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Author Topic: SYNGUIDER my story, but with a happy ending.  (Read 2383 times)

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Offline kaz1

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SYNGUIDER my story, but with a happy ending.
« on: 21:25:57, 18 January, 2012 »
Hi Guy's, I thought this might be helpful to the small amount of people out there that have a synguider for guiding.
Having had the synguide for several months I have only just got my head around this device, I am know expert on it but if your like me you might have struggled with this quaint little guiding unit from the beginning.
There does not seem to be many helpful guides on this device maybe because its not over popular, or  due to some very good alternatives most of which require a computer to run.
There is a very limited amount of stand alone guiders out there, and never having used any thing else but the synguider I can not comment on any of the others, only in the fact that there have been some good reviews and comments made on  other types of guiders on this great site (UKAI).
This is not a review, more of a this is what I was doing wrong write up, and hopefully the information might help someone else stop pulling there hair out.
Like most Astronomy Equipment in the UK in a normal year it does not get much use normally due to bad weather or when the weather does improve you have to get up for work the next morning so you tend not to get your equipment out to use it unless you are fortunate enough to have a permanent set up.
The latter was my problem with the synguider having pretty much a whole new set up every thing was a new experience from setting the go to mount up to imaging with a canon SLR camera.
when I got the Synguider it was only the second time I had managed to get all the Equipment out and set up to  do some  astrophotography.
My set up then was a SW 80 ed with a 90mm guide scope sitting side by side but now that I have got used to the synguider i have now dropped the size of the guide scope to 50mm and is a SW finder scope which has drastically reduced the weight of the set up, the whole guiding set up now weighs 1.6 pound or 630 grams.
Now on to the Synguider, what I was finding initially hard  was trying to get my head around the controls and as I stated earlier most of us don't get enough clear nights to practice with the setup to really familiarise yourself with the unit, so the first 2-3 sessions I was getting results not perfect but none the less results, with a small amount of star trailing, around twice to Three times  that of the star  know matter how long the picture to a certain degree, a 8 minute picture would be hardly be much worse that a 2 minute picture.
I had left the mount which is a celestron Gt goto mount in its default guide speed of 50%, so I looked into this as there was not allot of info in the Manual as to what guide speed would be best and as usual I found the answer on (UKAI) , basically if you have a long focal leghth Telescope 1500 + mm the Guide speed should be slower 25%  or like mine only being 600mm then with the focal reduce flattener it is only around 540mm, so 50 % to 75% guide speed would be more practical for that Focal  length of telescope / guide scope, Hope that makes sense.
I tried on several occasions to alter the guiding rate on the mount from between 50% to 100% with I must say not allot of improvement and all the while my shots were coming out barley acceptable.
I have attached a 5 minute untouched, apart from the cropping of the image and a resize of the  a picture of the M31 it is very blue due to the cls clip filter that is used, the blue hue  is removed during processing.
you can see the stars are elongated approximately twice that of what the stars should be.
By this time I had pretty much got my head around the controls of the synguider but was still not getting what I would class as pin point stars, and I always took my time in polar aligning the mount, if any one has been in a similar situation with other equipment, you if you are like me you tend to doubt that you have set things up correctly or there is a underlying fault with a part of your equipment, in the mean time weeks and weeks would roll by without the opportunity to get all the kit out and practice with the guiding due to yes you have guessed it the weather.
After what seemed like forever a month ago there was couple of clear nights, I spent the bet part of these two nights experimenting with the synguider trying to get it to work  as it should and it pretty much boiled down to this, I reduced the aggressiveness of the RA and Dec correction values by as much as 35-45 %  on the synguider and it all fell into place, the stars were almost 100% perfect you maybe laughing and saying is that it, well unfortunately for me yes.
Due to a lack of information on the subject of guiding with a synguider I did not know any better even though I had played with the Aggressiveness of the guiding I did not realise it would have to be that much, almost approaching 50%, and the reason for this was me thinking that when it does the calibration routine once you have locked on to a guide star I automatically assumed that it would pick the correct values ( guide Aggressiveness) for me,  and with a little tweaking it would be spot on maybe 5% - 10% which I had done I did nor realise it could be as high as 50%.

1/ Now this is what I do, after I have polar aligned the mount / balanced the telescope and equipment / ran through the mount positioning routine / found the target I want to take picture of I do this little routine with the synguider( I am assuming you are well versed on the controls of the unit)
once you have found your guide star go to the lock menu and use the manual lock which will bring up a small cross hair move the cross hair over the guide star using the arrow keys on the keypad, then press enter, it should come up with star Locked
I normally try and get the Sars brightness down to around15 to 20, if it is around say 70 I bring the exposure times down to get theses figures.
I find the manual lock quicker and more decisive then the auto routine that does not always lock on the star.

2/ I am again Assuming that you have already set the sky background interference level to your sky conditions which can be anywhere for me from 5 to 10.

3/ Now go to guiding in the main menu, here you will be presented with some options choose autocal, this will run the routine for direction and time / aggressiveness, once this is done which can take from 30 seconds to 2 minutes it will say guiding on the main screen.

4/ I then look at the values it has given me for the corrections that the autocal has given me, which for instance might be RA 500 DEC 600, I then lower these values to just a bit over half so it might look like this RA 275 DEC 350.

5/ I then do a 5 minute picture and check it on the back of the camera to make sure the guiding values are working ok if they are job done.

Also the trouble I  have found before I managed to get guiding allot better, is even after  checking the pictures on the back of my camera that has a 10x zoom on it the pictures appear to be ok with pin point stars it was only really apparent when you are looking at the full size image on your main computer screen did I realise that there was a tiny bit of trailing, Hopefully now that is a thing of the past.

I hope that this information might help someone who has a Synguider and has struggled to get good results from it like I was getting, but once you have mastered the controller and almost cut the aggressiveness in half it can guide in my opinion very well  and with out a need for a laptop, currently I have it on a SW 50mm finder it finds stars down to a magnitude of around +6 and because of the wide field of view there's always a guide star.
I  have attached some photos so that you see what I have been waffling on about
Best regards Paul.
Ps: to all the people that know what they are doing when it come to guiding with a Synguider I  hope I  haven't bored you to much.

Photos : synguider with 50mm finder attached / one photo showing a bit of trailing near the M31 and a recent photo 100% full size but cropped near the m42 with near perfect stars 5minute photo , blue due to cls clip filter(not processed).  :thumbup:

Offline astrowales

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Re: SYNGUIDER my story, but with a happy ending.
« Reply #1 on: 15:53:33, 15 May, 2012 »
good post thanks for the info!

Offline Nomis Elfactem

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Re: SYNGUIDER my story, but with a happy ending.
« Reply #2 on: 10:38:42, 16 May, 2012 »
Yeap, nice and detailed - well done and great you've got guiding running sweetly !

S.
Simon

Scopes: Astro-Tech AT-111EDT Triplet, TS65ED Quad, Orion ST80, Modded PST-90 Solar Scope, PST Cak (on loan)
Cameras: SXVF M25c, Atik 16ic, Canon EOS 600d, DMK41, DMK21, QHY 5L-II (mono & colour)
Mount: EQ6 (EQMOD), HEQ5 plus a lot (and I mean a lot) of other bits and pieces

Offline astrokumar

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Re: SYNGUIDER my story, but with a happy ending.
« Reply #3 on: 16:43:52, 02 July, 2012 »
I was wanting to read an actual review of this gyider and this is about as good as it gets. I have however decided to start with a finder-guider and a powerful guide cam and then move onto a piggy backed guide scope in good time.

 

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