Hello, I am testing CCDAP3 with my AO8 for the fist time. Unfortunately the guide star was not very bright (about 10 mag): CCDAP, after located and drive calibrated the star, lost the star and guiding did not start. But I could do it manually in MaxIm. So why CCDAP does not perform automatically what I can do manually?
I not also that a drive calibration was performed before every exposure (as told in the manual). The AO calibration not. Why?
Thanks

Massimo

Massimo,

There's no need to recalibrate the AO. Just calibrate it once before you start your session. The results of a tip/tilt are exactly the same in any camera orientation and no matter where you are pointing. The drive settings do need to change, however so a recalibration is performed.

You might want to confirm that the drive calibration was *actually* successful. Very frequently drive calibration fails in MaximDL even though the software correctly "boxes" the star after each move. I've heard many people complain about this, but no one seems to have found a straight forward solution.

If you are calibrating your AO before you start, and the drive calibration is successful. . .and you are still losing the star, I'd bet that you have a problem(s) external to CCDAP.

-Jeff

Jeff, thanks for your reply.
My problem was not to "recalibrate" AO but "calibrate" it. CCDAP should make this with "initialize" function. So I noticed that only drive calibration was performed while AO calibration was not. Than I did AO calibration manually and have no problems, so I think I have nothing bad external CCDAP. Should I calibrate drive and AO before starting CCDAP?
And Why CCDAP does not calibrate AO?
It's strange (for me) that I can do tose operations manually and not using CCDAP.

Thanks

Massimo

The AO calibration has to be done once and once only - ever - unless you dismount the AO from the camera and reposition it relative to the imaging chip.

There is no need for CCDAP to do this since it is a relatively simple an rare setup operation.

The only thing that changes from target to target is the bump calibration. Due to the way CCDSoft does bump calibration, it is done by internal algorithm. For Maxim, bump callibration is done for each target.

Thanks John, now I think to have understood.
So if I do not touch AO8-ST10 assembly I do not need to recalibrate AO8. But if I put this assembly (AO8-ST10) on another mount/ota I will have to recalibrate only the drive. Is it right?

Massimo

Hi Massimo,

I believe if you put the ST-10/AO-8 assembly on another optical system, you will need to recalibrate everything as the FL, FR, plate scale, guider speed for corrections, etc., will probably all be different.

Frank,
I supposed what you are saying. I have an APO I often grab ang go in the field with another mount. Anyway It's not a problem to recalibrate AO8.

Thanks

Massimo