First light GSO10RC and G11

[telecasterguru]

Well the couds cleared for a couple of hours tonight and at last I was able to put the G11 together and plonk the GSO 10" RC onto it. This is the first time I had used either the mount or the scope. Previously I used an EQ6.

I did not image tonight. That would have been too much what with trying to learn the mount and the scope.

Firstly, the G11 had no problem with the 10" and the ED80 and threw them around with what appeared to me to be ease. I weighed the 10" on the bathroom scales and it came in around 16 kilos. I was a little surprised as it didn't seem that heavy to pick up.

I was worried that balancing the scopes would be a problem, but is was not, although 2 x 21lb weights were needed. That's around 20 kilos!!

Using the hand controller on the G11 was a real learning curve. It is absolutely nothing like the EQ6. I am not sure whether it was better or worse, just different. It did take a while to work out how to find the different menus but after I had sorted that it wasn't too bad.

I connected a Garvin GPS unit and the mount downloaded all the information required and away I went.

Three star alignment was not too bad from a standing start. Sirius, Canopus and Rigel.

The manual says that you have to use three stars all on the one side of the meridian. This was OK as these bright stars are all easy early in the evening.

I have to say here that the manual is very good although a little bit too much information at times if that is possible.

Problem came later in the night as they moved past the meridian and I wanted to realign. Sorry, that star is not availalbe.

The real problem that I had is that I you have to do a polar alignment before you do the star alignment. I did not do this and was therefore having star alignment problems. The clouds were rolling in and I was getting impatient. Need to remember to do the polar alignment next time.

This of course meant I was not finding targets as easily as I would have liked. Not far off but a little.

All in all the G11 looks to be the goods. Still a long way to go to learn all of the little idiosyncrocies of the mount but pleased with the first go.

Now the GSO 10" RC.

This scope looks great. It has no manual supplied. I did not find this a problem.

It comes with 2 extension tubes for the focuser and you definitely need the longer one to find focus. I could not find focus at all with out it. I thought that this was very odd to produce a scope that the focuser could not be used at all without an extension. Having said that the extension was very solid.

I could not find focus at all with a diagonal. Not with any of the extensions or without.

My first view of Sirius nearly blew my socks off. I thought I may have to collimate the secondary mirror but defocusing did not appear to show any displacement in the mirror. I was more than suprised and also very happy after all the talk about collimation that I had read.

Next a quick look at M42 as you would expect. There was an enormous amount of detail in the nebula and I know this is not supposed to be a visual scope but I was more than happy with what was in the eye piece.

I would say that it appeared to me to be sharper than my 10" dob. I suppose, I really expected it to be. The dob's mirror is fairly dusty but that is another story.

The full moon is on its way and the clouds roll in and the show is over. Would have liked to get to other objects but am very glad that after 2 weeks I could actually put it all together and start my steep learning curve.

I am very happy and next comes the imaging. Hopefully next weekend.

Frank

[Tandum]

Geez, 16Kgs is a lot heavier than I thought they'd be. This 10" GSO dob I have here is 20Kgs with losmandy plate, rings, finder and ML focuser. Looks like you'll need a G11 at least to throw it around. Hope it clears up for you by next week-end Frank.

[allan gould]

Nice post Frank, you will learn to love the G11 as it's a great mount. It has it's eccentricities but that is mainly in the handset. As you said it's all in the manual which will save you time and again.
Allan

[leinad]

Setup looks great!
I hope to get a G11 with Gemini GOTO in a few months.
Can't wait! :)

[Octane]

Congratulations.

Looks like a winning combination.

As mentioned, once you get used to the G-11/Gemini, you will love it.

I don't bother with doing any aligning up first. I do my drift align first. Then, counterweight down, turn the Gemini off and on, and then start the alignment procedure.

H

[multiweb]

Wow! Very nice. You're gonna bring it to Crago next night out? :thumbsup:

[Omaroo]

Great stuff Frank :)

May I ask what power are you supplying to the G-11? I had constant RA stalls on mine when it ran 12 volts straight from a deep cycle car battery which is why I went back (then...) to the standard Digital Drive electronics and steppers rather than Gemini and servos. Not everyone finds the same problem, and it is mostly sorted with power supplied up around 14-16vDC. Anyways - you're running a heavy-ish apparatus, so i thought I'd ask.

[telecasterguru]

Thanks everyone for the kind words and encouragement.

Marc, If I am allowed out I will be there as I was hoping to ask some questions about the G11 and the best way for guiding.

Chris,

I used mains power cause I am at home with a Powertech 1.5 Amp Regulated DC converter from Jaycar. The manual says to use 3 Amp but I haven't had any problems.

Frank

[strongmanmike]

Well Frank...that's excellent, what a nice looking outfit :thumbsup:. As Humi says once you get used to the mount it is sure to be a fine sytem to use. How did the focuser/extension tube feel as far as solidity goes?Where did you get the gear from? How much the scope?

Mike

[telecasterguru]

Mike,

The focuser felt OK and could be locked in place and felt quite secure when locked. I put the 5D Mark II on the focuser to get a feel for it and it didn't seem to be a problem with the weight at all. Locking the focuser into position with the camera I felt no slop. Although I still may get a Moonlight or Feathertouch but I will have a better idea when I get a chance to image.

The extensions are solid metal and no problem at all.

The mount came from Bintel and the guys there were fantastic in running me through the setup. I still don't understand the limit setting yet but I had no problems with the limits last night. A bit confused about limits actually.

I purchased the OTA from Andrews and once again the service was excellent.

The prices are on their websites.

My next issue is a specialised CCD camera but looking at the market at the moment I think there will be movement in the price of these in the next couple of months and also there are a few new imagers coming on the market. Probably a KAF8300 based camera may suit this scope but am happy for advice on this as I have no experience of CCD cameras at all. Maybe one of the 2mp cameras would work well. Definitely will be mono.

I will stick with the 350modded and the 5D for the present.

Frank

[Paul Haese]

Frank, sounds like you are onto a good thing. I knew there would be no problem with the scope.

CCD, don't go for the KAF8300. Your sampling will be way too over sampled. My suggestion and this is what I am looking at long term is the 6303E in the STX. Much more expensive but sampling will be better. I am currently around 0.68 and want something around 0.83. My seeing can peak at 0.70 or better but the well depth of the larger pixels will mean tighter stars and a larger field of view from the size of the sensor.

[telecasterguru]

Paul,

Sounds OK but the price is a bit of a problem.

Might start a new thread on CCD camera use.

Frank

[spacezebra]

Great report Frank

Looking forward to your images.

Cheers Petra d.

[DavidU]

Awesome setup there Frank !
Congratulations :thumbsup:

[wasyoungonce]

Watching posts & discussions with interest! Keep'em coming boys!:hi:

[tlgerdes]

Hi Frank,

You can go and get GCC for your G11, it will allow you to set some of the esoteric parameters (like limits) at little easier.

When will you bring it out to Wiruna?

[telecasterguru]

Trevor,

Thanks for the tip and I will definitely be at South Pacific Star Party but that is not until May.

I find it easier to get to Crago. Also am currently battling to have a couple of trees removed from my place as they are riddled with white ants.

This would make life a great deal easier.

Frank

[Manav]

Hi Guys,

Just out of curiosity what are the weight limit for the G11 compared to the EQ6 pro? Surely the EQ6 can handle the GSO10RC maybe not as well as the G11.

Frank: Nice setup :) Cant wait to see your images in the near future.

TC

[tlgerdes]

Courtesy of the Losmandy website

Instrument weight capacity 60 lbs.

[telecasterguru]

As trevor has pointed out, the G11 has a carrying capacity of 60lbs which works out at 27.21 kilos.

From my internet research, the EQ6 has a carrying capacity of 40lbs which works out at 18.14 kilos.

As I said, when I weighed the 10"RC on my bathroom scales they came in at nearly 16 kilos which doesn't leave much room on the EQ6. The OTA sure doesn't feel like 16 kilos to me though.

Frank

[TrevorW]

Frank

You've got to put only the tube on the scales mate not yourself

Cheers

:D:P;)

[leinad]

Bout right, they are advertised as 34.4lb; roughly ~15.7kgs.

[tlgerdes]

I think you might have one of those "FAT" scales. You know the ones that always indicate more than what you think. I have a set of those in my bathroom, it always says I weigh more than I feel I am.
:lol::lol::lol:

[Paddy]

Congratulations Frank. I very much look forward to some images. Perhaps some Arps?

[telecasterguru]

Paddy,

Thanks and arps are my ultimate goal. All of them but not all at once.

Frank

[Paddy]

Fair enough, 'twould be quite a task!

[gregbradley]

"CCD, don't go for the KAF8300. Your sampling will be way too over sampled."

Is there really such a thing as oversampled? The only consequence as I understand it if your pixels/arc sec is less than about .66 seeing is less sensitivity.

Also limited by your local seeing assuming you will always image at the same location.

The real danger is undersampled and lowered resolution isn't it?

Image scale is really another consideration and one chip doesn't do all jobs especially if you have multiple scopes. This why I have 2 CCD cameras.

On another topic I see at OPT they are advertising a 12 inch Astrotech RC now.

This is getting interesting.

Greg.

[AlexN]

I'd agree with Greg there.. Oversampling is good... Any negative affects can be controlled during processing of data.. Oversampled data tends to go through deconvolution a hell of a lot better in my experience.

Image scale is a factor that needs to be considered. Although at F/8 the focal length of the GSO 10" RC is not overly long.. 2000mm is longer than your average amateur photographers focal length, but its still a moderate focal length.. the KAF8300 would provide a good field of view.. Very usable, and given you want to chase PNe's and ARP's, the smaller pixels give you a larger image scale (pixel resolution) than a sensor with bigger pixels..

I would worry about the well depth of the 8300 though.. Chasing the real small, dim targets might be difficult with an 8300, as going much over 10 minute subs can cause star saturation... I've done a little testing on this myself, however Greg has done quite a lot of work with his 8300 and assures me that 10mins in the optimal exposure duration for the 8300, a few exposure calculators that I've checked out indicate the same..

If you want a serious CCD for that scope. Look no further than the KAF-3200ME found in the FLI ML3200/PL3200, SBIG ST3200/ST10XME

[gregbradley]

Yeah a FLI ML3200 could be a hot camera for that setup.
The 8300 does have small wells but there are lots of images now that
show pinpoint stars. On brighter objects shorter exposures than 10 mins are the go and in a scene with lots of bright stars as they spill over from the small wells first and can look a bit bloated. Same with any camera though but more so with this chip due to the small well capacity.

I wouldn't get a Proline for this scope as that camera needs a beefy focuser unit to handle all the weight and I doubt this scope could handle that (only a few can). So get a light camera whatever you get.

Greg.

[Paul Haese]

Point taken, I should have worded this differently. I think one can over sample at some point and you gain nothing by doing so. That said, I should have wrote that well depth when short can create bloat at certain exposure levels, and while it can be dealt with in processing, it is probably best to match the CCD with the scope from the beginning.

Alex, I remember you suggesting to me that I should go further than 10 minutes on my subs several months ago. Have you since changed your tune? This was what I was saying all along. The well depth on the 8300 is just too short to go for really long subs on a larger aperture scope. Saturation just kills the stars. So objects like Thors helmet really require a greater well depth than what I have.

Greg, yep sometime in the next year I will be getting one of the 12 inch scopes at near half price, due to the "effort" I have put in for GSO advertising. Looking forward to a nice large scope like that.

[AlexN]

Paul - With regard to LRGB imaging yes, I have changed my tune, 10mins is the go. When we're talking about Ha imaging, which we were at the time, i still think 20 or even 30 mins is the go.. I ran a some 20min subs in ha at F/4.8 that were fine. with broad band filters there is just too much light for that..

Good to hear you're getting a 12" on the cheap for your work..

[Exfso]

Hey Paul, does this mean I am going to have to make you a 12" lightbox for this scope...;)

[Paul Haese]

Alex, yeah that makes sense for Ha imaging.

Peter, maybe, but it will not be for a while yet.

[telecasterguru]

Gawd,

I've only seen through my scope once and already its redundant.

Bring on the 12" I say. Suppose I will need an AP1200 to carry it.

Next year looks like a new scope and mount again. Where will it end?

Frank

[AlexN]

Frank, Thats a very "Me" comment to make! :) If you're looking to move up in 12 months I'll take this shiny rig off your hands :)

I dont see it ending to be honest.. I think if GSO find they can reliably create 12" F/8 RC optics, they will go for 14" or 16". The same thing happened with Newtonians. Once the 8/10/12" Dobsonians were at a point where the optics were reliably very good, the 16" was put into production...

I reckon you'd get away with a 12" RC on a G11 depending on the rest of the setup. Going purely by weight, a Planewave 12.5" CDK + STL11002M/remote guide head/AOL and MMOAG setup falls within the weight capacity of the G11... I don't know how accurate the mount would be with that weight on it, however thats why I added AO into the equation..

I reckon you'd get the 12" on a G11, pure speculation on my part considering there is no expected weight specifications for the 12" just yet. I do not see the 12" being much over 25kgs considering the 10" is approximately 16kgs...

[MuntiNZ]

Mate I heard by Astronomics in the USA all ready that Astrotec are making a truss 16" version.
Sposed to be round 8000 American.
Are the Astrotec versions the same as GSO but different stickers or what?

[AlexN]

GSO are Astrotech's OEM supplier for a lot of items, although Astrotech make certain modifications to the products as they see fit which USUALLY are worth while... Take the GSO 8" F/4 Newt.. Good imaging scope, The Astrotech 8" F/4 Imaging newt - Great imaging scope.. The difference is that the AT model has a tube that is 9.4" longer, giving the scope a built in dew shield, and the extra contrast that goes with that.. And also, 15 knife edge baffles running down the inside of the OTA to stop off axis reflections...

If Astrotech are advertising a 16" truss RC, it is highly likely that GSO are making the optics..

[Paul Haese]

Only up to the 10" is being advertised on the Astro tech site.

Click Here (http://www.astronomytechnologies.com/listing.asp?o=10607&b=t)

The 12" will be demonstrated at NEAF this year and put into production next year.

[MuntiNZ]

Jeebus it took me a while to find the posting it was on Cloudynights about the 16" but here it is .....

AT16RC (http://www.cloudynights.com/ubbthreads/showthreaded.php/Cat/0/Number/3559185/page/0/view/collapsed/sb/5/o/all/vc/1)

[AlexN]

Yes Astronomics have confirmed that the 16" truss is in the works...

They are hoping to have it released by the end of this year, at or under $8000 USD, weighing in at 70~90lbs..

For 8K US you could do a HELL of a lot worse! :) For someone like Paul with his EM400 or anyone currently using a PME/AP900/AP1200 etc, that could be a SERIOUS imaging scope at a very nice price..

[MuntiNZ]

Yeah mate it said all that in the thread.

[telecasterguru]

Count me in.