Alain Maury

Hello, Answering an old post. I have several people in my telescope farm here (in northern Chile) who have ASA mounts. And they have had similar problems. Try to download the trial version of prism (https://hyperion-astronomy.com/ ), everything is integrated, and things are normally a lot smoother. First take an image, download to nova. astrometry.net, this will give you the focal length and orientation of the image, which you put in the settings if you didn't knew it before. Then the local astrometric engine works a lot better than with pinpoint. Just try it. With my DDM60, I start autoslew, make a home find, start prism, take an image, ask to recognize the field, I am always very close to the position, and I am ready for the night. There is a lot of interest of having something integrated, instead of a suite of various software which were not designed to work together in the first place. Autoslew is ascom compatible, so is prism, and they work very well together, much better than with maxim, pinpoint, focusmax, and what not...

I am using prism since version 4 (it's version 10). So it's been more than 20 years. And it works quite well with DDM85 and 60. I am on the contrary slowly discovering the ASA software since I have a few in my own observatory and I recently acquired a (used) DDM60 on which I have a RASA scope. Did I understand correctly that MLPT is a way of "preparing" a long exposure ? Something like taking frames on the positions where the mount is going to be and then according the astrometry result, the mount is going to follow that path on the real exposure ? Isn't this redundant with the pointing model. I mean if there is a pointing model, deriving it to get a tracking model is feasible, and when the mount tracks in the sky it should not have a constant speed, but should follow the tracking model (i.e. the derivative of the pointing model). With the script language of prism (which is very simple to program) one can do almost anything. Now, giving speeds to the mount in order to follow a given track could be possible, even though I am not sure ascom does allow to tell the mount to go to very very slow speed like the ones needed in declination to follow the mount's flexure and change in refraction. Instead of changing the speed, one could also change the reference position (shift the mount by one arc second when it's necessary). From what I have seen though the mount can track very well for quite long individual exposures, so don't understand why MLPT would be needed since after the exposures it's quite easy to recenter all the images... If somebody can give me more informations, I can see to make a script to do that. Right now I am working on a script to generate .pox files directly from prism, in order not to have to purchase maxim and pinpoint. Just need a few more informations from ASA. Alain