Losmandy Gemini guiding question
Posted 20 April 2009 - 01:15 AM
So I have a Laptop /USB port and a regular webcam and PHD guiding, which works great.
Now I use the regular RS 232 port of the Gemini box to connect to the computer and the webcam is USB connected with another port to the computer.
I still have some drift when I point North.
I'm using an Orion 80ED and a DFK camera on a Meade 10" and 5 minutes shows some trailing, is the Orion 80ED f/7.5 not good for guiding ?
Or do I need to use the specific guiding port on the Gemini ? I thought this was only for specific CCD use ?
Posted 20 April 2009 - 03:16 AM
Posted 20 April 2009 - 04:29 AM
What cable do you use for that, I mean the connector that goes into the guiderport of the Gemini box ? Is it the same as the RS232 ? I guess not.
Posted 20 April 2009 - 08:17 AM
Here is why I ask... you'll need an adapter from USB to the "ST-4 compatible" guiding interface on the Gemini controller. I'd recommend having a look at the Shoestring Astronomy web page for the pieces you need. If you are using the NEW style Gemini box (the NEW style has a circular DIN connector to connect to the motors), then you will need the part "GPUSB". If you are using the OLD style Gemini box (the OLD style has a modular RJ-45 connector to connect to the motors), then you will need the part "GPUSB-AH". He also sells the flat guide port cables in 7 to 25 foot lengths. There are also coiled guide port cables that he sells but do yourself a favor and avoid them - IMO they always put strain on the connections and always seem too short because they are continually trying to coil up.
Posted 20 April 2009 - 09:39 AM
As already asked, which version of Gemini do you have? Your Orion 80 should be fine. I've also used a TMB 80/480 successfully.
Posted 20 April 2009 - 02:18 PM
So what is your suggestion to guide thru a laptop ?
With a camera attached also thru the laptop ? and PHD guiding.
Posted 20 April 2009 - 02:37 PM
SSAG to the Autoguide port.
SSAG USB cable from the laptop to the SSAG.
That's it! The SSAG gets it power from the USB cable so that's the extent of the connections.
In case you don't know the drill to connect, first, goto the menu tab at the top and select "On Mount"
Then click on the camera icon in the lower left and select Starshoot. You're supposted to then click the telescope icon to ensure that the mount and guider are connected, but with my Gemini, it automatically connects the two.
I then select a 2 second exposure loop, find a star, stop the exposure loop, click on the PHD icon and watch it do its thing. I hope this helps!
Posted 20 April 2009 - 02:56 PM
Maybe my Gemini was not programmes in Photographic mode.
I re-set it in All speeds and try again tonight, if the weather cooperates.
PHD guiding connects fine over the RS232 port, but I was concerned that the mount did not follow the software because of some star trailing after 3 minutes.
The mount is really good aligned in the E and S, I actually never checked it out in the North, I used to use my Meade 14" forksetup for that part.
Thanks guys for the help.
Posted 20 April 2009 - 05:06 PM
also you might consider taping over the ports and vdc out that you are not using to keep moisture out of the unit.
Posted 20 April 2009 - 06:05 PM
I did tape it all, but took it off for the picture.
Posted 20 April 2009 - 07:24 PM
If so then I will buythat cable.