Microtouch Autofocuser

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menardre
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Microtouch Autofocuser

Unread post by menardre »

Does anyone have any background on the Starlight Microtouch autofocuser. I have a CPC100 with the Feathertouch dual speed focuser and I am planning on automating the focus with the microtouch. I know they make both a wired and wireless version. Any information relative to either the wired or wireless would be appreciated. I have my own small observatory and have a laptop connected to the CPC1100. I currently use Skytools, The SKY X, and Images Plus software.

Roger
Roger M.
Celestron CPC1100 EDGE, Stellarvue 130T refractor dual mounted on iOptron CEM120 on permanent pier mounted in Observatory. Imaging camera ZWO ASI2600 OSC, guide camera Lodestar or ZWO ASI290MM.
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Pete
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Re: Microtouch Autofocuser

Unread post by Pete »

Hi Roger,

I've no direct experience with the Starlight focusers. However, my own autofocusing experience leads me to believe that they're only marginally effective along the New England coast. Seeing is absolutely horrible until 2 hours after sunset, making best focus a guessing game beyond the capabilities of an auto-focus routine. Now, I'm always out at sunset and working at a relatively long focal length of around 2100mm, and that may or may not have something to do with my situation. But early evening seeing conditions vary from one minute to the next, and even with an autofocus routine that averages 2 or 3 frames per position, it doesn't help as a minute later you're in a nasty cell or a clear cell. Leaving the focus fixed, my star brightness or FWHM readings will vary by 30% over the period of a minute or so in the early evening.

So my personal experience is that unless you're running unattended for long periods of time manual tweaking of focus is best in unsettled conditions.

Successful imagers like Andy undoubtedly use autofocus for their all-night exposures. Maybe they've got a better take on this :?:

Pete Peterson

Visit Wishing Star Observatory at http://www.peterson-web.com/wish
Pete P.
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AndyG
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Re: Microtouch Autofocuser

Unread post by AndyG »

Hi Roger,

I have the wired version of the Micro-touch. I use it with my SV115 refractor with Feathertouch focuser. The Microtouch unit has always operated flawlessly for me; I've never had any troubles with it either mechanically or with the driver software. One thing to be aware of if you are not already is that when the motor is installed, you can no longer operate the focuser manually, you have to use the computer or push the buttons on the control unit. It takes about 2 minutes and an allen key to remove the motor to convert back to manual focus.

I never considered the wireless version since I have a USB hub at the scope and I can just attach the controller to that; I need the USB hub at the scope for all the other imaging gear, and there would be no point in eliminating the USB cable between the focus controller and the hub.

Code: Select all

Wired:
                                               at scope   -----------|
focuser
motor     ----cable----  controller -------(usb cable)------  usb hub --------(usb cable)------ PC

Wireless:

focuser
motor     ----cable----  controller                                       wireless receiver ---(usb cable)--- PC
The next big question would be what to use for auto-focusing software. I believe the Sky X camera control add-on ($199) has an auto-focus routine. I have never used it so I can't comment on it.

The ImagesPlus Camera Control add-on ($64.95 upgrade to IP) seems to also have a built-in focus routine. Again, I have not tried it so I do not know how good it is.

Another option is FocusMax (free), but that requires MaxIm DL ($399-$599).

I use Sequence Generator Pro ($99) for automated imaging, including auto-focusing. SGP focuses automatically between frames during the imaging sequence whenever the temperature changes by a certain amount. The SGP focusing routine is fabulous, and gives very good results.

I would highly recommend Sequence Generator Pro... even if you just use the focus routine and nothing else! It has a 45-day free trial.

IP and FocusMax require you to slew to an isolated bright star for focus. SGP uses the statistical average many stars in the field to determine focus, so you can stay centered on your target when focusing, rather than having to slew away and then slew back and re-center.
Andy
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menardre
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Re: Microtouch Autofocuser

Unread post by menardre »

Thanks to everyone who replied. Very good information. For the past few years I have been doing visual astronomy almost exclusively. I have been doing some wide field photography and plan on getting into astrophotography soon. My plan is to start with Hyperstar and with my Stellarvue 90T refractor. I have the Feathertouch focuser, so adding the autofocuser should not be too much of a problem. I also do have SPG so I should have the software necessary. I have a USB hub at my scope pier, so I should not need the wireless version, although I do like the idea of less cables attached to the scope, etc.

Thanks again,

Roger
Roger M.
Celestron CPC1100 EDGE, Stellarvue 130T refractor dual mounted on iOptron CEM120 on permanent pier mounted in Observatory. Imaging camera ZWO ASI2600 OSC, guide camera Lodestar or ZWO ASI290MM.
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