SBIG ST-7XMEI Series CCD Cameras

The Model ST-7XMEI is the same camera as the ST-7XME except that it has no internal guiding CCD and some extras and not included in order to keep the base price as low as possible. Both the ST-7XME and ST-7XMEI cameras use the same electronics and USB 1.1 interface that is as fast as some competitors' USB 2.0. Moreover, the USB 1.1 interface is easily extended up to several hundred feet with commonly available and relatively inexpensive USB extenders whereas USB 2.0 is not. As of March, 2006, both the single CCD and dual CCD models come with the Remote Guide Head port for attaching an external guiding head. For a comparison of the ST-7XME and ST-7XMEI please refer to the chart below.

Each imaging camera is furnished with the most complete compliment of software available from any manufacturer of astronomical imaging equipment. The software includes camera control, telescope control, image processing plus photometric and astrometric measurement functions. The software provided with SBIG equipment is unsurpassed in performance and ease of operation. Optional operating software can be expanded to include remote telescope control, a large stellar data base from the SAO catalog and Hubble Guide Star Catalog, plus a non-stellar data base from NCC, IC, PCC (Principle Galaxies Catalog), PK planetary nebulae, WDS (double star catalog), and GCVS (variable star catalog). Support for Windows, Mac and Linux are inlcuded.

The Model ST-7XE is widely used in astronomy for both high quality images and scientific applications. The pixel binning modes allow the user to match the pixel size to various focal lengths ranging from long focal length refractors and SCT's to short focal length camera lenses. The dual CCD structure allowed SBIG to design an Adaptive Optics system to work in conjunction with the ST-7XE and other SBIG self-guiding cameras in the ST line.

High Quantum Efficiency

Kodak's latest version of the CCD we use in the ST-7XME model camera is designated the KAF-0402ME. This CCD has the same array architecture as the KAF-0401E NABG with some improvements. Of greatest significance is the increased quantum efficiency due to the addition of a microlens array over the pixels and the use of MAR coated cover glass. The same kind of improvement has already met with great success in the ST-10XME camera. The peak quantum efficiency for the KAF-0402ME used in all three models of ST-7XME cameras is almost 85%. They are the most sensitive CCD camera in their class. The QE for the blue wavelength of 400 nm is 50% higher than that of the previous KAF-0401E CCD (increased from 30% to 45% absolute QE) and 15% higher in the red spectrum near H-alpha (increased from 72% to nearly 85% absolute peak QE).

The resulting high QE from UV to IR makes the ST-7XME perfect for imaging deep space objects such as dim galaxies and emission nebula. By fortunate circumstance, the peak QE occurs very near the H-alpha emission line at 656 nm, making this camera extraordinarily sensitive at this important wavelength. It could be said that this camera was "made for" capturing H-alpha! Previously, this level of QE was achievable only through the process of thinning the wafer and illuminating the image sensor from the backside. However, thinned, back-illuminated CCDs are very expensive, but with the KAF-0402ME, similar performance to a back-illuminated CCD is achieved with lower dark current and superior cosmetic specifications in a full frame front illuminated detector.

With our latest high speed electronics and USB interface, these ST-7XME cameras will download a full frame image in 1 second! Partial frames and focus mode will update faster than once per second. Imagine focusing in full frame mode. Kodak CCDs are well known for their low dark current and low noise characteristics. Additionally, the Standard and Deluxe models have superior cooling with a water assist ready heat exchanger built-in.

The KAF-0402E CCD, without microlens, is also available as an alternative to the microlens part for applications where a microlens may not be desired. The QE for the KAF-0402E CCD is essentially the same as for the previous KAF-0401E. The difference is the addition of greater static protection. The ABG version of this part, the KAF-0401LE remains unchanged. While we recommend that our customers select the ST-7XME for astronomy, we will continue to offer the ST-7XE NABG and ST-7XE ABG so long as Kodak continues to manufacture these varieties of the CCD.

Owners of ST-7XE cameras (USB interface and E detector) may upgrade to the new ME CCD. Owners of ST-7E cameras (parallel interface and E detector) may upgrade to the ME CCD only (keeping the parallel interface) for or upgrade to both USB interface and ME CCD at the same time. However, since we no longer make parallel electronics that support the E detectors, owners of the original ST-7 model camera (non-E detector) must also upgrade to USB electronics in order to support the ME CCD.

Improved Features and Options

Larger Built-In Tracking CCD: The TC-211 tracking CCD has been replaced with a larger TC-237H in the ST-7XME Standard and Deluxe models, as we have done in the ST-8/9/10/2000 cameras. The TC-237H array is 657 x 495 pixels at 7.4 microns. This is the same CCD used in our former $1300 ST-237A imaging camera and current $2300 STV autoguider. The TC-237H is 2.7X larger than the TC-211 CCD which means there is a more than double the chance you will find suitable guide stars anywhere you happen to be looking without having to hunt.

In the tracking configuration, the TC-237H CCD will normally be binned 2x2 for increased sensitivity. When binned 2x2 the field of view remains 2.7X that of the TC-211 however as the pixel size is increased to 14.8 microns. The user may also use the TC-237H CCD in high resolution (unbinned) mode if desired. ThsSky software from Software Bisque automatically generates finder charts showing the correct placement of the guiding CCD field of view relative to the imaging CCD's field of view. Using this tool to plan your nights imaging is a great compliment to the self-guiding cameras.

Of course, guiding with the TC-237H tracking CCD means that the imaging CCD spends 100% of its time and quantum efficiency gathering the image. You are not required to compromise by giving up half of the quantum efficiency or by making twice the exposure time as you might with other self-guiding designs.

Upgradeability: Each of the the ST-7XME models is upgradeable. This is particularly important to new buyers or anyone who wants to pay as they go. For example, the low cost ST-7XMEI can be upgraded with a built-in tracking CCD or a Class 1 imaging CCD. It can even be upgraded to an ST-8XE or ST-9XE at a later time. This allows the new user to get his feet wet without paying for a deluxe system all at once.

Improved Carrying and Storage Case: The Deluxe model ST-7XME camera includes the same high quality carrying and storage case as the rest of our ST line of cameras. This case is made for SBIG by Pelican. The custom cut foam securely holds the ST-7 camera and power supply with additional spots for accessories, cables, etc. The case is dust proof, water proof, crush proof and carries a lifetime guarantee from the manufacturer. This case is optional for the ST-7XME Standard and ST-7XMEI Models.

Optional Test Lens: To make testing of the camera easier we have designed an optional test lens that screws into the t-thread front end of the camera. This is a handy accessory for learning the various camera functions in the day time if you do not have a camera lens adapter.

Other Optional Accessories: The ST-7XME cameras support a variety of professional accessories. Each model contains a ROM programmed to support the CFW8A Color Filter Wheel for automatic RGB or LRGB imaging when attached to the camera. The CFW8A is a 5-posisiotn filter wheel designed to match the ST-7XME camera body in size, design and finish so that when it is attached, the camera and filter wheel become a single unit. In addition, the new CFW10, ten-position filter wheel is fully suooirted by the all new ST-7 cameras. The CFW10 uses the I2C port in the camera to receive power and control commands. The CFW10 is larger in diameter than the ST-7 camera body, but it is designed to introduce the least amount of back focus distance. When used as a replacement to the ST-7 camera's front plate, the CFW10 adds less than 0.6 inches of backfocus. This lets the user add camera lenses to the CFW10. Each model also has electronic relays built-in so that the cameras can be used as autoguiders for film astrophotography or for guiding other CCD cameras. The built-in TC-237H guiding CCD in the Standard and Deluxe models enables the use of both the AO-7 Adaptive Optics Device and the SGS Self-Guiding Spectrograph. The Self-Guiding Spectrograph was designed to give maximum resolution with the ST-7 camera. Several camera lens adapters are available from SBIG for attaching a variety of 35mm camera lenses directly to the ST-7 without the filter wheel for wide field imaging. Third party manufacturers support the ST-7XME and CFW8A color filter wheel combination with camera lens adapters as well.

The ST-7XMEI is the single sensor version with no internal guiding CCD. The imaging CCD is a Class 2 KAF-0402ME with no column defects and the same high QE as the most expensive model. The entry level price for the ST-7XMEI makes it an ideal way to get started with the most popular, and now the most sensitive, astronomical CCD camera in its class. This model is also intended for those who may already have a guiding solution such as the STV or another CCD camera. It is also an excellent TDI imager. For more details see Alan Holme's recent PDF application note on the subject of TDI imaging with the ST-7XMEI or ST-9XEI cameras. The CCD may be upgraded to a Class 1 on special order. A TC-237H tracking CCD, water cooling and custom case may also be added at any time.

Each ST-7XMEI Special camera system includes the following: