GSO RC real image test

[mick pinner]

hi Mark, regarding the mirrors l hope your right.

[marki]

Originally Posted by 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

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]

Originally Posted by mick pinner

hi Mark, regarding the mirrors l hope your right.

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.

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 (Frank)]

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]

Originally Posted by 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

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]

Originally Posted by TrevorW

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

Don't forget Optical Guidance Systems (OGS).

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.

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]

Originally Posted by Zaps

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.

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]

Originally Posted by 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

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 (Dave Pastern)]

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

Originally Posted by 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.

[Satchmo]

Originally Posted by marki

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.

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

Mark

[marki]

Originally Posted by Satchmo

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

Mark

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]

Originally Posted by marki

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.

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

[marki]

Goodo

Mark