I am using a G-11 mount with the gemini goto system. With the mount powered up in the recommended counterweight down position (cold start) I find that the initial pointing when I slew to the first object tends to be significantly off target.

Does the plate solving capabilities mentioned in the program allow for this, or does the target need to be fairly close to correct?

How bad is "significantly off target"

rb

Roland,

Bob Benamati, a Gemini user, was one of our beta testers. Bob, can you help with Roland's question?

Roughly 5 or 6 degrees. (I'm basing this upon where the scope appears to be visually pointing, and how much I need to move the scope by hand to get the alignment star in the eyepiece fov)

Hi Roland,

Plate solving routines are generally for fine corrections and I doubt any can plate solve when the actual pointing error is that large.

Frankly, I am surprised that the error is that large. Not being familiar with the Gemini, I don't know whether or not it has a sync function. If it does, I would try syncing on a known target when centered in a high power eyepiece - be sure you are on the correct target befor syncing. Then try pointing at various parts of the sky and see how far off your pointing is.

Also, you may want to check out one of the Gemini support forums on Yahoo to see if that degree of pointing error is unusual.

Roland,

I think you'll need to be a bit closer than that....

I'm not sure why the concern. If you're cold starting, you'll need to build a pointing model first anyhow, and refine that down to a decent value on both sides of the meridian. I usually go for 4 or 5 Additional Aligns in each hemisphere.

From there, a warm restart is the way to go (if you're permanently mounted or restarting on a second night). FWIW, I can warm restart and the star will be within arc-minutes--but I'm permanently mounted.

Feel free to drop me a line if you need more info!

Good luck,
Bob

Thanks Bob,

I'm cold starting because I'm using t-point in TheSky6. Perhaps I should abandon t-point and using the built-in modeling of the Gemini instead.

I'm trying to figure out how to get the scope pointing to an object without having to remove the camera each time. I don't have enough remaining backfocus for a flip mirror. I do have the scope permanently mounted, I would like to get the setup to a point where I can automate it as much as possible. Any suggestions would be helpful.

The goal is to be able to powerup, then go inside and run everything remotely.

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AH--that's probably the issue... I wonder if the synch commands are 'synching' the mount at the same time and creating a pointing model inadvertently?? Or there might be an issue between the 'park' position in The Sky and the actual position of the scope...

FWIW--I don't use t-point at all... No need! The Gemini is darn accurate with a good model--I get <1' pointing with the FSQ/G11, and <2' with the C11 (mirror flop adds inaccuracy). T-point really doesn't add anything but unnecessary complexity!

I don't use a flip mirror either. But one thing that I've done to ensure that I don't need to pull the camera off in those rare events that the pointing is way off (say through corrupted model, or bumping the CW shaft and moving the mount), is to accurately align my finder and Telrad. Has saved me more than a few times!

Good luck!
Bob

Thanks again Bob,

Now if the weather would only cooperate I could try again.