Accurate focusing requires that the eyepiece or imaging device be set to a precision of a few thousandths of an inch. It is almost impossible to do this by hand because of the inability to make such small changes, and the inability to make the same change in reverse due to inherent backlash in most optical systems. To accomplish this, only a digital focuser will do.
RoboFocus will fit nearly all scopes. In some popular scopes (e.g. LX200) we provide custom brackets and hardware. With Rack and Pinion focusers, we will provide the custom size coupler to attach the motor to the focus shaft. Once the motor is connected to the shaft, the next step is to install brackets to support the motor. To allow the user to fit almost any application, we provide a pair of simple brackets that can be easily bent to fit.
Yes. RoboFocus brackets and mounts are held onto the scope with existing screws or a high quality double-sided VHB (Very High Bond) tape that can be removed if needed at a later time. If transferring to a new scope, we will work with you to provide proper adapter parts. If you wish to use RoboFocus on more than one scope, we recommend installing a separate stepper motor on each scope and transferring the control unit as needed.
Yes. You can base it upon the control program we supply (it is open source), or write your own program to take advantage of the various RoboFocus commands that are a part of our documentation. The control program is also ASCOM compatible for those writing their own control routines.
Yes. Although many scope focus easily and accurately when you have the instant feedback of the visual object, others (such as SCTs), are difficult to focus due to their high backlash. In many cases, you will find that the hands-off focusing, (not having to touch the scope), reduces vibration and makes focusing quicker.
Yes. It compliments the remote operating capability of DDW. RoboFocus and its control program can also be used in parallel with all scope programs. If you use the optional Remote Power Module through RoboFocus in addition to the remote power control you have with DDW, you will have a total of eight independently controlled outlets.
Yes. The RoboFocus control program works seamlessly with the focus routines in packages such as CCDSoft and MaxImDl to provide totally automatically focusing.
The quickest way to focus is to image using a medium bright star. Most CCD software supports a convenient focus mode providing peak brightness and/or image size measurements. A quick succession of images will converge quickly on perfect focus. Using RoboFocus, you can focus directly on the moon or planets; however, it is faster to use a nearby star.
Yes, particularly because of the ability to make small focus movements and to return to the best focus found.
The best way is to refocus regularly if you think the focus might be changing, (RoboFocus makes that a quick process). Mirror flop appears to be less severe with RoboFocus because the mirror is always moved in the same direction.
The RoboFocus stepping motor and typical bracket weigh about 15 ounces.
If you run the RoboFocus from a PC, yes you will need a serial port. If you are lacking an open port, we offer a "pass-through" (LX200, Gemini and AP command sets), which allows sharing of one port, and a single USB to serial adapter.
The physical set-up is that you connect a cable (provided) from your PC to the RoboFocus controller and another cable (also provided) between RoboFocus and the scope. Both the scope and RoboFocus software will be running on your PC. Each program will have a menu item for opening/closing the COM port, so you switch between programs by controlling which is open on the port.
The latest version of RoboFocus, (RF3), includes temperature compensation as a standard feature. Some scopes change focus as the temperature changes. Thus, you will benefit from a technique for measuring temperature and automatically making the appropriate focus changes. The sensor is inside the controller (external probe no longer available), and the RF control program includes a module for creating a dataset to record how your scope's focus responds to temperature changees. You can then set RoboFocus to adjust the focus automatically.
We evaluated the quality of focusing an LX200 using RoboFocus on the scope's focus knob and on a separate JMI NGF-S Crayford style focuser. The results showed that RoboFocus on the focus knob performed as well as on the NGF-S. This paper can be downloaded on the Products page.