SBIG is regarded as the pioneering company of imaging and guiding products for the astronomy community. So while there are other cameras on the market that do planetary imaging and autoguiding, SBIG is providing a solution unsurpassed in both technology and value for both applications.
The innovative, eyepiece-size ST-i camera is aimed at both entry-level and advanced amateur astronomers. Unlike other autoguiding cameras, the ST-i includes a mechanical shutter, providing greater sensitivity and more accurate guiding as users can now automatically capture and use dark frames while autoguiding. The camera can take exposures as short as 0.001 seconds and focus at up to 21 frames per second. It will download 16-bit images at up to 12 frames per second, allowing users to extract finer detail with higher dynamic range than 8 bit cameras, especially when doing planetary imaging
Recognizing that many astronomers begin imaging with DSLR’s and video cameras, SBIG is also bundling the ST-i with a suite of powerful software that can be used by any imager regardless of whether they use a CCD camera or DSLR for imaging. The ST-i comes with fully functional versions of Software Bisque’s The SkyTM version 5 and CCDSoftTM, versions 5. Combined with SBIG’s own CCDOpsTM and PlanetMasterTM software for high resolution planetary imaging, this bundled suite of imaging and planetarium software provides customers with a powerful and comprehensive set of tools. The imaging software suite not only supports the planetary and autoguiding functionality of the ST-i but also provides a comprehensive planetarium, telescope control and image processing solution for users of DSLR’s and other astronomical imaging cameras.
If purchased separately, customers would pay a significant percentage of the price of the ST-i and imaging software just for similar software alone. Entry level and beginner astroimagers usually cannot afford to purchase such an extensive suite of software.
No other product offers such a comprehensive high performance autoguiding and planetary imaging solution at a comparable price.
The ST-i along with the bundled software provides a great entry-level product to the SBIG family, and are an ideal complement to SBIG’s popular ST-8300 CCD camera.
ST-i PLANET CAM AND AUTOGUIDER
- Low noise, high sensitivity CCD - Monochrome or Color
- Internal mechanical shutter for automatic dark frames
- Electronic shutter for short exposures
- Up to 21 frames per second in focus mode
- 16 bit A/D
- Eyepiece size body (1.25" diameter)
- Low cost
- Lightweight - only 2.2 oz.
- Powered from USB Port
- Standard Guider Output Port
- Front end threaded for standard 1.25" filters
- CCDOPS Autoguiding and Imaging Software with Planet MasterTM
- CCDSoftV5 Autoguiding and Imaging Software Software
The ST-i Planet Cam and Autoguider adds features unavailable elsewhere in a camera of this size and price. A high performance compact camera that is an excellent guider and very capable Planet Camera. The body is light weight, no larger than many 1.25" eyepieces. In fact, it is 1.25" in diameter, 3.5" long and weighs only 2.2 ounces. The camera receives both control signals and power from the USB port of your computer, so only one thin USB cable is required for using the camera as an imager. For guiding, a standard, opto-isolated, autoguider output port is located in the back panel (see below).
KODAK KAI-340 CCD - Mono or Color
Rather than using a low cost CMOS sensor (with high noise), the ST-i uses a high quality, low noise, Kodak CCD. The KAI-340 CCD has a measured read noise of only 9e- in the ST-i camera. This is the same CCD used as the guiding sensor in the new STX series cameras and the AllSky-340 cameras. The array is 648 x 484 pixels at 7.4 microns square. Anti-blooming is standard. We use only the Class 1 version of this CCD with 0 column defects, 0 cluster defects, 0 dead pixels, and 0 saturated pixels, all according to Kodak specifications. On-chip binning is available for 14.8u pixels if desired, and various sub-frame modes may be used to speed-up the focus and download rates. A full frame high res image will update at the rate of approximately 5 frames per second. In addition to full-frame, half-frame and quarter-frame modes, the user may select a sub-frame region of interest (ROI) of any size located anywhere on the CCD. In focus mode, using a 20 x 20 pixel box the update rate is greater than 20 frames per second. This sensor is available in monochrome or color.
Kodak describes the performance of this CCD: "Designed for demanding imaging applications, this sensor has additional features including electronic shuttering, peak QE (quantum efficiency) of 55%, extremely low noise and low dark current. These features give this sensor exceptional sensitivity and make it ideal for machine vision, scientific, surveillance, and other computer input applications."
ELECTRONIC AND MECHANICAL SHUTTERS
This sensor has an electronic shutter allowing exposure times as short as 0.001 seconds. Most other eyepiece sized cameras rely on this type of "global" shutter alone due to the difficulty and cost of building an additional mechanical shutter into the camera body. However, in the ST-i camera we have also included a mechanical shutter enabling the camera to automatically take dark frames. This feature alone dramatically improves the performance of the ST-i, particularly when used as an autoguider. Cooling of the CCD to reduce dark current is unnecessary at the short exposure times common to planetary imaging and autoguiding, but there remains the possibility of bright pixels in an image that can raise the threshold of brightness required for the most sensitive guiding performance. The ability to automatically take and subtract a dark frame results in a very smooth background against which detection of dim stars is more reliable. Finally, while some inexpensive guiders save cost by using low cost 8 bit or 10 bit electronics, the ST-i camera uses a high quality 16-bit A/D for superior resolution of the full dynamic range of the CCD, greater than 70 dB.
|Name||SBIG - ST-i Planet Cam and Autoguider (mono)|
|Manufacturer||Santa Barbara Instrument Group (SBIG)|
|Custom Stock Status||In Stock|
Some observations –
Both are intended to fit in a 1.250 inch eyepiece opening, only the Lodestar did so, consider this to be minor and may well be fixed by SBIG as others have reported it. The sample I had did fit in a 1.253 hole.
The ST- i has industry standard connectors, while the Lodestar has an unusual connector on its guide port ST-4 interface. Some have reported problems with the Lodestar autoguide ST-4 output cable connection reliability, so decided to use my usual setup using computer USB to ST-4 converter (GPUSB, about $80 from Shoestring Astronomy).
I use the PHD Guiding program for autoguiding and Nebulosity 3 for image capture. Both of these Stark Labs programs are quite popular. This is where I had driver problems with the ST-i. The SBIG unit, being newer, isn’t yet supported by Nebulosity and needs a pre-release version of PHD (1.13.1). SBIG does include two programs on its CD that can be used for autoguiding and image capture. I’m told that Maxim DL works fine with ST-i, for both autoguide and capture.
The Lodestar driver was a normal Windows install.
The ST- i has finer resolution due its smaller pixel size but gathers fewer photons per pixel, take your choice.
ST-i camera pixel size: 7.4u x 7.4u formatted in a 648 x 486 array, 4.74mm x 3.55mm.
Lodestar camera pixel size: 8.2u x 8.4u formatted in a 752 x 580 array, 6.4mm x 4.75mm.
The ST-i has built-in shutter for taking darks, Lodestar not.
6/21/12 (Posted on 6/22/2012)