these were the design goals for the st-402me camera: we wanted something simple and easy to use yet powerful enough to carry the "st" model prefix. the new st-402me is seen above (click to see a larger image) 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%, this camera bows its head to no other when it comes to recording faint detail in dim objects.

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, thermoelectric cooling with fan assist is provided on the standard astronomical model. an uncooled model is also planned for additional cost reduction. the uncooled model makes an excellent autoguider, tdi camera or lab camera. 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.

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@0º 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 pixels per second. on usb 1: up to 400,000 pixels per second

full frame download time: less than 1 second

standard: single stage thermoelectric, active fan, -25c from ambient typical

temperature regulation: +/-0.1ºc

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

• the st-402me is the new and improved replacement for the st-237a.
   
• this model comes with the cfw402 internal color filter wheel and rgb filters.
   
• the kaf-0402me is 75% larger than the st-237a's tc-237.
   
• it has better read noise, lower dark current, higher qe, and greater dynamic range...all for a price similar to that of the st-237a.

credit=description from anacortes telescope & wild bird

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