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JMI's Digital Focusing

What is a Digital Focuser Counter?
The Digital Focus Counter is a low cost mechanical alternative to the electronic DRO. The three-digit counter display allows 10 turns of the shaft before returning to zero. If you want focusing repeatablilty with an NGF focuser, SCT (Schmidt Cassegrain Telescope) manual focus or MOTOFOCUS, this unit will do the job. It is available for all NGF focusers, as a manual unit for use on SCT's of 5" and larger and as a piggy-back option for all MOTOFOCUS units. (The piggy-back option is available only at the time of purchase of a new MOTOFOCUS unit and is not upgrdable after purchase.)

SCT Unit with handcontroller SCT Manual model NGFC with DFC also available motorised

What is a Digital Read Out?
The electronic Digital Read Out system provides precise information on focuser position with an easy to read LED display. The display and focus control are intergrated into one hand unit. With unprecedented focusing accuracy you can return to any previous focus positon after swapping equipment or users. This is especially helpful when returning a CCD camera to focus after visual verification of the position of your telescope.
The DRO system designed for NGF focusers shows movement in millimeters with accuracy to 0.01mm. When installed on a MOTOFOCUS motor, the display units will not be in millimeters but can be used just the same for positioning the focuser. The display units and accuracy will be based on the mechanics of each focuser.

DRO installed on a MOTOFOCUS motor will be somewhat different from an installation on an NGF focuser. First, the readout is not in millimeters but it works just the same for positioning the focuser. Also, the accuracy will vary depending mostly on how much slop there is in the focuser mechanism itself.
(See image at left)

What is Smart Focus?

Smart Focus is a combination of hardware and software for precise remote control of JMI's motorized focusers through a personal computer's serial port. The system can be controlled three ways: 1) manually using the control box, 2) with the included basic focuser control software or 3) through third-party auto-focus functions found in popular CCD imaging software such as Software Bisque's CCDSoft and Cyanogen's MaxIm DL/CCD. Auto-focus software automatically brings the system into focus using the CCD camera in conjunction with Smart Focus. (JMI's focuser control software does not include an auto-focusing function.) The system includes a hand control box (AC or DC power) and PC compatible focus control software. The hand control includes a jack and cable for connecting to the focuser and a 9-pin serial RS-232 connector and cable for software control using a personal computer.

The Smart Focus system replaces the regular DRO Hand Unit (listed above) and allows one to remotely control a JMI focuser. Popular CCD software (not included) can be used to automatically focus a CCD camera.

Smart Focus includes a hand control, AC adapter, focuser/encoder cable, serial computer cable and basic focuser control software. The hand unit has two directional focusing buttons, a variable speed control, a power jack, a DB-9 serial connector and a DRO encoder jack. It can be operated using a 9-volt alkaline battery (included).

One end of the focuser/encoder cable attaches to the hand control and the other end to the encoder assembly installed on the NGF focuser or MOTOFOCUS motor (required, see above).
The serial cable connects between the hand control and the 9-pin serial port of a PC compatible computer running Windows 95/98/NT/2000/XP

JMI's standalone basic focuser control software (included on a 3.5" diskette) is sufficient to control the focuser through the PC. Automatic focusing can be accomplished through popular CCD imaging software (not included) such as Cyanogen's MaxIm DL/CCD (using SharpStar) and Software Bisque's CCDSoft (using @Focus)

The Smart Focus system includes an A/C adapter, focuser/encoder cable, serial cable and software. (Requires a motorized NGF focuser or MOTOFOCUS unit with one of the DRO encoder assemblies listed above.)