To be honest, with the AO sitting in a box I wouldn't worry too much about this issue, as when that is hooked up you are going to be aiming to guide with exposures much smaller than 0.5s. If you had the same issue with the AO connected then I might go chasing things. Chances are you arent going to find a problem, and if it is not an issue with AO working, then dont fix a problem that isnt there.
PME or PMX I would be going for a flat line.... That's what you pay for.
I installed the AOX and had to add another counter weight. That makes 5 on my PMX.
I did a slight balance adjustment and now can guide easily with 1 second guide exposures.
Using the AOX also has proven to be quite good too. Tonight I guided 3 subs in Ha. 900, 1200 and 1800 seconds. Stars looked round in all three subs. Some wind about tonight and seeing was average.
I found a quite bright guide star and was guiding at 0.5 seconds or 1.1 hz. Further testing will be needed to settle on settings and integration into remote automation. Attached is a 100% crop in the centre of the image with the AOX.
I'm hesitant to point this out since you're having success and generally speaking it's best not to fix what isn't broken, but the star profile there looks a bit squared off at the top, which suggests to me that your longer exposure actually clipped that star which would have some impact on centroid calculations and thus guiding... not exactly sure how that would manifest in terms of corrections and/or reported RMS, but someone else more knowledgable than I am should be able to chime in there...
Looking very good Paul. To be picky though those stars are still a bit elongated. I don't think that shows up in the final image though.
1x1 binning shows up even slight errors.
I'm hesitant to point this out since you're having success and generally speaking it's best not to fix what isn't broken, but the star profile there looks a bit squared off at the top, which suggests to me that your longer exposure actually clipped that star which would have some impact on centroid calculations and thus guiding... not exactly sure how that would manifest in terms of corrections and/or reported RMS, but someone else more knowledgable than I am should be able to chime in there...
Cheers,
Lee
That's an interesting observation Lee. This is just MaximDL picking the guide star only. So it must be picking the star that is can guide on or the brightest star. I too wonder if that would have a significant effect on guiding. I suspect not give the diameter of the star, but perhaps it does.
Quote:
Originally Posted by gregbradley
Looking very good Paul. To be picky though those stars are still a bit elongated. I don't think that shows up in the final image though.
1x1 binning shows up even slight errors.
Greg.
That image of Carina is a few days old Greg. That is while I was playing with the AOX. The guide graph is all I was demonstrating in my latest post.
The image taken with the AOX does have slightly elongated stars. It seems to be caused by the AOX reacquiring the star and then no delay being applied to the exposure despite asking for one in the options menu. I am planning on asking Cyanogen why this is being caused. I have delay at 10 seconds but when I do that the AOX part of the software freezes. Weird stuff.
I'm glad things are working out with changed guiding. But, I'm guessing there might still be an underlying mechanical issue that you are just guiding out. Today this popped up on the SB Forum (When I saw the title I thought it must be you!, But, no)
Pretty sure people sync in an attempt to improve pointing. It does, but only in a small area near the sync. My understanding is that it will double the error following a meridian flip.
I'm thinking of asking the question on the SB forum. What if one syncs to improve local pointing, but, after finishing in that area of the sky the sync is deleted? Does the T-Point model just return to the previous condition prior to the sync, or, is it permanently corrupted? I can think of situations where pointing might be a little off and you just want a very quick fix. It would be easier and much faster than a full recalibration if deleting the sync brought one back to the earlier state.
Yeah I've done that when the model goes off for some reason and go-tos are not even close. A sync will make it work again. Its just finding that initial object that can be hard. I usually go for a really bright star and follow the out of field star flares to locate the star or something like M42 that is large.
The AOX can hide mount errors, so unless you perhaps have a bad pec recording, it's best you consider changing to an AP mount. That would fix all possible problems.
