Guidescope tips needed! Anyone used a startravel 80?

[Mr Bergman]

Hi all, 

I have a NEQ6 pro with a Skywatcher 190MN, and I want to start autoguiding! 

I have made my mind up for a Skywatcher standalone synguide, and I am now looking for a suitable guidescope. I heard that the guidescope should be about 1/2 to 2/3 of the big scope´s focal length, and also fairly fast to easier find good guidestars. So, why not use a cheapo Startravel 80mm, 400m f5 for about 100euros? Or should I choose something else? 

Best regards, 

Erik

[Mr Bergman]

OR I have an option for this one; http://www.astrosweden.se/80mm-guideteleskop-paket/19795-0     

Little longer focal l @ 600mm instead. 

[ollypenrice]

I use the ST80 on two rigs. It's fine. I wouldn't use a standalone guider myself, though.

Have you thought of an OAG? Your scope is a big boy and any help you can give the mount might be appreciated! Also any refelector is ideally guided by OAG because of the possibility of mirror movement. This is what we use on Yves' big reflector.

Olly

[JamesF]

The ST80 is very widely used as a guidescope.  I'm sure you'd find plenty of advice and help should you need it if you do decide to use one.

James

[Mr Bergman]

Thank you Olly and James! Nice to hear others use this as a guidescope.  I would like to use an OAG and my laptop later on, but I need to be able to move around without my computer now. And because I am a novice the standalone system feels easier to begin with. ( I guess I am wrong though:-)) 

Oh, by the way, I was talking to you earlier Olly about buying a ED80, but I got such a good price on this setup secondhand, that I went for it directly. I know it will be a steep learning curve, but I´m on it! The focal length makes it unforgiving imaging unguided...

Erik

[Freddie]

I used a ST80 on my MN190/NEQ6 and it was ok but difficult to remove all flex and was pretty heavy. I moved to OAG and it is SO MUCH better. Not sure the stand alone would be any easier but not wanting the laptop is obviously an issue, though that would obviously also help with your main image capture potentially.

[Mr Bergman]

Thx Freddie, yes it´s nice to be able to leave the laptop at home, especially when it´s very cold during winter. I´ll have to let all this sink in and think about it a little. Until then I might just try to improve my unguided subs...

[ollypenrice]

Beware of things which seem easy in this game. Complexity, to quote a designer friend, brings control.

Olly

[Mr Bergman]

Beware of things which seem easy in this game. Complexity, to quote a designer friend, brings control.

Olly

 Then I bought the right equipment at least!

[opticalpath]

+1 for OAG (I use one with my MN190).

But accepting that you will start with a separate guide scope .....

1/2 imaging focal length should be plenty. Auto-guide programs work on a calculated centroid of the guide star, i.e. to a fraction of a pixel, so no need to go longer.

Differential flexure is the main bugbear. Guide scope and camera have to be very solidly mounted so they remain locked in position with respect to the imaging optics as the scope moves around the sky in different orientations. The guide scope mounting rings, focuser and camera cables are potential weak spots; any tiny movement of the guide scope or camera will result in imperfect guiding, so try to get guide scope and camera well locked down. Use threaded extensions on the guidescope focuser drawtube rather than racking it out, for example. An ideal guide scope would have no focuser, just a solid connection from objective to camera. And if short enough focal length (say 200-300mm) with a wide field, might even be solidly bolted to the imaging scope with no adjustable rings.

But even after you've done all that, as Olly said, you can still get some movement of the imaging scope mirror to upset things. Several MN190 owners have found mirror cell movement to be a problem affecting collimation and have added shims to prevent this. (See this thread: http://stargazerslounge.com/topic/141012-skywatcher-190mn-fitting-of-a-moonlite-focuser/)

Adrian

[PhotoGav]

Just a nudge to encourage you not to be put off by the laptop route...

I was wondering what to do; standalone or laptop guiding. I listened to advice given on SGL and went for a QHY5-II through the 9x50 finder on my ED80 on an HEQ5-pro with a laptop running PHD. I've used the set-up a couple of times and it is brilliant. It was really quite easy to get it all working and my subs are pin sharp, max duration attempted so far is 20 minutes.

Once using a laptop, I decided that I may as well go the whole hog and have EQMod, BackyardEOS & Alignmaster running too, which make everything way easier. The final (well for now anyway) piece is Cartes Du Ciel, which I set up yesterday evening and now have almost full control of the set-up from Garden Mission Control (a picnic table & deck chair).

The biggest advantage is the deck chair... Once the image run starts I can just recline and enjoy the night sky, clouds permitting!

Go for it, a laptop really is a winner. Also, my set-up is ready to easily swap out the dslr for a CCD when funds allow...

[IanL]

This isn't totally applicable if you are planning to use an autoguider, but the first part may be of some help in deciding about the pros and cons of OAGs vs guidescopes, the perils flexure and making sure you have an appropriate image scale for the guider vs. the imager:

http://stargazerslounge.com/topic/188777-phd-guiding-basic-use-and-troubleshooting/

Personally I wouldn't want to start out learning how to guide on a long focal length scope (I did, it didn't work very well, got an 80ED in the end, and it does).  You may have less issues with a MN than I did with an SCT in terms of mirror movement, but it is still going to be hard work at first.  That's not meant to put you off, but everything in this game is hard won which makes it more worthwhile when you get a good result.

[IanL]

Once using a laptop, I decided that I may as well go the whole hog and have EQMod, BackyardEOS & Alignmaster running too, which make everything way easier. The final (well for now anyway) piece is Cartes Du Ciel, which I set up yesterday evening and now have almost full control of the set-up from Garden Mission Control (a picnic table & deck chair).

Now you just need Astrotortilla and you really will have mission control sorted out - why faff about looking for your target when the computer can find it for you? (Oh and a second computer or tablet/smartphone with Teamviewer, a sofa, a big screen TV, a pipe and some slippers; then you can sell the picnic table and deck chair!)

[LouisJB]

I use the ST80 / QHY5L-II / laptop (mac) with PHD and can't really fault it, the camera / guider has worked brilliantly. Just remember to calibrate after slewing to a new target. Always found stars to guide on, I've seen M81/M82 in PHD while guiding so the camera/tube is definitely quite sensitive. It's even continued to guide after some (thin) clouds came over and obscured the stars completely to the naked eye - much to my surprise. I'd switch to 50mm finder-guider if the weight became a limiting factor (and/or then upgrade mount).

[PhotoGav]

Now you just need Astrotortilla and you really will have mission control sorted out - why faff about looking for your target when the computer can find it for you? (Oh and a second computer or tablet/smartphone with Teamviewer, a sofa, a big screen TV, a pipe and some slippers; then you can sell the picnic table and deck chair!)

Don't worry Astrotortilla is on the list...

As for joining the 'never look up astro photographers group' - mmm...!

Sent from my iPhone using Tapatalk

[Mr Bergman]

Optical Path, Photogav, IanL, Louis JB, Olly, Freddie, James,  thank you very much for taking time helping me! The qhy5L setup sounds really nice with off axis guiding....and PHD sounds excellent. And also free!

I also discovered that OAG ain´t much more expensive than other setups as I first thought. Question; In how low temperatures have you been outside guiding  with your laptops?? I live in Sweden, with winterconditions from -10 to -20 c. 

I image with a Canon DSLR, but without coma corrector for now. I guess something like this should do the math? Only question is backfocus etc.?

OAG;  http://www.astrosweden.se/sky-watcher-off-axisguider/20597-0

CAMERA: http://www.astrosweden.se/qcam5l-ii-farg-planet-och-guidekamera/20577-0

Total price; 300 euro approx. Which is far cheaper than other setups! And also this camera will serve as a planetary buddy. 

[IanL]

I use whatever the cheapest laptop is that they have on offer when the previous one breaks.  This one has been going for two and half years (previous one was just an old work one but it was so slow I had to change it).  I use mine in temperatures down to -5c which is about all I can stand, never mind the equipment!  If I take it outside in winter and set up before dark, it does not like to start if it has got too cold waiting (I think one of the fan bearings seizes and the diagnostics won't boot the machine), so I tend to start it indoors and let it get warmed up before taking outside.

The main hazard round here is dew formation on the case, the screen, the keyboard, everything really.  Some nights there is liquid running everywhere.  Not so bad if it freezes though, until you take it in and warm the thing up.  To be honest I need to make a little laptop shelter (some corrugated plastic packaging sheet would be ideal).  That would keep the dew off as well as shielding the screen from the scope.

The main trick is to make sure you start it up in the warm, dry it off before bringing indoors and (assuming the moisture stays out of the case) keep it running until everything has evaporated indoors.  That should prevent any moisture forming inside the case.  Of course I always use an RCD in case of unexpected earthing, and I put all my mains electrical cabling inside a modified tool chest except the main plug in to the extension (which I do shield from the dew).  Of course a purpose installed external power point would be better still.

[Mr Bergman]

IanL - I have been thinking about the dew, maybe one could use a padded plastic case to fit the computer, which I then close when guiding is up and running, to get less dew. Winters in Sweden is really cold, so I´ll need some protection. 

btw - I´ll use your imaging toolbox, looks nice! 

Erik

[Sp@ce_d]

Just to add another voice to the thread. I have 3 types of guider setup, ST80, finder/guider & recently added OAG (incorporated into filter wheel). Like others have said I'd also go straight for the OAG for a MN190.

I also run the entire obsy off a remote controlled netbook.. That's running 3 imaging CCDs!

I now Scotland's not "normally" as cold as where you are but the gears permanently in that environment. As for batteries, I hear the Tracer ones are getting good reports & are light enough.

Sent from my iPhone using Tapatalk

[Mr Bergman]

Just to add another voice to the thread. I have 3 types of guider setup, ST80, finder/guider & recently added OAG (incorporated into filter wheel). Like others have said I'd also go straight for the OAG for a MN190.

I also run the entire obsy off a remote controlled netbook.. That's running 3 imaging CCDs!

I now Scotland's not "normally" as cold as where you are but the gears permanently in that environment. As for batteries, I hear the Tracer ones are getting good reports & are light enough.

Sent from my iPhone using Tapatalk

Thx Sp@ce_d. Nice to hear that the gear works good in cold environments! Thats nice to know....I guess I´ll be out in really cold winternights to come. 

Seems everyone speaks for off axis guiding, so I guess that´s what it will be later on! I made a list now with gear to order when my wallet permits. Off axis guider and most likely a QHY5 camera. 

[Mr Bergman]

What do you think about this one?

http://www.teleskop-service.se/sv/astrofoto/guideteleskopautoguiders-mm/off-axis-guider-direktanslutning-canon-eos.html

/Erik

[Mr Bergman]

Oups, only Swedish....however, 11mm total build with it on my DSLR, which gives room for a coma corrector as well. Seems nice. 

[Mr Bergman]

So here we go; ordered a QHY5L Colour + adapter for finderscope:-) I was at first thinking of an Off axis, but decided to use that in the future and start with this setup instead. 

Thank you all for ideas and thoughts! 

[PhotoGav]

Well done and good luck - I look forward to seeing the first results!

[ollypenrice]

Now you just need Astrotortilla and you really will have mission control sorted out - why faff about looking for your target when the computer can find it for you? (Oh and a second computer or tablet/smartphone with Teamviewer, a sofa, a big screen TV, a pipe and some slippers; then you can sell the picnic table and deck chair!)

While I've nothing against Astrotortilla it is perfectly straighforward to find your object without it. Just re-synch your mount on a nearby star, if your GoTo is not all that accurate, and send the mount to the RA and Dec of the target as framed up beforehand in a planetarium software. This could hardly be much more simple.

Olly