GSO RC real image test

[TrevorW]

Anyone interested check this link

http://www.cloudynights.com/ubbthreads/showflat.php?Cat=0&Number=3063505&page=0&view=collapsed&sb=5&o=all&fpart=1&vc=&PHPSESSID=

:thumbsup:

[toryglen-boy]

taken under the cirumstances described its a killer shot, although even without that its still great. Looks better than i expected

;)

[Paul Haese]

Despite the image looking like it is unguided or the guiding was a bit sloppy, this gives me hope for my scope. I have not yet imaged with mine.

Thanks for posting this Trevor. These scopes are looking ok. That should put the wind up some.

[TrevorW]

As an avid follower of the progress and sale of this scope it was with concern I read all the derogatory remarks on Cloudy Nights regarding the quality of this scope a lot of which I found was unfounded in the sense that the scope was being

a) advertised as a astrograph never intended for visual use and at $1400 US cannot and should not be compared to the

B) 10 and 12" RC's being made by RCOS or Plainwave.

and

C) was being made in Taiwan where labor costs are significantly less and as anyone knows its labor cost and markups that impact the most on the end conusumer cost of a product.

If the actual photographic results from the 8" show the goods then when the 10" is released in May and by all rights this should be under $5000 AUD or 1/2 the cost of an equivalent RCOS or Plainwave equivalent then what more can be said.

IMHO

[gbeal]

I agree, but the one thing that makes me shake my head is that this scope is virtually an imaging only scope (notwithstanding all the tyre kickers that frequent Pauls post on CN's asking about visual), and yet the designers God Bless them saw fit to make this guy with a normal CCD camera fit 5" of extension tubes. I mean come on. Design the thing with the average CCD in mind guys. Given an average focuser I suspect that most will suffer field flatness caused by the stock focuser sagging. I hope you can get around this Paul. Not impossible but easily avoidable I would have thought.
Gary

EDIT: This isn't a wind at the scope itself, I am actually very keen to see it work, nor the new owners, more a "why didn't they design it like this".

[TrevorW]

Possibly right here and I tend to agree that the one thing letting it done was the focuser and the focus travel but at the end of the day you can't expect a 3" Feathertouch, Moonlite or JMI or the likes on one for the price.

How many have upgraded stock focusers on SCT, Newts etc it seems to be where all manufacturers cut costs on their products this way, except maybe the more expensive APO refractors.

At the end of the day if I have to send another $500 on a decent focuser so be it.

Cheers

[marki]

One thing that has me a little perplexed is the often mentioned "labour is cheaper argument". From what I have read about the manufacturing process the optics are carved out by CNC machines and it seems the first time human hands touch them is to mount the optics into their mirror mounts. I am guessing here but I suspect asian govt's are offering far better deals to manufacturers then they recieve at home (taxation wise). The big name products are expensive because they can demand a premium based on their proven performance. That is not to say that the quality is not there, only the markup is greater. I would certainly love to know what the production costs are for an RCOS or similar;).

Mark

[TrevorW]

Lets go back to the Bonds Argument a pair of jocks made by Bonds in Australia cost $15 the same pair of jocks now made in China cost $15 or more. Has the manufacturing technique or materials used changed.

:shrug:

[marki]

Argh but Trevor imagine the bragging rights "even my jocks are CNC machined :D. Prices will move in respect to what the consumer is willing to pay and the cheeky buggers at bonds did not move OS for our benefit.

[TrevorW]

Well at least they support Australians in other ways

[marki]

When are you expecting your new scope to turn up? If it was me I would have ordered a moonlite at the same time :D. I am still going to wait for the 10".

Mark

[TrevorW]

Could be a week

I'll see how it goes with the stock GSO focuser first.

If need to replace may go with a 3" Feathertouch or JMI instead

Cheers

[marki]

Go with the feather touch rather than the JMI. With such a small baffle tube though I think a 3" would be wasted. If you really want a JMI I have an EV1 with smart focus which you are welcome to try. It has a large format visual back to suit the meade threads.


Mark

[Chippy]

I'm not sure about this, but from what I have read I don't think these RC mirrors are purely CNC machined. I think they require manual finishing to get the complex curves required. In which case labour cost is a major factor.

[marki]

G'day Chippy. I knocked this off from Trevors post below.

Computer designed and fabricated optics: To keep the cost of each Astro-Tech RC so reasonable when compared to competitive RC scopes, the computer-optimized Astro-Tech hyperboloid mirrors are automatically ground and finished to very high tolerances using custom-made computerized mirror grinding machines. This precision computer control guarantees an exact repeatability of figure from mirror to mirror that is difficult to achieve using more costly conventional hand figuring. After grinding and polishing, each mirror is individually tested using a Zygo interferometer to assure that it meets or exceeds its specified surface accuracy.

Mark

[Paul Haese]

When I bought mine, I spoke to Lee Andrews and he was saying that GSO has gone to considerable expense with CNC machines, which are used for grinding the mirrors. So this just confirms verbally what is written on websites (most of which can be taken with a grain of salt, especially in regard to sales being made).

Lee did not indicate whether the mirrors were hand figured in the last part of the process.

[Zaps]

Americans are very image-conscious and they earn a lot more than most, on average. They are willing to pay a lot more for stuff because expensive stuff has a "better image" than inexpensive stuff. The ol' vicious circle.

The upshot is that an American manufacturer such as RCOS or Astro-Physics know they can whack on a huge mark-up and Americans will queue to buy it: If it's expensive it must be (i) better than the less expensive stuff and (ii) a more desirable and prestigious thing to own.

But maybe I'm wrong. Perhaps it would cost GSO and Synta just as much to make an equivalent product as it does the expensive American boutique manufacturers.

[mick pinner]

as l see it RCOS and Astro Physics charge more because they make a consistently better product, that is the quality from one scope to the next is basically identical. the GS scope is cheap because quality is not guaranteed. the thing that determines the price of an article is far and away the effort and expense that is put into product development.
the new GS RC's from what l have read on the net seem to vary greatly in optical quality from one to the next which seems to indicate a lack of care in the way they are produced which goes back to the quality of the way they are developed in the first place.
l hope these scopes work but it is the consistency that worries me.

[marki]

Mick, it appears to me that many of the rumours about dodgy optics seems to be fueled by those that have a vested interest in this scope not working for what ever reason they may be. There was one bad bench test, thats all. The quality of pics being produced really put the argument to bed (there is a few good uns posted on CN). I have noticed that the optics are longer a real discussion point and all the tyre kickers are having a go at the focuser instead. These scopes will never be RCOS or AP equivilants but the real question is do they need to be? If the blurb I posted below is even remotely true then I would expect the mirrors to be of equal quality and far more so then manually figured mirrors.

Mark

[gbeal]

You're meaning the tyre kickers on this forum or CN's Mark?
Why I ask is simple, I made a broad statement about focuser sag, and I just hope you are not lumping me in the "rumours and vested interest in the scope not working" category.
Gary

[mick pinner]

hi Mark, regarding the mirrors l hope your right.

[marki]

Not at all Gary:). It just seems to me that everybody was running them down before they were given a chance to show if they could produce a decent image or not. My comment was based on a thread that was locked here not so long ago and the large number of detractors posting on CN (read pauls thread ).

Mark

[marki]

Me too Mick:). I have been quietly optomistic about these scopes and am seriously considering the 10" when it comes out. One things for sure, they certainly have stirred up a hornets nest:D.

Mark

[mick pinner]

l just hope people do not overlook any obvious shortcomings just because they are perceived to be cheap otherwise the manufacturers will not be forced to fix any problems as happened with the Skywatcher EQ6.

[TrevorW]

It's not unusual for RC's to have 10" or more back focus just check out RCOS and Star Instruments site.

If the GSO 10" RC comes in under $5000 AUD it'll still be more than $8000 cheaper than the one made by PlaneWave who make a 10" RC with CF tube

RCOS sells a 12.5" for $20000US

The only other manufacturer in the states Deep Sky Instruments sells a 10" RC with phelonic tube for $8000 US

At the end of the day the optics and rigidity of the CF tube and overall build quality will be the issue, focuser's can easily be replaced as can baffle tubes for that matter.

How many knockers were their when the 127mm Chinese ED APO's (which I believe I introduced to this site) could be purchased under a $1000 and so far I believe every one who has purchased one before the fall in the $$$ has been happy with the optics.

[telecasterguru]

I agree. Even though I have only had my ED127 a few days, I am very happy with the images that I have so far been able to come up with and I am also waiting for the 10" RC which I am hoping will be just as good.

Frank

[AlexN]

Planewave dont make RC's, they are CDK's, but thats neither here nor there I suppose.

These images are definitely comforting to see... I was going to have mine out this weekend past, however due to not being able to balance the scope, I was unable to use it... The scope is incredibly rear end heavy when there is 5" worth of extension tubes and the SBIG hanging off it.. The rear end of the scope is just far too heavy, and the dovetail doesnt extend far enough back for proper declination balance to be achieved. Far from it infact...

I've ordered a counterweight setup that attaches to the dovetail at the front of the scope to balance it up... NNNNEEEEXXXXTTTTT weekend... fingers/toes/arms/legs crossed..

[Zaps]

Don't forget Optical Guidance Systems (OGS).




Begging to differ, I inspected two 127s and neither were satisfactory. Tons of severe field curvature and a lot of CA. Others have mentioned the same issues in the samples they bought or used. True, there's no denying it was a low cost triplet, but overall optical quality-wise they are lacking. For the price, okay I suppose, but you get only what you pay for.

[marki]

Thats very interesting Zaps as the gents who bought them here were very pleased indeed and I have not heard one complain of CA or excessive field curvature although there was some talk about the focuser being a little on the inadequate side. To what may I ask are you comparing the 127 to?

Mark

[allan gould]

Be careful in what you are comparing.
Some of the ED127mm scopes had hand-figured Japanese FPL-51 ED glass as their triplet while others had the chinese machined figured "equivalent" glass in them. Some of the focusers I have seen were excellent while others were really abysmal. I changed mine to a Moonlight focuser but mine was not too bad. Some of the 127mm ED scopes had definite CA while mine had non visually - but that was the agreement that I had with the vendor. If it wasn't an APO, then it was going back and it had to have the Japanese glass in it. As another benefit mine has a very flat field covering a DSLR chip.
Im interested in the 10" GSO scopes as well as some others here. I guess that you have to know exactly what you are purchasing and if the focuser isn't up to scratch it will be replaced [but I expect that as several GSO focusers Ive had were not bad but did not hack it in the heavy weight division].

[dpastern]

I made a similar post on CN which was removed, no doubt due to the sponsor disliking the tone and content of my comments. There's no doubt in my mind that RCOS and others have huge markups on their gear. And there's no doubt that there's people out there silly enough to buy it.

Dave

[Satchmo]

I think I just saw a naked man walking down the street, wearing a crown, out of the corner of my eye :)

Mark

[marki]

Mark, I am not having a crack at you or others that are well versed in the black art of making fine mirrors. Notice I said "equal quality between mirrors" not better than a single hand figured mirror that has had an enourmous amount of time spent in its production. The argument has been about consistency of mirrors not that they are the greatest mirror available. Personally I would love to meet a human capable of grinding 30 mirrors a day to within a reasonable degree of ideal but I don't think this will happen anytime soon hence my comment. Some of the images now being posted put much of the speculation to bed.

Mark

[Satchmo]

I think you mean `equal standard' rather than `equal quality'.

[marki]

Goodo :thumbsup:

Mark