SBIG ST-402ME Monochrome CCD Camera
These were the design goals for the SBIG ST-402ME camera: We wanted something simple and easy to use yet powerful enough to carry the "ST" model prefix. The new SBIG ST402ME camera is equipped with the optional T-thread to C-mount adapter ring and lens. For use at the telescope, a 1.25" nosepiece screws into the T-threads of the front plate.
The small size and light weight makes this camera very easy to handle and set up. A custom internal filter wheel and shutter lets you take dark frames and tri-color images automatically. Best of all, the low noise and extraordinary QE of the KAF-0402ME CCD makes this one of the most sensitive CCD cameras available to amateurs at any price. Simply put, there is nothing that can touch it in its class, except of course the dual sensor, self-guiding ST-7XME camera. The same technology that is used to achieve such high quantum efficiency in the KAF-3200ME CCD is also used with the same effectiveness in the KAF-0402ME CCD. With a peak QE of nearly 85%, the ST402ME camera bows its head to no other when it comes to recording faint detail in dim objects.
Enhanced Cooling Included!
An enhanced cooling package is now standard equipment on the SBIG ST-402ME, ST-1603ME and ST-3200ME cameras, which improves the cooling delta by approximately 10 degrees C. The upgrade consists of (a) a larger heat sink installed in the camera, (b) a larger 50mm magnetic levitating fan and fan guard, (c) a new back plate with openings to accommodate the extension of the fan housing and guard, and (d) a board inside the camera that routes additional power to the TE cooler. No additional external power is required. The addition of the new parts increases the depth of the camera body by 4mm and the fan plus fan guard adds another 10mm. The backfocus is not changed.
The topmost graph in the image above shows the improvement in cooling performance as a function of delta from ambient temperature after installation of the enhanced cooling package compared to the standard camera. In SBIG's first production prototype camera, the maximum delta achieved was -35 degrees C below ambient at 100% power. After allowing the camera to stabilize, it was able to regulate the temperature at a delta of -31 degrees C from ambient with less than 95% power in a warm room (approx. 24C). They feel comfortable specifying typical performance of approximately 30 degrees C below ambient, regulated to +/- 0.1 degree C (user's set point). The bottom graph shows the typical dark current as a function of the absolute temperature of the CCD.
Similarities to the ST-237A...
Like the ST-237A, this single sensor camera is designed for light weight, low cost and high performance. The camera uses a monochrome CCD with an internal filter wheel and custom filters enabling it to do both high sensitivity B&W imaging and RGB/LRGB color imaging with the same camera. The CCD is centered in the camera body and is correctly spaced for Celestron telescopes having Fastar or Hyperstar optics. The camera body is all metal construction (black hard anodized aluminum).
Single stage, regulated, enhanced cooling is provided on this model. At 4 x 5 inches, the camera head is somewhat wider than the ST-237A, but it is only 1.8 inches deep with electrical connections on the side. This gives the camera the shortest possible protrusion from the rear of the telescope to allow maximum clearance when imaging objects in the north with a fork mounted telescope.
This size and shape also makes it possible to put the filter wheel (optional) inside the camera, even though the KAF-0402ME CCD requires larger filters than the ST-237A. Electronic relays provide typical autoguider output from the RJ-11 jack, so the camera can be used as a highly sensitive autoguider with a larger field of view than most other autoguiders. While somewhat wider than the ST-237A, this new camera is still fine for all Fastar equipped telescopes. The additional width will not affect its use as a Fastar camera in the slightest.
Differences from the ST-237A...
The KAF-0402ME Imaging CCD is about 75% larger than the TC-237. It also has slightly better read noise, much lower dark current, significantly greater dynamic range and higher QE than the TC-237. All of these factors combine to make a more sensitive detector with greater field of view. The KAF-0402E/ME CCD is available only in NABG. For fast systems such as the Faster, the KAF-0401LE (ABG) version is also available as an option.
All new electronics are contained entirely in the camera head. There is no separate CPU box. The computer interface is USB 2.0 (USB 1.1 compatible). The high speed transfer rate is approximately 800,000 pixels per second. With some overhead, a full frame, high resolution image will download in approximately 0.8 seconds using USB2.
A regulated power supply is built into the camera so you can operate directly from a 12V battery or other unregulated 12VDC source. A wall transformer is also supplied for operation in North America from 110VAC.
- CCD: Kodak KAF-0402ME
- Pixel Array: 765 X 510 pixels, 6.9 X 4.6mm
- Total Pixels: 390,000
- Pixel Size: 9 X 9 microns
- Full Well Capacity (NABG): ~100,000 e-
- Dark Current: 1e/pixel/sec@0??? C
- Antiblooming: Option (KAF-0401LE)
- Shutter: Electromechanical
- Exposure: 0.04 to 3600 seconds, 10ms resolution
- Correlated Double Sampling: Yes
- A/D Converter: 16 bits
- A/D Gain: 2.3e-
- Read Noise: 15e RMS
- Binning Modes: 1 x 1, 2 x 2, 3 x 3
- Full Frame Download Rate: On USB 2: Up to 800,000 pixels per second. On USB 1: Up to 400,000 pixels per second
- Full Frame Download time: less than 1 second
Optical Specifications (8" f/10)
- Field of View: 12 X 8 arcminutes
- Pixel Size: .9 x .9 arcseconds
- Limiting Magnitude: Magnitude 14 in 1 second (for 3 arcsec FWHM stars, magnitude 18 in 1 minute)
- Cooling - Standard: Single Stage Thermoelectric, Active Fan, -25C from Ambient Typical
- Temperature Regulation: +/-0.1???C
- Power: 12VDC, Power Supply included
- Computer Interface: USB 2.0 (USB 1.1 compatible)
- Computer Compatibility: Windows 98/200/Me/XP
- Optical Head: 4 X 5 X 1.8 inches
- CPU: All electronics integrated into optical head; no CPU
- Mounting: T-Thread, 1.25" nosepieces included
- Weight: TBD
- Backfocus: 0.69 inches
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