sensor can handle up to 1000X the full well saturation and at the same time this CCD has quantum efficiency comparable to that of a full frame sensor without ABG. Moreover, the QE curve for this full frame sensor has a peak in the middle of the visual spectrum and good sensitivity well into the red and near IR> The QE at the important wavelength of H-alpha is nearly 50%.
Linearity is a meaure of how flat the CCD response is to light with increasing exposure times. For instance, an ideal CCD will record exactly twice the signal in a 20 second exposure than it does in a 10 second exposure from a cosntant light source. This is particularly important in photometric studies where the CCD is used as a tool for measureing light at various wavelengths to determine the temperature of stars. The sample SBIG measured is about 10X better than Kodak's allowed specification, with a response that is within about 1% of linear.
The STF-8300 comes with its own universal AC power supply. This supply will operate from 100-240VAC and provides 12VDC at 3.75A to the camera. The STF-8300 also has a built-in voltage regulator and can therefore be powered directly from any unregulated 12V (10-14V) source such as a bettery for oepration in the field.
Standard (ST-4 pin compatible) Autoguider Port
The guider port on the STF-8300 is the same as on the other ST cameras, using a modular telephone type 6-pin jack to connect the STF-8300 to the user's mount when using the camera as an autoguider or in Track $ Accumulate Mode with mount corrections. The internal relays used in the STF-8300 are opto-isolated and no external relay box is required for any mount with this camera. The STF-8300 can guide or image. To guide and image at the same time, SBIG's solution is to add the OAG08300 and ST-i autoguider for complete self guiding capability.
The STF-8300 camera comes with the following accessories
- Mac software: Equinox Image and Equinox Pro.
- 32 bit and 64 bit window software:CCDDOPS, CCDSoftV5, The SkyV.5
- Pelican hard case.
SBIG's STF series is the super-charged cousin to the highly popular ST-8300 series. Sporting the same lightweight body with the addition of a rechargeable desiccant plug, the interior electronics have been given a complete overhaul. This sporty upgrade made by SBIG allows the STF to boast faster download times and greatly reduced noise for cleaner images.
Kiss lengthy post processing times goodbye! SBIG has dedicated great research in the STF's upgraded electronics that offer users eight levels of noise filtering. This specialized filtering effectively cuts down on bright pixels when capturing in the field meaning far less post processing time. With the right conditions post-processing may, in fact, become a thing of your past.
SBIG knows that timing is everything when working with CCD cameras. The STF-8300's lightning quick 10 MP/ second electronics give the observor speedy download times which helps to shorten imaging sessions, especially when stacking multiple short exposures. Often times, less than one second for a full frame exposure. Have the ability to capture multiple sky flats in a very short period of time. The STF-8300 camera electronics are USB 2.0 for fast download rates and rapid focus mode. The small light body accepts both c-mount and standard 35mm Nikon camera lenses. SBIG has also built in a mechanical shutter to assist in automatic dark frames. In addition to its imaging capabilities, the STF can also be used as a guider.
The STF camera series from SBIG is a step up from the previous ST camera series.
|Manufacturer||Santa Barbara Instrument Group (SBIG)|