Hello chris , please no misunderstanding here, no bashing or whatever, it is to give information about what and where.
I have found that tha sky x ascom driver permit the inibition of sync to protect t-point model
Up to SB to see if it is possible to add an other option for this ?
If not SGp can do as did Maxpilote writer and specify something diffrent if tpoint is in use, but i think it is somehow “dirty”
see :
http://www.aagware.eu/aag/tpointmapper/Help/scr/Setup/34-HowToDoWithTheSkyX_files/image012.jpg
I have posted a question in the SB forum for some clarification. If anything comes of it I will post here for those who don’t have access.
Sorry, messed up the reply to this so deleted that and am trying again. I had not planned to reply further to this thread but this is a simple reply to a simple question. The answer is yes, much closer. I currently have my solve and synch set to 5 pixels and the pixels on one of my main scopes are 1.1 arcsec so I am always less than 15 arcsec and that could be even less if I set the parameter to a smaller number. This is on a Paramount ME. It typically will take only one or two micro-slews to get to that and the time is normally less than a minute from the end of the initial “general area” slew. It is often closer than 5 arcsec, reporting 1-3 pixels at least half the time. Below is a grab from a centering process. From Park it took maybe 1.5 minutes to achieve. That would vary depending on where the object is relative to park, of course. FYI “failed” means it was greater than my set point of 5 pixels so tried again. That is typical.
Marty - I have owned and used both Paramount and 10Micron mounts. The append sync and sync features may be present in Per’s driver - but I think these are functions of the mount, not the ASCOM driver per se.
I have a portable setup with the MX. I bought the MX Polarscope and it routinely Polar Aligns within 1 arc minute without any pointing model. Compare this with the 10Micron, after half an hour I still would be grateful to be within 5 arc minutes. (The reasons for which are not in the scope of this thread). I since put permanent locators in my backyard which allow me to reproduce the mount assembly without even using the polar scope. (I do check periodically with the polar scope and a T-point but it confirms what I already know)
As CCDMan says, you do not need T-Point. It does make sense to measure and run PEC though. You need sensible polar alignment and the home position of the MX aligns to within 1 arc second. I routinely get within 1 pixel centering error on a single iteration of SGP slew and center at an imaging resolution of 1.3 “/pixel. The Paramounts guide effortlessly and any remaining PE, or tracking issues due to refraction or polar alignment issues are removed. With long guiding exposures of about 8 seconds, my RMS tracking error is less than the seeing (near London, so about 1-2 arcsecs) at about 0.4” RMS.
So in summary - if you want to make the most of a clear sky, you can dispense with T-Point and effortlessly center your target with SGP in about a minute. My entire setup time is now 15 minutes from scratch, using a bit of care and some best practices. I often assemble at twilight and then retire, let the system cool down and then switch on and run the sequence when it is dark. For that, I just power-on the system, open TSX, open PHD2, open SGP and run my sequence. I then return to my G&T and let the system take care of itself.
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Hi Buzz,
Just so you know, The MyT does not come with nor can it use a polarscope. So I am using T-point to get my polar alignment. Which is fine. I run a relatively short model just for polar alignment and then let SGP take over from there.
That’s the old TheSky driver, there’s a newer one that I wrote for SB that handles their DirectGuide guiding method. It still only has the inhibit sync option though.
It would, in theory, be possible to implement a “sync” in the driver by determining an offset between the TSX position and the SGP position and applying that to all positions and slews. That “sync” would be independent ot TSX and TPont.
I’m not going to jump in and do it for a couple of reasons:
- The SGP position and the TSX position will be different and I will
end up having continually to explain why. - I wrote this driver for SB and I think it’s up to them how this works. It’s
their driver not mine. I think we need their agreement that this is a reasonable thing to do.
Chris
all right chris that seems ok for me.
It is up to SB to see what is best for the user.
message for buzz : 30 mn spent for no better than 5’ from the pole ??, i understand that was pretty annoying
i’m always under the minute in no more than two steps on my 10 micron.
By the way , smart notice about the ascom driver functions related to mount functions.
@Martyk22 - I didn’t realise the MYT could not use a polar scope. I guess it is too small. I only used mine initially and then refined with T-Point very slightly and then don’t bother each time I assemble. If you can secure your tripod into the same location each night, you should be able to do the same.
Sorry, for reviving this thread. I bought a MyT mount and just ran into this exact issue when I wanted to center an object with SGPro.
So, it sounds my options are:
- don’t use T-Point (which would be a pity as one of the reasons to buy the
MyT was to use ProTrack) - use SGPro but don’t use “center” at all, but only slew commands
- don’t use SGPro (which would suck too - I use it now for 2 years. like it!)
And the reason is that SGPro issues a sync command after plate solving, qne
- this can’t be turned off in SGPro, or
- there isn’t an option to add the sync info to the T-Point model
Is that correct?
Obviously, I would love it if I could add sync info after a plate solve to my T-Point model!!! What are the chances to get that functionality?
Which option do other folks who use a Paramount mount use here?
MarkWhat version of the SkyX ascom driver are you using? Below is a screen shot of the version I have and the settings I use.
I run with a full T-Point model, pro-track enabled and have no issues with center function of SGP, 99% time it only makes 1 correction and gets within 3px, have the error tolerance set at 5px.
The driver can be set to inhibit sync but I find that does not work so let SGP sync back into the model.
Use a Paramount MX here.
Trevor
I’m new to the Paramount mount and T-Point. But from my understanding so far, if you let SGP sync, you don’t sync “into” the T-Point model to improve it, but basically distort it.
MarkMark,
That is how I read this thread. Sounds like if you want to use their modeling software, don’t ye auto center in SGP.
If the modeling software is correct, you shouldn’t need it anyways.
Mark:
I would suggest you don’t need to use TPoint at all. I used TheSky6 w/TPoint for years to do accurate slews for visual observing. Now that I use SGP for imaging, the slew/plate solve/center feature completely eliminates the need for TPoint. SGP will slew to the approximate coordinates of your target. This should be pretty accurate if you have done a good polar alignment and have done some kind of basic sync before you start SGP. The initial slew will only be as accurate as your mount can do (without TPoint) but SGP will then figure out where the mount is actually pointing and initiate an adjusting slew to your target. This can be repeated, if needed, to refine the slew.
Charlie
Charlie,
I agree with you. From what I could gather in the thread it’s just people wanted to use all the fancy features they’ve paid for. Centering via plate solving is as effective as anything else. My guess is they think there is an advantage to guiding via pro-track or are trying to do unguided photography. I don’t remember the last frame I lost to a guide star failing or because clouds rolled through. Between recovery mode and PHD2’s features it just works.
Either way, plenty of packages that allow them to do that. It’s just not as nicely automated as SGP.
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I am not sure what you are reading about syncing but I have it syncing into the model, from my understanding the sync command aligns the model with the current scope position, as I said I did try center here with inhibit sync into the model and SGP could not sync, just jumped around and gave up, allow it to sync back worked so I have stuck with that.
I have a 150+ t-point model and I run a 20 point rec-cal on every setup, have a perm pier but no obs yet so setup each night.
That said have to agree totally with Charlie and Mads0100 that you could happily do without a model with SGP and plate solving.
I used t-point initially to set my PA as t-point and the accurate PA feature in the SykX makes that so easy. But use it now as there, and paid for it so will use it if I can - I also believe that pro-track has improved guiding, though to be honest it is so good it is difficult to tell.
Trevor
This is still up to bisque to allows a two synch option in there driver 
one sync to add a point to t point model
one sync to offset the whole model and let sgp doing its work.
Simple but maybe bisque interest is that you keep working with the sky only…
I’m not sure why you would need that. The T-Point model will map the scope flexure and cone angle with the inaccuracies in the mount and the atmospheric refraction effects. As far as I can tell, a sync through the ASCOM driver does not add to the T-point model, thankfully, it just sets the relationship between the mapping and an absolute position?
I don’t think you would want to add T-point syncs randomly with SGP. Coming from 10 Micron, which relies heavily on model building, you need to have highly accurate clock consistency whilst doing the model and unless you are taking special precautions to re-sync the (usually poor) computer clock with a NTP, you will bake in anomalies (15" / 1-second clock error). You normally do a model in one go - so you use consistent refraction and time attributes.
Buzz,
The point of a t-point setup is to remove the need for plate solving right? In addition to all the things you listed.
I guess I don’t understand the need for syncing if you have a modeling setup like that.
This is the point (!) i understood that when using the sync to a bisque mount through sgp, that was adding a point to the tpoint model. if not (ie : it only synchronize/offset the whole model) then the aboves poster questions are pointless.
but i think what you state :
is the matter if not effective. right ?
(Edited - I got my worms muddled up)
I have a temporary setup, so does trevorn. We can both do T-Point / ProTrack models but when we mount up our gear, on to piers, we need a singular point to of reference. As we both have said, you don’t NEED T-Point with the excellent slew and center commands. We both, however, have better guiding as a result of a simple Protrack model, for if nothing else, it corrects basic drift and the guider does not have to play catch-up all the time. If the guider does not have to work so hard, then the integration times can be longer and it will not react to seeing conditions so much. So, Protract is not so useful for finding a target as smoothly tracking it. On the 10 Micron mount for instance, it will track quite well with just 20 sync points and one degree of polar misalignment. That is a bit extreme, but you see the point.