Mesu flatlined

[Skipper Billy]

If this graph was a heart monitor I would not be smiling. (Or doing anything!)

As it's the guide graph from my Mesu I am grinning from ear to ear 😉 

 

 

[Dr_Ju_ju]

Grrrrr, now stop showing off !!!   you're making me jealous, & looking at the bank balance..... 

[tooth_dr]

Very nice David!  I’m still impressed with mine.

[vlaiv]

1 hour ago, Skipper Billy said:

As it's the guide graph from my Mesu I am grinning from ear to ear

I'm not buying that

Image shows that you have 0.02px error in RA and 0.01px error in DEC which translates to 0.14" and 0.13" respective errors. I really don't think you have reliable data when you are trying to measure star position to 1/50 - 1/100 of a pixel. As far as I know - centroid algorithms can determine precision down to about 1/16-1/20 of single pixel.

Your guide system is just too coarse to be able to reliably measure guide error in that range (large pixels, small guide scope).

[rl]

I don't suppose you've entered the focal length in centimetres rather than millimetres? 

(Just part of my envy management strategy...)

[newbie alert]

That means it's dead David... send it over and I dispose of it for ya😁

[Skipper Billy]

4 hours ago, vlaiv said:

Image shows that you have 0.02px error in RA and 0.01px error in DEC which translates to 0.14" and 0.13" respective errors. I really don't think you have reliable data when you are trying to measure star position to 1/50 - 1/100 of a pixel. As far as I know - centroid algorithms can determine precision down to about 1/16-1/20 of single pixel.

Your guide system is just too coarse to be able to reliably measure guide error in that range (large pixels, small guide scope).

You are probably right - I use it as a guide (pun intended) to what's happening so if it says 0.10 arc sec per pixel it is better than when it says 1.2 arc sec per pixel rather than any meaningful measurement.

[Skipper Billy]

4 hours ago, rl said:

I don't suppose you've entered the focal length in centimetres rather than millimetres? 

(Just part of my envy management strategy...)

Nope - sorry!!  (Not sorry 😉 )

[david_taurus83]

4 hours ago, vlaiv said:

I'm not buying that

Image shows that you have 0.02px error in RA and 0.01px error in DEC which translates to 0.14" and 0.13" respective errors. I really don't think you have reliable data when you are trying to measure star position to 1/50 - 1/100 of a pixel. As far as I know - centroid algorithms can determine precision down to about 1/16-1/20 of single pixel.

Your guide system is just too coarse to be able to reliably measure guide error in that range (large pixels, small guide scope).

Even so, the grouping is about 0.5 arc second, peak to peak. Can't complain at that.

[vlaiv]

1 hour ago, david_taurus83 said:

Even so, the grouping is about 0.5 arc second, peak to peak. Can't complain at that.

That is based on imprecise measurement - same as RA, DEC and total RMS. Same values used to calculate and plot graphs.

I'm sure Mesu is excellent mount and I'm sure that actual data is not far from this, but I'd rather have 0.3" total RMS that I know is correct than 0.2" total RMS that is measured without enough precision.

 

[tomato]

Wow, it may not be precise but it does look impressive. Mine is never as good as that and there are corrections aplenty, but it is carrying close on 100 kg all up. It varies quite a bit either side of the meridian but I held the record for a while on the BAT project for the tightest stars…

[tomato]

Your SNR(?) line is incredibly flat also, I never see that either.

[newbie alert]

Not that it changes the guide figures at all but you have a very precise mount that's working extremely well but you have it setup to show you over 6 mins of error? With a scale of 50

Presume you're using a lodestar?  it's big pixels that are too big to show  errors

So I'd say your mount is out performing your guide equipment..

[ollypenrice]

We can argue over the niceties of the data but it is screamingly obvious that a guide trace like this is going to take some beating. Mine are both very similar. On top of that, my Mesus are now 9 years old and they have been performing like this, every time I go out, throughout that time.  This is in commercial use and they have had no maintenance at all in that time. (And, for what it's worth, both were bought second hand, though one was here from new.) There are three other Mesus here and none of those has gone wrong either.  (The same cannot be said for 10 Micron, iOptron or Takahashi mounts based here., all of which have misbehaved on occasion.)  The only other mount from which I've experienced the same mechanical reliability is the Avalon Linear. Honoroable mention must go to my pair of EQ sixes, though, which soldier on impressively.

What is more, the Mesu, though not cheap, is probably the least expensive mount in its payload-precision class and by some margin.

Olly

[Skipper Billy]

Well we could discuss the technicalities (which are way above my tiny mind) ad nauseum but my stars are tiny, round and tight. The mount is utterly reliable and it churns out similar numbers to the above night after night with no fiddling or adjusting. 

It makes me happy which is the main thing!! 😉 

[Xsubmariner]

Fully concur with “Skipper Billy” statement, my Mesu mounts performance is similar to the above. Due to flexibility and ease of use, I replaced my perfectly working Paramount MX with a second Mesu. Now no more maintenance, grooming or T-Point remodelling after changes to the setup.

[Neil27]

I’ll add my two penneth as well.

After a few ‘operator’ error moments and learning the idiosyncrasies of the Sitech software I can get it to track and point at stuff in the sky.

Its done it twice in a row now with minimal coercion from me, I’d say that’s a success! 😊

[dan_adi]

Same experience with a Mesu 200. Total RMS between 0.15-0.3 " measured with Prism Software Guiding module. I have the pics of the guiding sessions on the Mesu 200 thread. In windy conditions I get around 0.5 " RMS, ok too, since I image at 0.93 "/pixel. 

There is a big probability I will get a second Mesu , but if it's possible with absolute encoders on it. Makes life easier.

Edited October 12, 2021 by dan_adi

[mrpizza]

I have been using my Mesu 200 MKII for several months now.  I use an ONAG for guiding on a Meade 14" LX850 at 2995mm focal length. I have been able to dial in PHD2 to consistently 0.27".  Do those of you getting better results ( I realize better in this case is being picky) utilize the Sci-Tech modeling feature?  I don't and when experimenting early on I did not see the benefit. 

 

Chris

[dan_adi]

On 20/10/2021 at 17:40, mrpizza said:

I have been using my Mesu 200 MKII for several months now.  I use an ONAG for guiding on a Meade 14" LX850 at 2995mm focal length. I have been able to dial in PHD2 to consistently 0.27".  Do those of you getting better results ( I realize better in this case is being picky) utilize the Sci-Tech modeling feature?  I don't and when experimenting early on I did not see the benefit. 

 

Chris

I did fiddle a long time ago with mount modeling, but my former Meade SCT introduced too much errors, so not an ideal scope for modeling. If not using absolute encoders, modeling doesn't do much for you.  I solved a lot of problems by upgrading to a refractor, but that's another story

[Miguel1983]

On 06/10/2021 at 14:14, Skipper Billy said:

If this graph was a heart monitor I would not be smiling. (Or doing anything!)

As it's the guide graph from my Mesu I am grinning from ear to ear 😉 

 

 

Nice ! I'm hoping to see the same on my GM2000 when it finally arrives (waiting since june).