Joseph Gillman
Carpal Tunnel
Reged: 12/06/05
Posts: 2342
Loc: Boothwyn, PA
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So I'm pondering hypothetically (wink wink) acquiring a 10" LX200R to do a shootout with my RCX and I'll get some impartial people together to see whether thr R optics and RCX optics are indeed the same or really close. The 10"R f10 actually has a longer focal length than the 12" f8 RCX. other than that I can think of making a mas for the 12 which would actually handicap the rcx a bit with its bigger central obstruction. should I make the 12's mask a little bigger than 10 to compensate for this? should I not bother with a mask at all if it would introduce extra diffraction? I would test with and without mask of course. what else should I think about? what sky objects to compare to? I couldn't pick up the R till january anyway so I have some time to plan. unfortunately I won't be near my rcx either so I can't take measurements to plan this out in advance.
I have a stilletto focuser with 300 lpi ronchi screen, will this help? or will it only compare on axis performance?
any thoughts will be appreciated.
PS I can't keep both and I really want to hold onto the rcx so I think the R will just be a rental.
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Meade RCX400 30cm --
People dont like when I stick up for Meade but they're just jealous of my RCX 
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JAT Observatory
Space Freak
Reged: 02/20/05
Posts: 5652
Loc: Eastern PA
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If your going to all that trouble and your talking about a rental why not just get a 12" R so the test will be meaningful.
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-Marcus
The problem with free speech is even the stupid have a voice.
http://jatobservatory.org
12" LX200R on a Paramount ME
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Joseph Gillman
Carpal Tunnel
Reged: 12/06/05
Posts: 2342
Loc: Boothwyn, PA
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Simply put, a used 10" is available closeby, if I answered Morris' ad in time. if I buy a new scope it would be an expensive rental since I'd sell at a big loss. Much cheaper to "rent" a used scope.
Anyway the shootout would take place near west chester PA with very nice (for the philly area) reasonably dark skies. You're definitely welcome to join in the fun. A more experienced astronomer like yourself would be quite beneficial. Also if you've never looked through R or RCX optics you can give an impartial opinion, whereas I would probably be "rooting for" the RCX.
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Meade RCX400 30cm --
People dont like when I stick up for Meade but they're just jealous of my RCX
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JAT Observatory
Space Freak
Reged: 02/20/05
Posts: 5652
Loc: Eastern PA
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I ahve never viewed through either a R or RCX. I have been considering a 10" R OTA to replace my 10" GPS. That would allow me to reinstall my GPS back on it's forks and sell it.
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-Marcus
The problem with free speech is even the stupid have a voice.
http://jatobservatory.org
12" LX200R on a Paramount ME
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Ben Ritchie
Lost in Space
Reged: 01/31/05
Posts: 4339
Loc: Bosham, UK
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Given that it's fundamentally not a like-for-like test, working at roughly the same focal length doesn't seem unreasonable (2400mm for the f/8 RCX, 2500mm for the f/10 'R'). Obviously the RCX is going to catch some more light, but hopefully it's possible to draw conclusions despite that. You could (in theory, anyway) do 10" vs 10" or 12" vs 12", but then you're working at quite different focal lengths and I get the feeling that things like seeing might come into play. Dunno, i'm no optical tester.
One thing i'd suggest is a CCD and a copy of CCDInspector. Side by side under the same conditions that'll give some interesting figures, and will tell you things that they eye isn't going to see.
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Astro-Physics 130EDT StarFire, 80ED (x2), 305mm f/5 dob, VLT
Astro-Physics 1200GTO, evolved HEQ5/pro
Coronado SM60/BF10, 3-6 Nagler zoom, 8 & 13 Ethos, 28UWAN
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Joseph Gillman
Carpal Tunnel
Reged: 12/06/05
Posts: 2342
Loc: Boothwyn, PA
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Good point. Is an ST10 sized chip big enough to judge the performance, or should I find someone with a bigger chip? I have a DSLR we can use I think it's an APS size sensor. This might be a good excuse to sign up for the 30 day ccd inspector trial.
Ben I thought of making a 10 inch aperture mask for the rcx, see my original post. then you'd have 2 scopes still at very similar focal length and now at the same (almost) aperture. the rcx 12 has a much bigger central obstruction though so if anything the rcx would be disadvantaged with a 10" mask. should I calculate the aperture required for the mask to yield the same light gathering power based on the different central obstruction sizes? how flat should a mask be in order to not introduce more aberrations? both scopes will have an eye opener 2" visual back.
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Meade RCX400 30cm --
People dont like when I stick up for Meade but they're just jealous of my RCX
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Sisyphus
member
Reged: 12/02/07
Posts: 29
Loc: Norman, Ok
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You are going to need a large format chip. If any appreciable difference is going to show up it will most likely be at the edge of the field. Probably more coma in one than the other is about all you might detect that could be attributed to differences in design and not intrinsic variations in optics. I have not looked thru a RCX, but considering how good the 200R's performance is I don't think you will find much difference other than the obvious differences between an F/8 12 inch scope and an F/10 10 inch scope.
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12" Meade LX200R
Denk Power Switch S2 w/Filter Switch
Meade Series 5000 UWA 30mm, 18mm, 6.7mm
Meade Series 5000 Possl 26mm
Pentax XW 5mm, 7mm, 10mm, 14mm, 20mm, 30mm, 40mm
2" Badder Moon and Skyglow Filter
2" Badder UHC-S Filter
...all the bells that ever rang still ringing in the long dying lightrays...
-William Faulkner
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Joad
Wordsmith
Reged: 03/22/05
Posts: 11919
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Even a qualitative visual comparison would be interesting to me. If there is an immediate WOW! difference at the eyepiece between the two, that would be useful to know. If there isn't, that would be useful to know too.
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Nick Cook
Pooh-Bah
Reged: 01/28/06
Posts: 1035
Loc: Somerset, England
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Faster optics 'should' make a difference to visual observation...
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Meade 14" RCX + Astro Physics 0.75 Reducer (27TVPH)
Meade 5000 ED80 APO (Guider/widefield)+ WO 0.8 Reducer
William Optics Zenithstar 66 Petzal
SBig STL11000M + AO-L + 3" Pyxis Rotator + 3" PDF Focuser 
Canon 20Da + IDAS Filter
Pulsar 9ft Dome
www.nick-cook.net
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Joseph Gillman
Carpal Tunnel
Reged: 12/06/05
Posts: 2342
Loc: Boothwyn, PA
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Happy New Year everyone!!!!!
I have Morris' old LX200R 10 in hand. Just looking at it on the table, it seems like they beefed up the fork arms compared to the LX200GPS, they looked as wide as the RCX400, but that could be my bad memory.
Nick, what I am after here is the answer to, "Is the RCX more 'APO-refractor-like' than the R?" Or, is all you get fpor the extra money with the RCX the electric collimation and carbon fiber tube?
SCT's have been basically f10 with few exceptions for the last 35+ years right? Maybe this comparison correlates to refrtactors, where an f8 APO is worth more than an f10 APO, but maybe not. (These days, f5 vs f7, 8 vs 10 refers to the Meade scopes)
If the views are just as good with the R, do I keep it and sned the RCX to its next loving home? Is the RCX more likely to be a rare scope in the future?
I am tired from a long car trip, so sorry for the extra misspellings!
Decisions....
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Meade RCX400 30cm --
People dont like when I stick up for Meade but they're just jealous of my RCX
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Joad
Wordsmith
Reged: 03/22/05
Posts: 11919
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We're looking forward to the comparison.
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Moggi1964
Carpal Tunnel
Reged: 11/07/05
Posts: 2512
Loc: Madison. NJ. USA
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So am I!
What I want to hear is that the RCX blows the R away and then I can feel good about letting the R go
Truth be told I HAD to sell it (NJP purchase) and a further truth would be that I hope it performs pretty *BLEEP* close to the RCX so that in a few years from now when Meade is back on its feet I can buy a used R and mount it on the NJP.
Enjoy it Joe and know that you have an interested audience.
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Morris
WO Megrez 80 ED F/7
WO 8x42 binoculars
Seymor Rosin F/4.5 Astrograph in the making
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Bob Moore
professor emeritus
Reged: 04/07/06
Posts: 543
Loc: New York
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Post deleted by Bob Moore
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R.A.C. Advisory Committee
NEAIC Co-Chairman
NEAF Advisory Committee
http://deer-pond-observatorie.wetpaint.com/
Warwick, New York
41.15984 -74.2541
Losmandy G11/Gemini
TAKAHASHI MT-160
10" F4.5 Newt
Vixen R200ss
Orion Starblast
Astro Tech 80 ED
Astro Tech 66 ED
Coronado PST H alpha
ToUcam pro,& DSI Pro II, SX MX716,QSI 532
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Joseph Gillman
Carpal Tunnel
Reged: 12/06/05
Posts: 2342
Loc: Boothwyn, PA
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Let's stay on topic.
This thread will be about the optics (and fork mount too) of the LX200R and the RCX400. Not the availablity of them now or in the future, and not about Meade the company.
Darnit Whether or not Meade is on its belly as you say has ZERO to do with the title of this thread!
I won't comment further in this thread if this is going to revert to a "Meade financials thread" YET AGAIN.
Quote:
Cloudy Nights is not an open air forum for vendor complaints. If you seek resolution, it is recommended you talk to the vendor. If you seek an audience, it is recommended you go elsewhere.
Posts with the intent of “creating a reaction” are not welcome here (no “trolling”).
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Meade RCX400 30cm --
People dont like when I stick up for Meade but they're just jealous of my RCX
Edited by Joseph Gillman (01/02/08 01:13 PM)
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Joad
Wordsmith
Reged: 03/22/05
Posts: 11919
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Joseph is right. I try not to interfere too much with this forum, but it's high time we stayed on topic. I've edited a post accordingly.
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snufus
sage
Reged: 09/10/05
Posts: 379
Loc: Round Rock, TX
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Joe,
I cannot wait to read your report! I did a comparison (visual only so far) between my 12'' LX200R and 12'' LX200 Classic and I was very surprised to find that the good old Classic held its own! Only on the extreme edge did the R win out. As for contrast, brightness, and pin pointness (lol, if that is a word) of stars they were same as far as I could tell. I do expect though that once I begin imaging through both more differences will be seen (going positive towards the R).
I cannot to see what you find and thanks for doing this and sharing it with us!
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Best Regards,
Daniel
Scopes
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Meade 12'' LX200R #1
Meade 12'' LX200R #2
Orion Premium 102ED
William Optics 66SD
William Optics 66ZS
Mounts
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Celestron CGE #1
Celestron CGE #2
Meade LXD750
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katodog
Supreme Grandmaster
Reged: 03/31/06
Posts: 2301
Loc: Carol Stream, Illinois
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I'm very interested to see how this shootout develops. It would sure answer a few questions that have been lurking in my cluttered mind. I've always wondered if the things I was seeing through my LX200R were only looking incredible compared to other SCTs because I want them to, and not because of the "advanced" optical design.
One thing I really need to know, though, is why on Earth you'd want to shoot a telescope, and which one's first?
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The only stupid question is the one that goes unasked
12" Starhopper / Coronado PST
Stellarvue 20x85mm Binocular / LXD75 Mount
Sigma APO 150-500mm F5-6.3 DG OS HSM
Sigma 18-200mm f3.5-6.3 DC OS
Canon EF 70-300mm f/4.5-5.6 DO IS USM
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Joseph Gillman
Carpal Tunnel
Reged: 12/06/05
Posts: 2342
Loc: Boothwyn, PA
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I meant shootout in the "how do we unbreak a tie score in hockey" sense, or in the "shooting pictures" sense - no violence intended whatsoever!
Daniel, some of the older 12" classics (maybe all of them?) used white water glass for the corrector instead of BK7 like what they used in the LX200GPS line.
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Meade RCX400 30cm --
People dont like when I stick up for Meade but they're just jealous of my RCX
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Moggi1964
Carpal Tunnel
Reged: 11/07/05
Posts: 2512
Loc: Madison. NJ. USA
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Don't be too tough on Bob; he's a good friend who helped me stay in astronomy during frustrating times. He has been a real asset to me and anyone he comes into contact with in astronomical circles.
I'll have to ring him and ask him what he wrote
Anyway, back to the topic at hand........... are you going to be able to image through both scopes Joe? If so, what imaging equipment will you have?
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Morris
WO Megrez 80 ED F/7
WO 8x42 binoculars
Seymor Rosin F/4.5 Astrograph in the making
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Pess
(Title)
Reged: 09/12/07
Posts: 1910
Loc: Toledo, Ohio
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I can suggest a pretty good objective test you might try if you have both scopes while the moon is out.
For a hundred years this has been the standard for testing refractors: Train both scopes on the crater Plato on the moon and see how many of the craterlets you can count.
Ideally you need skies clear enough for the quality high mag EP's I know you have. If you are lucky your scopes could resolve 3-7 of them with good seeing and the right shadow angles.
I believe the GOTO's on your mounts can easily find this crater.
I'm throwing this out there as just a thought for consideration. You might even get lucky and image the mysterious 'fog' said to haunt the crater. 
Right now I am imaging Plato as practice whenever the lunar phases and seeing permit.
http://www.skyandtelescope.com/observing/objects/moon/3307211.html
Pesse ("And those whose hearts are fixed on Reality itself deserve the title of Philosophers." (Plato, Republic)) Mist
Edited by Pess (01/03/08 10:49 AM)
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