WT5L Astrophotography Equipment

This page describes the current inventory of my astrophotography hardware and software. Utilizing the equipment shown below plus several key pieces of purchased and self-generated software, I am able to acquire all images (light and calibration) with very little operator intervention. This process includes the ability to automatically suspend imaging at prescribed intervals, slew to a nearby bright star, refocus the scope (to account for focus drift due to temperature changes, filter change, etc.), then return to the object to continue imaging. In addition, when imaging at my home location, I am able to use my wireless local area network and a remote administrator software package to monitor the status and progress of the laptop imaging computer from an indoor desktop computer. When imaging from a remote location, I'm also able to monitor the status of the imaging computer from a "warm-room" laptop via a ethernet crossover CAT5 cable.

Functional Block Diagram

The following block diagram displays the details of my current imaging system. The large block titled "Scope/Camera/Mount Assembly" is, obviously, the heart of the system. This assembly consists of the Takahashi TSA-102S 4" f/8 refracting telescope (field-flattened and reduced down to f/6.04) which is rigidly mounted to a Takashashi EM-200 Temma II German equatorial mount. In turn, the imaging train is rigidly attached to the scope and consists of the SBIG ST-8300M CCD camera and the SBIG FW5-8300 filter wheel loaded with Baader LRGB and H-Alpha filters. Riding piggyback on top of the main imaging scope is an Orion short tube 80mm f/5 refractor guide scope with an attached Fishcamp Starfish uncooled CCD guide camera. Finally, a Robo-Focus stepper motor is attached to the shaft of the TSA-102's focus wheel and a dew strip heater is wrapped around the front-end of the imaging scope at the base of the retractable lens shade. Each black line in the block diagram represents a cable or connection that must be made to complete assembly of the system.

Functional Block Diagram

Astrophotography Imaging System Photos

West View of System, Scope Pointing North

East View of System, Scope Pointing North

Northwest View of System, Scope Pointing North

SBIG ST-8300M CCD Camera and RoboFocos Stepper Motor

Starfish Fishcamp Guide Camera and Orion Short Tube 80mm f/5 Guide Scope

Equatorial Mount

Arguably, the most important piece of equipment for astrophotography is the mount which carries and moves the telescope and any attached equipment such as camera, finder scope, guide scope, filter wheel, etc. Whether images are guided or unguided, the ability of the mount to smoothly and accurately track across the sky at the sidereal (star) rate is paramount.

My current mount is a Takashashi EM-200 Temma II with the Takahashi SE-L wooden tripod. This German Equatorial Mount (GEM) has tracking errors of +/- 5 to 10 arc seconds of periodic and random errors and is capable of handling loads up to 35 lbs. My setup includes three 5kg counterweights and features an integrated polar alignment scope capable of getting within 2 arcminutes of the celestial pole. A sales photo of this mount is shown below:

Takahashi EM-200 Temma II German Equatorial Mount

CCD Camera

Probably the second most important piece of equipment is the camera. My imaging camera is the ST-8300M manufactured by Santa Barbara Instrument Group (SBIG). This is a high resolution monochrome CCD camera and is based on Kodak's KAF-8300, 8.3 megapixel, full-frame CCD. The CCD array is 3326 x 2504 pixels with 5.4 micron pixels. The CCD provides anti-blooming technology to control charge bleeding from saturated pixels and microlens technology to improve the quantum efficiency of the sensor. The camera also provides single-stage thermoelectric, active fan cooling to a maximum of -40C below ambient (-35C below ambient at 80% power). The ST-8300M interfaces with the imaging computer and software via a high speed USB 2.0 interface resulting in a full-frame download time of approximately 7.5 seconds. A sales photo of this camera is shown below:

SBIG ST-8300M CCD Camera

Telescope

My main telescope is a Takahashi TSA-102S 4" refractor telescope with retractable lens shade. This scope features an 4" (102mm) aperture and a focal length of 814 mm (f/8). This scope features triplet apochromatic optics with very high color correction and knife edge baffles and over sized tube that produce very high contrast images. A photo of the Takahashi TSA-102 telescope is shown below:

Takahashi TSA-102S Refracting Telescope

Focuser

In order to achieve accurate and repeatable focusing, I use the Robo-Focus system manufactured by Technical Innovations. In conjuction with the free software, FocusMax, the important job of focusing is completely automated. As shown in the photo below, the Robo-Focus stepper motor is attached directly to the shaft of the scope's focuser. Also, as shown in the photo, I use the stock mounting plate that comes with Robo-Focus to rigidly mount the stepper motor.

Robo-Focus Stepper Motor Mounted to TSA-102 Focus Shaft

Imaging Computer

The laptop computer that I use for all my imaging is a Toshiba Satellite model A105-S1014. This computer has a 1.50 GHz Celeron M processor with 512MB of RAM. The operating system is Windows XP Home edition with service pack 2 installed. The computer features four USB ports which are all used during imaging (one port for imaging camera data, one port for guide camera data, one port for mount communications [with serial-to-USB converter], and one port for Robo-Focus controller communications [with serial-to-USB converter]). A sales photo of the A105-S1014 is shown below:

Toshiba A105-S1014 Imaging Laptop Computer

Imaging/Processing Software

The following table lists the major pieces of software that I use for astrophotography. The table is arranged by title of the software, latest version, author, phase of use (Aquis. = Image Aquisition, Proc. = Image Processing, Pres.= Image Presentation), and the purpose or use of the software.