New Mesu 200 - imaging isn't supposed to be this easy!

[MartinB]

For several years I've been very happy with my EM200 but, in the quest for gathering as much data as possible in a limited time, I have decided to try running 2 imaging scopes at the same time with one using an off axis guider. The EM200 doesn't really have the heft for this so enter the Mesu 200.

First of all a big thank you to Steve Richards for the beautifully lucid quick start guide. Also to ncjunk for sharing his learning progress. Extremely helpful.

Took a week end break with my wife in Norfolk and on Sunday drove over to Kelling to pick up the mount from Bernard (Modern Astronomy). Nice run through from Bern

Home Sunday evening, surprised at how easy it was to get the mount on the pier. Thought I might need to enroll my neigbour's help but it was a straight forward one man job. With Steve's guide in hand it was an easy job to get the mount set up mechanically along with FSQ106 and guide scope (keeping it simple to start with!). The friction plates feel a bit weird at first but it was a straight forward job to balance the scopes.

Monday - loaded up the software carefully in the order suggested. Needed to run the CDM20830_SETUP file for the usb to serial conversion before the computer was able to recognise the Sitech software (all covered in Steve's guide). Loaded up Sky6 and added necessary properties and Sitech instantly recognised and connected. Checked the info using Sky6 and switched off nutate, aberrate and refraction. I'm guessing Steve has these checked for Carte de Ciel but they should be off for Sky6 (all to do with corrections to J2000 and making sure you don't have two sets of software doing it). It was cloudy so that was it for the evening

Tuesday - Clear sky!!! First observing session. Sorted out my inits. Offset init to tell sitech where it's pointing and then calinits to build up a model of the sky. Easy, especially after having a quick look through this thread http://stargazerslounge.com/topic/191549-mesu-200-with-sitech-ii-controller/?hl=%2Bmesu+%2B200Had some happy slewing and then parked the mount. Then unparked the mount and did one iteration of polar align (the article on how to do this in the Sitech operation manual is spectacular in it's capacity to befuddle!). Couldn't contain myself any more - Slewed to M31, spot on. Slewed a little to find a decent calibration star. Calibrated the guiding - star finished exactly where it had started. Slewed back into position. Needed a 5 second exposure with the guide camera to have decent 10000 ADU guide start to work on. Started tracking. Sub arc second guiding. In fact I think the guide graph was really a track of the seeing variations! 3 minute sub - perfect. Slewed to The Heart Neb with the intention of running a 30min sub but clouds stopped play.

Wednesday - Mapped the horizon ready for automated plate solving calpoint mapping (I hope it's easier to do than to say).

Today - gen up on the plate solving and mapping routine. It's not necessary really to do this mapping excercise since a simple offset init with a couple of calinits will do but it sounds fun.

Next clear night - a couple more polar alignment iterations followed by automated sky mapping. Then....IMAGE!!!!

So - no "device not recongised", "guide star failed to move 5 pixels", "unable to connect", "incorrect parameters", "runtime error" etc etc etc. This isn't imaging as I know it!

[michael.h.f.wilkinson]

Sounds like you got yourself a winner. If ever I get an observatory of my own, and I fully enter into the Dark Side, I will certainly have a good look at the Mesu

[Peter Drew]

Sounds far from easy to me!   

[Astroscot2]

Congrats on the new mount Martin, sounds like the install is all going to plan.

Clear skies

Mark

[MartinB]

Sounds far from easy to me!   

It's the non intuitive terms software developers like to use that makes everything seem much harder than it needs to Peter.  It really is as straight forward as setting up my CGEM via a handset but instead of offset init the CGEM equivalent is called "align".  After a 2 star align with the CGEM you can refine things using further stars for "calibration" which Sitech calls "cal inits".  

[Horwig]

Don't have the MESU, but I do use the Sitech on my mount, I use it with Stellarium and Stellarium Scope via the Sitech Ascom driver.

I'm very lazy, I point at a star, sync in stellarium, slew to a star somewhere near my target and check centering (which is usually bang on), slew to target, fire up SGP and PHD, and image away, never fails.

Oh yes, that is at 1500mm fl

H

[MartinB]

Don't have the MESU, but I do use the Sitech on my mount, I use it with Stellarium and Stellarium Scope via the Sitech Ascom driver.

I'm very lazy, I point at a star, sync in stellarium, slew to a star somewhere near my target and check centering (which is usually bang on), slew to target, fire up SGP and PHD, and image away, never fails.

Oh yes, that is at 1500mm fl

H

That doesn't sound lazy, it sounds efficient! Exactly what I'm used to doing with my EM200. With the Mesu and Sitech I expect to be doing the same apart from not having to do the syncing every time.

[Astroscot2]

Hello Martin, Dont you have to do a offset init on start up each time ?

Mark

[Zakalwe]

Great write up Martin!

I now am beginning to appreciate what Olly means when he says that the Mesu mount practically disappears into the background.

Hello Martin, Dont you have to do a offset init on start up each time ?

Mark

Yes- the Offset Init gets the mount tracking. When you Unpark the mount, it doesn't kick the tracking off. The first init does this.

[Owmuchonomy]

Didn't understand much of that but I enjoyed reading it and it's obvious you are extremely happy with the result. Great stuff. One day maybe.

[MartinB]

Don't worry if you don't understand much of it Chris. So far I've just followed instructions a bit like painting by numbers.

I thought that if the scope was properly parked it started tracking on unpark. Here's what the operations manual says,

"If the mount has not been physically moved since

it was parked, (everything can be powered down while parked and then later powered back up),

then the initialization data that was valid when parked is still valid. The mount will know where

it is, and is totally ready to do a GOTO and be accurately tracking."

It also talks about it enabling observations of Venus during daylight!

Am I missing something?

[Owmuchonomy]

Venus in daylight... Just check out my website below. :-)

[ollypenrice]

I'm glad you're glad, Martin. I've sung the praises of this mount, as is well known, but only because it just works for me. It's doing it again tonight, as I type. When, eventually, I drop a sub to guide error I promise I'll post - but it has never happened so far. 

Olly

[MartinB]

Like that conjunction pic Chris.

I have high expectations Olly.  The EM200 only lost me a sub once, probably because of a backlasth problem in dec.  Now I routinely only correct dec in one direction and everything is fine.   That is one job I won't have to do with the Mesu!

[ollypenrice]

Like that conjunction pic Chris.

I have high expectations Olly.  The EM200 only lost me a sub once, probably because of a backlasth problem in dec.  Now I routinely only correct dec in one direction and everything is fine.   That is one job I won't have to do with the Mesu!

This is how both Tom's and my EM200s like to run as well. Only correct one way in Dec.

Olly

[bilgebay]

Congrats! Your experience is similar to mine So easy indeed. 

I only do a single star alignment and continue to PHD and SGP to start the imaging... no need for a sky model at all.. I built a sky model a few times but I have yet to see an added benefit of it.

[Owmuchonomy]

Like that conjunction pic Chris.

Thanks very much.  Crude but effective? It was warm enough that evening to sample the St Emilion concurrently.

This is how both Tom's and my EM200s like to run as well. Only correct one way in Dec.

Olly

.... is there any other 'way'.  Dec just wanders too much otherwise so I either switch off guiding in Dec or go unidirectional.

[MartinB]

You can offset the balance sufficient for gravity to take up the backlash or you can use backlash compensation.

[Zakalwe]

Don't worry if you don't understand much of it Chris. So far I've just followed instructions a bit like painting by numbers.

I thought that if the scope was properly parked it started tracking on unpark. Here's what the operations manual says,

"If the mount has not been physically moved since

it was parked, (everything can be powered down while parked and then later powered back up),

then the initialization data that was valid when parked is still valid. The mount will know where

it is, and is totally ready to do a GOTO and be accurately tracking."

It also talks about it enabling observations of Venus during daylight!

Am I missing something?

AFAIK, it will track on Unpark if “Track on Start” was checked in the Mount Parms tab of the SiTech Config screen, otherwise it will wait for an offset init.

If Track on Start is ticked, then the Unpark command will be disabled.

[MartinB]

Thanks Zak, I'll investigate, hopefully some clear nights coming at the end of the week

[gnomus]

Are there any specific settings you Mesu fellows use in PHD2?

[Zakalwe]

No...I've carried my EQ8 settings over. However it takes a bit longer to calibrate than I like, do they need tweaking. I won't do that till I understand the SiTech better amd until I build a proper mount model. That will smooth out the already impressive tracking.

[MartinB]

I'm using Maxim so no idea about PHD.

[gnomus]

OK. I only ask because I have just done something rather foolhardy......

[Zakalwe]

OK. I only ask because I have just done something rather foolhardy......

Pray tell....

:grin: :grin:

How is Bernard these days? :laugh: :laugh: