All,

I'm having two problems that are limiting my evaluation of this software significantly, and I'd like to resolve them before my time runs out and I have to make purchasing decisions!!!

Auto Exposure Settings on Guide Stars: It seems that it's only possible to manually configure guide star exposure times for each light set. There's no way that I can see to either a) use a different exposure for different objects or better yet b) let CCDAP automatically determine an appropriate guiding exposure.

Re-Calibration after Rotations: CCDAP is recalibrating the AO drive after every rotation event. My understanding is that CCDAP should be aware of the rotator and that this re-calibration should not be necessary, but it runs through the drive calibration routine every time there is a rotation event.

Lastly, I can't seem to figure out how to perform different sets of exposures for different objects. For example it would be great to set up a different series for Object A, and then another set of exposures for Object B. It looks like this is quite possible, but I'm having trouble making it happen.

I'm tracking another rotator & pointing problem in another thread, so no need to repeat that one here. . .

Any help on these three would be much appreciated. Thanks!!

-Jeff

Jeff,

There is no autoexposure for guide star setting in the current version. The guide exposure is set manually for each series and ultimately for each target. See the Light Frame topic in Help.

With Maxim, the AO bump calibration is done for each target, since Maxim uses a different bump calibration than the standard guide calibration. since CCDSoft uses the same bump calibration as its guide calibration, it is done automatically. As a practical matter, if you are using the AO, your guide exposures are perforce short, if the AO is to be effective. Therefore, the Maxim bump calibration adds minimal overhead time to the overall data acquisition time, less than a single frame download time in most cases.

First, select your targets on the Targets page. Then, on the light frames page select the appropriate target from the pulldown, set up the desired exposures and hit the Update button. Select the next target and repeat the process. When you have the exposures defined for each target, save the target list. See the Light Frames topic in Help.

John,

Thanks for the information! I didn't think about that drop down although I did see it, so that makes perfect sense.

The recalibration issue is actually a pretty significant limitation I think. The problem is that MaximDL doesn't really do the drive calibration all that well, it *very* frequently fails for no obvious reason. I saw that CCAP automatically multiplies the guide exposure by x4 for the calibration, so that means most of the time it's successful, but not always. During my last night out with CCDAP I had calibration failures 3 times in a "stress" run I put together out of 9 targets. I realize this isn't a problem with CCDAP, but based upon the plethora of other problems I've been having I've been talking to a lot of people with similar configurations to mine, and they universally agree that the AO drive calibration is flaky in MaximDL.



Any chance of automatically recalibrating the AO drive configuration via Bob Denny's approach?

http://acp.dc3.com/RotatedGuiding.pdf

I know I'm not an expert, but his overview seems solid and the settings on page 5 take into account every rotation angle one could have. Seems like it would be an easy thing to automatically take care of. . .again, understanding that I'm speaking from a position of ignorance with regards to the design of your software

-Jeff

I've been through the same analysis for a number of scenarios. I frankly don't like the way MAxim applies mount bumps and prefer CCDSoft's approach. In any case, I will put it on the list for future consideration but it won't be in version 3.

Have you considered using CCDSoft?

I have, but of course, CCDSoft has other problems. I'll try it with CCDAP tonight though. In CCDC for some reason I couldn't acquire a guide star until it was over 5000ADU. . .way brighter than necessary. I expect it would work much better in CCAP though since I can always closely estimate how much exposure time I'll need for a given guide star.

The way Maxim handles those bumps seems ridiculous to me. I get why they can get away with the lack of precision. . .but why not have one place for calibrating all mount movements? Silly if you ask me. . .

-Jeff

quote:

The way Maxim handles those bumps seems ridiculous to me. I get why they can get away with the lack of precision. . .but why not have one place for calibrating all mount movements? Silly if you ask me. . .

Which is why I consider CCDSoft superior for AO operation.

BTW, re your post on the Maxim list, it is unrealistic to expect a calibration at 1500 ADU. For reliable automated operation, you should plan on some guider headroom - at least 3000 ADU. If you start with 500 - 1000 ADU, you can guarantee some poorly guided frames due to atmospherics, high clouds, etc.

Fair enough (on the ADU count). I'll see if I can get the framing issue resolved tonight.

-J