Who just ordered an AP1600GTO...?

[Slawomir (Suavi)]

The almighty Centaurus looks very good Mike

You must be very happy now entering astrophotographers nirvana on Earth

I know I mentioned that already, but when you will get comfortable with controlling your mount with a laptop, I think APCC Pro might be a useful investment. Even with a simple pointing model that takes 20 or so minutes to build with my slow to plate solve laptop, pointing accuracy across the sky improves dramatically as targets land to within a few pixels.

[codemonkey (Lee)]

Most recent version of APCC has supposedly made some improvements and bug fixes regarding the pointing/tracking models, but I haven't upgraded yet. I'm going to try that today.

My experience to date is that it helps with pointing but I've seen variable results with tracking. I still need plate solving though because it's definitely not been dead-centering targets for me. I think it very much depends on the repeatability of errors though, and since I'm using a newt and Suavi is using a nice rigid refractor, he may have better luck there.

[gregbradley]

One of the best features of TPoint is the accurate polar alignment. Its easy to use, fast and super accurate. Its the best polar alignments I have ever achieved and once you get your camera plate solving (a bit daunting at first)
it is easy.

Also the Sky X has a slew where it uses plate solving to get the object dead centre of the camera. It does not take long either. That can save a lot of time
positioning the object.

Greg.

[codemonkey (Lee)]

I bought TSX + camera plugin not all that long ago, and got a trial of T-point. The polar advanced alignment routine was pretty awesome, telling you what adjustments to make to minimize total drift (as opposed to dec). Unfortunately with an AP mount you can't use it for tracking, only pointing within TSX so it limits its usefulness.

[strongmanmike (Michael)]

Thanks my IIS buddies appreciate all the useful feedback

While I will start to utilise more of the capabilities of this mount over time, to be honest I don't really care if I don't have perfect PA or pointing, it is really not a big issue when imaging one target over 3 nights, particularly given we rarely want the target sitting in the middle of the frame anyway for the final image, so we move the scope to frame it Once framed, I will just re-calibrate on that object, so the goto the next time goes straight to it with the exact framing ....or at least I imagine that's how it would work

Mike

[gregbradley]

Originally Posted by codemonkey

I bought TSX + camera plugin not all that long ago, and got a trial of T-point. The polar advanced alignment routine was pretty awesome, telling you what adjustments to make to minimize total drift (as opposed to dec). Unfortunately with an AP mount you can't use it for tracking, only pointing within TSX so it limits its usefulness.

Are you sure? I see a checkbox to activate tracking in T Point when TPoint is being run.

Anyway if not it does not matter as the mount doesn't need it.

Greg.

[gregbradley]

That may be fine at a certain focal length. But at 3 metres or even really 1260mm a poor polar alignment starts giving elongated stars.

At least in my setups they do.

Too bad we are so far apart as a night with my laptop there could show how it all works very quickly. Its not hard to learn really but I agree take on a bit more at a time rather than all in one hit.

Greg.

[codemonkey (Lee)]

Originally Posted by gregbradley

Are you sure? I see a checkbox to activate tracking in T Point when TPoint is being run.

Anyway if not it does not matter as the mount doesn't need it.

Greg.

I could be wrong, please correct me if I am. I believe protrack is the software which does the actual tracking correction, and according to its docs, it requires:

A Paramount MX, Paramount ME, Paramount ME II, or MKS Series Software
Bisque Telescope Control System (Bisque TCS).
2. TheSkyX Professional Edition.
3. TPoint Add On.
4. A telescope with a fixed mirror. (The random motion caused by mirror flop
can make precision tracking nearly impossible.)
5. An extensive set of TPoint modeling data (50 to 200 stars or more
recommended).

[gregbradley]

Originally Posted by codemonkey

I could be wrong, please correct me if I am. I believe protrack is the software which does the actual tracking correction, and according to its docs, it requires:

A Paramount MX, Paramount ME, Paramount ME II, or MKS Series Software
Bisque Telescope Control System (Bisque TCS).
2. TheSkyX Professional Edition.
3. TPoint Add On.
4. A telescope with a fixed mirror. (The random motion caused by mirror flop
can make precision tracking nearly impossible.)
5. An extensive set of TPoint modeling data (50 to 200 stars or more
recommended).

It definitely will activate, whether its affecting the tracking its hard to say. Its not like it makes a huge difference. I did find with the PMX that Protrack did seem to improve tracking a bit. Protrack seems a bit of a gimmick to be honest.
Tpoint modelling for PA is amazing though. For gotos as well. But I doubt those claims of being able to use Protrack only without autoguiding and getting great results. I would be happy to be wrong there.

My experience is even high end mounts require PA to be spot on or eggy stars start to annoy you. PA needs to be checked as soon as star shapes start to go off. A wet season, drought etc can perhaps shift slabs a tad. Bumping the mount walking into it in the dark etc all can throw things off.

With Tpoint though a perfect polar alignment takes me 30 minutes or less.

Greg.

[codemonkey (Lee)]

Interesting. Pretty misleading if the software appears to enable you to do it but it's doing nothing.

Agree though, TP for PA is awesome. I may well buy the TP plugin at some point just for that, but it is pretty expensive for that... given my gear is permanently mounted I'm hoping I can just not align it again until I'm forced to take it down for some reason though and thus hold onto my money for a while.

[Atmos (Colin)]

I used to use TSX extensively for T-Point models and polar alignment and I agree with Lee, ProTrack only works with SB mounts. From memory when I tried to use ProTrack it used to come up with a warning letting you know that it won't work unless a Paramount is connected. T-Point did make a big difference with pointing a few years ago when I was using an EQ6.

[gregbradley]

Originally Posted by codemonkey

I could be wrong, please correct me if I am. I believe protrack is the software which does the actual tracking correction, and according to its docs, it requires:

A Paramount MX, Paramount ME, Paramount ME II, or MKS Series Software
Bisque Telescope Control System (Bisque TCS).
2. TheSkyX Professional Edition.
3. TPoint Add On.
4. A telescope with a fixed mirror. (The random motion caused by mirror flop
can make precision tracking nearly impossible.)
5. An extensive set of TPoint modeling data (50 to 200 stars or more
recommended).

I wonder if because I am using an AP Ascom driver in Sky X that it may work.
I'd say the main thing would be to enable direct guiding which AP equivalent is pulse guide. I suspect they are the same thing. Perhaps with that setup it may work??
Next time I am using my AP1600 I'll activate Protrack tracking and see if it makes any difference.



Greg.

[Logieberra (Logan)]

I use the APV2 ASCOM driver and SkyX with my 1600. I use Tpoint for pointing but never Protrack... happy to be corrected though - bonus!

[strongmanmike (Michael)]

Originally Posted by gregbradley

My experience is even high end mounts require PA to be spot on or eggy stars start to annoy you. PA needs to be checked as soon as star shapes start to go off.

I don't get this Greg?...if you have pretty close PA (perhaps not perfect) there will be a slow drift over time of the star but the off axis autoguiding adjusts for this, as well as for any periodic error in the system throughout a sub ...so, how do you get eggy stars?

My NJP had close but not perfect PA and produced round stars just as the AP now seems to do as well

Mike

[gregbradley]

Originally Posted by strongmanmike

I don't get this Greg?...if you have pretty close PA (perhaps not perfect) there will be a slow drift over time of the star but the off axis autoguiding adjusts for this, as well as for any periodic error in the system throughout a sub ...so, how do you get eggy stars?

My NJP had close but not perfect PA and produced round stars just as the AP now seems to do as well

Mike

Perhaps the difference between 1260mm and 3 metres.

Greg.

[strongmanmike (Michael)]

Originally Posted by gregbradley

Perhaps the difference between 1260mm and 3 metres.

Greg.

Yeah I know but it is image scale not focal length that counts, so I operate at 0.83"/pix so pretty fine and as fine as many other much longer focal length systems using bigger pixels...?

I get it if your PA was a fair way off but not within 2-3 arc min..?

Mike

[gregbradley]

Originally Posted by strongmanmike

Yeah I know but it is image scale not focal length that counts, so I operate at 0.83"/pix so pretty fine and as fine as many other much longer focal length systems using bigger pixels...?

I get it if your PA was a fair way off but not within 2-3 arc min..?

Mike

Ah yes good point. I guess the PA had shifted a fair way off. The stars weren't that bad either just not good enough.

Greg.

[strongmanmike (Michael)]

Originally Posted by gregbradley

Ah yes good point. I guess the PA had shifted a fair way off. The stars weren't that bad either just not good enough.

Greg.

Assuming you have ruled out collimation and image plain tilt, I think gear backlash and guide corrections, that are too aggressive, are more likely to be the cause of eggy stars than slightly out PA..?

Mike

[gregbradley]

Originally Posted by strongmanmike

Assuming you have ruled out collimation and image plain tilt, I think gear backlash and guide corrections, that are too aggressive, are more likely to be the cause of eggy stars than slightly out PA..?

Mike

Next time its an issue I'll check that. I am using 6 second exposures and tuned the aggressiveness, usually its low as you say these are accurate mounts and too aggressive corrections just chase the seeing.

I think I have the aggressiveness around .6 with 6 second guide exposures. I have used 9 if the guide stars are dim and it does not seem to make a lot of difference to the guide errors.

Greg.

[Slawomir (Suavi)]

Just thinking out loud - I feel that when PA is out field rotation could show up more readily rather than uniformly elongated stars across the frame?

The crowd is awaiting the next image Mike