revans
Carpal Tunnel
Reged: 09/26/05
Posts: 1516
Loc: Fitchburg, MA
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Well, I know what you mean... but also we shouldn't stifle freedom of speech when at least it is pointed at something that can be justified in at least some way even if I don't agree exactly with the opinion expressed. As long as there is no rudeness or disrespect I think people should say what they think even if I don't agree...
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Rick Evans
http://www.freewebs.com/revans_01420/
"The universe is there for us to see, but it cannot be understood without learning its language -- mathematics." Galileo Galilei
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Bob Abraham
super member
Reged: 05/17/05
Posts: 115
Loc: Toronto, ON, Canada
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Getting back to the original topic. I've got a Mewlon 180 and have
compared it extensively to similar aperture Maksutov-Cassegrains and
apo refractors. I enjoy all these telescopes. In terms of pro and cons,
here's my take on my particular Mewlon:
Pro:
- superb optical quality
- excellent images on-axis
- extremely light weight and easy to mount
- extremely easy to move around because of the finder/handle
- holds collimation very well
- almost never dews up
- open tube so acclimitization is fairly fast (though see note
about tube currents).
Cons:
- strong coma inherent in the optical design. I use it for things
where on-axis image quality is most important. It would not be my
choice for mounting alt-az as a quick look scope though, and you
do need to be fastidious about getting collimation right.
- open tube so tube currents are occasionally visible on nights when
the temperature is dropping quickly.
The business with dust on the optics is a non-issue in my opinion.
Dust collects on exposed optical surfaces in any design, and while I do
feel dust on reflective optics is somewhat worse than dust on transmissive
optics (due to the direction of scattering), the primary of the
Mewlon is at the base of the tube which is sealed at the bottom,
so it collects less dust than the objective lenses of my other
telescopes (e.g. my Mak). So the Mewlon needs cleaning less often,
if anything. Also the mechanical construction of my Mewlon is such
that cleaning the primary of dust is a 5 minute operation which
leaves collimation unaffected.
Bottom line: I find Mewlons wonderful telescopes with some
strengths and some weaknesses, just like any optical design.
On balance, I prefer my 8" Mak to my Mewlon 180, but the
latter is much more portable, so they are somewhat
complementary. The only scope I would consider trading my
TEC MC200 for would be either a 10" TEC Mak or a Mewlon 250.
Bob
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Fomalhaut
sage
Reged: 08/16/08
Posts: 243
Loc: Switzerland
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Bob,
Excellent post - sums it all up 
Chris
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Currently:
Tak FS-60c (guidescope for:)
Tak FCT-100/640 on Tak EM-10
Tak Mewlon-180 on same
IntesMicro-M500
Zeiss 7X42-T*P-Dialyt + Nikon 18x70 Binoculars
Coronado Maxscope 40
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LLEEGE
Running out of Oxygen
Reged: 03/03/05
Posts: 9079
Loc: Cloud-chester,NY
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I deleted some offending posts. Any further insults or accusations will result in a lock.
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"Okay! You draw the straws. I'm-a taking the parachute."
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Bowmoreman
Post Laureate
Reged: 09/11/06
Posts: 3996
Loc: Bolton, MA
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best view of Jupiter I have EVER had was through my neighbor Steve's Mewlon 300... amazing detail, perfect Moon transit...
We're I into planetary, doubles and astronometry of doubles, etc... it would be on my list...
But, I'm kinda a wide-field/fuzzies guy...
clear enough skies
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Dave
Imaging: MI-250+ADM/SBS/Optec Libra: C11Hyperstar,TMB80SS
Visual: XT10i RTP
TV: 31T5,22T4,17T4,12T4,13Ethos,8Ethos;2x Powermate,Paracorr, 1.6X Antares, Hyperion8-24Zoom
Cameras: Mallincam Color Hyper Plus, QHY8
Guider: SBIG STV eFinder
Key Add-ons: Gerbings Heated clothes, WilderSkiesObservatory(BYO#90), Speco 9"Monitor
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isramirez
Pooh-Bah
Reged: 11/04/05
Posts: 1391
Loc: Mexico City
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Quote:
I deleted some offending posts. Any further insults or accusations will result in a lock.
Well i can forward to you the kind of PM i received today but i also want to ask you please to lock, ban or delete my CN account 
Thanks in advance!
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maknewtnut
Vendor (Teton Telescope)
Reged: 10/08/06
Posts: 859
Loc: SE Idaho
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Israel. I know this is a tough sell, but consider hanging in there. Many of the most experienced have left this site, myself included. I however opted to return, which has not been a completely smooth road, but still worthwhile if it results in helping to further the understanding of a fellow amateur astronomer or two now and then.
I know your reactions were likely the result of what was perceived as claims that an open tubed scope does not collect as much dust as other design types, but perhaps there was something lost in translation. I know that is the likely cause for ill words directed at me recently. Other causes include brand loyalty, which it appears is how you may have taken comments.
In either case, here's a tip that might make staying worthwhile. Stick to stating fact and offering sound opinion. If and when someone disagrees, let them. Over the past year I've learned there are more folks watching and reading that are able to come to common sense conclusions than you might think when it's perceived you are fighting a noble battle.
Contributors to this forum may take for granted the number of unbiased minds reading, many of which do not reply to a discussion. Many appreciate when corrections to misstatements is presented and/or when experienced opinion is offered.
Spending just a little less time at the PC doesn't hurt either, especially when you feel your blood pressure lower as a result. Give it a try. With a title that included "...Love or Hate?", it was bound to happen.
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Mark
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LLEEGE
Running out of Oxygen
Reged: 03/03/05
Posts: 9079
Loc: Cloud-chester,NY
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Quote:
With a title that included "...Love or Hate?", it was bound to happen.
Yep. But as long as the conversations are polite, all opinions are welcome. Private messages are just that. Private. We do not monitor them.
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"Okay! You draw the straws. I'm-a taking the parachute."
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JerryWise
Postmaster
Reged: 12/26/03
Posts: 7834
Loc: Lexington, SC
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Quote:
... Stick to stating fact and offering sound opinion. If and when someone disagrees, let them. ...
and then ask them to validate their stance. There are some wonderful lengthy dialogs here on glass type, design and performance all supported by references and side by side evaluations with caveats about sample size and individual equipment differences.
Occasionally, very competent folks leave CN that have little tolerance for inane comments as seen in this and other threads by those wanting to play rather than learn. Also, some experts have moved into the commercial realm and withdrew from their active posting levels because of obvious potential conflicts of interest.
Also, as competence grows there is a natural tendency to acquire exactly what you consider ideal and no longer need to participate in forums on that topic. As an example, I was a prolific poster in mounts looking for the ultimate mount for my needs. The experience of others was put to good use and eventually I worked up to a mount that does everything I could ask. Having that hurdle under my belt, I no longer visit the mounts forum except on rare occasions. I'm not competent to comment on a Celestron CGE Pro or ME-250 since I've never read on them or touched one.
And I think that is a lesson. If you are not conversant on a topic and do not have something valid to contribute or ask then stirring the pot with comments like "your scope s**ks" is not worth addressing. It's a childish attention play and nothing more. Experts will leave if that mentality takes over and from everything I've seen CN will do whatever it takes to prevent that. A glowing endorsement of CNs success is their massive membership, the number of experts that are on the site, the congenial manner of 99.9% of the postings, and the excellent information available for the asking. If that doesn't fit a posters needs then...
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Jerry
Celestron C-11
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AlienRatDog
Pooh-Bah
Reged: 07/15/05
Posts: 1091
Loc: Ann Arbor
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*Sniffle...*Sniffle....can't we all just get a long??? 
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Abe -- the poor PhD student
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12" LX200GPS-SMT w/UHTC
Explore Scientific 127mm Triplet ED APO
Losmandy GM8 EQ mount
Nagler 31mm, 17mm, 13mm, 12mm, 9mm, 2.5x Powermate
12X50 Binoculars
Understanding wife
One beautiful daughter, Emma-Rose (born 7-29-2009)
Twin boys (cats), half Persian/half Alley Cat but all Vermin!
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JoshH
member
Reged: 11/07/08
Posts: 47
Loc: Jefferson City, MO
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I've been able to view quite a bit with a friend's Mewlon 210 and I really enjoy the scope. The contrast is fantastic, and on axis it is very sharp, to me the coma is about the only drawback worthy of serious consideration if price isn't an issue. About the only other scope of similar size and price that can give a better overall view in my opinion would be a Mak-Cass of equal optical quality because of the off axis sharpness. If you live in an area where dew and frost is a serious problem like I do, the lack of dew problems with the Mewlon is a worthwhile trade off. We did have the secondary dew up one night, but on that particular night ground fog would drift past from time to time, but it was only about 6-8 feet high and the viewing at zenith was still quite good. Unless you are very sensitive to coma, want wide field views, or just want huge aperture, I don't think you will be at all disappointed with a Mewlon.
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16" F4.5 Astrosystems Telekit, Galaxy Optics Primary
Meade LX-50 8" F10 SCT Magellen II DSC (For Sale)
Intes Micro MN-56 Maksutov Newtonian
Orion 100mm F6 Achromat
Orion ST-80 F5 Acrhomat
Unistar Alt-Az Mount
Celestron CI-700 Mount
UO 40mm MK-70, 26mm Nagler, 20mm Pentax XW, 13mm Ethos, 8mm Ethos, 4.7mm 5k UWA, TMB Planetary Set, Paracorr.
Modified Canon 400D
Edited by JoshH (10/12/09 10:19 PM)
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Fomalhaut
sage
Reged: 08/16/08
Posts: 243
Loc: Switzerland
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Quote:
I've been able to view quite a bit with a friend's Mewlon 210 and I really enjoy the scope. The contrast is fantastic, and on axis it is very sharp, to me the coma is about the only drawback worthy of serious consideration if price isn't an issue. About the only other scope of similar size and price that can give a better overall view in my opinion would be a Mak-Cass of equal optical quality because of the off axis sharpness. If you live in an area where dew and frost is a serious problem like I do, the lack of dew problems with the Mewlon is a worthwhile trade off. We did have the secondary dew up one night, but on that particular night ground fog would drift past from time to time, but it was only about 6-8 feet high and the viewing at zenith was still quite good. Unless you are very sensitive to coma, want wide field views, or just want huge aperture, I don't think you will be at all disappointed with a Mewlon.
For DSO, I am using my Mewlon-180 mainly with a Pan-22 (98x) which is perfect for globulars and nebular objects such as M27 (Dumbbell). Within this limited real FOV of 0.6 deg there is no coma visible to the edge of the field.
Chris
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Currently:
Tak FS-60c (guidescope for:)
Tak FCT-100/640 on Tak EM-10
Tak Mewlon-180 on same
IntesMicro-M500
Zeiss 7X42-T*P-Dialyt + Nikon 18x70 Binoculars
Coronado Maxscope 40
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4116
Loc: Ireland
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Quote:
... About the only other scope of similar size and price that can give a better overall view in my opinion would be a Mak-Cass of equal optical quality because of the off axis sharpness. If you live in an area where dew and frost is a serious problem like I do, the lack of dew problems with the Mewlon is a worthwhile trade off. ...
That about sums up my take on it as well. I use a Mak-Cass in the observatory where I have ready power for dew control (and don't care about the 100 lbs it weighs), but I use a Mewlon as my portable rig.
Of course a Dob would also be a good portable scope, but it's much easier to sketch from the back of a refractor or Cassegrain.
Cheers,
-- Jeff.
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Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
APM MC1610 / Tak FC-100 / AP1200GTO Tak Mewlon 250 / AP600EGTO
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chuckscap
sage
Reged: 07/18/09
Posts: 220
Loc: Colorado Springs, CO USA
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I'm also hopeful that Tak will eventually listen to the clamoring for a Mewlon visual corrector/flattener but not reducer(essentially making the Mewlon a CDK). There are folks on the Mewlon groups constructing their own from lenses .... But with FOVs of .5 degrees or less in my Mewlon 250 the views are nothing short of stunning and I'm comparing them to a very good C11 and a spectacular C14.
Regards,
Chuck
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pmesquita
sage
Reged: 04/04/09
Posts: 428
Loc: Lisbon, Portugal
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All this fighting...thank God I don't like Cats. Maks or Schmidts...I'm happy just to be a simple Dob guy...:)
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A clear soul is the only thing better than a clear sky - Paulo Mesquita
"Jaws" - XX12 Orion Intelliscope Truss Dob
SW Pro 180mm Maksutov + Giro Mount
31mm T5 Nagler - 22mm T4 Nagler - 13mm Ethos - 7mm Pentax XW
TV Paracorr
2" 1.6 Antares Barlow
2" Astronomik OIII - 2" NPB UHC - 2" Lumicon H-Beta - 2" Baader Moon&SkyGlow
Rigel Red Dot Finder
- 1.25/2" Glatter with Blug
10x50 Bak 4 Binocs
Asus eeePC 1000HE
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chuckscap
sage
Reged: 07/18/09
Posts: 220
Loc: Colorado Springs, CO USA
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A quick update on my Mewlon 250. After talking with Fred at TNR, I took up my trusty 2.5mm T-handle allen wrench and began collimation. I've collimated my C11 and Intes 500 before, but it's never something I'm looking forward to, in particular with an OTA the cost of a Mewlon 250.
Bottom line, I'm about half way through step two (about 300x) of Legualt's collimation procedure, so I'm still a long way from the final step 3 "critical collimation", but even being this close (or far away) views have improved tremendously.
http://www.astrosurf.com/legault/collim.html
The diffraction spikes on brighter stars are razor sharp, I can see very little if any coma on stars at the edge of a 35mm Pan. I collimated on Friday and observed for several hours Saturday (last night). The contrast, resoluton and black background against a light polluted suburban sky was just wonderful(I live on the west side of Colorado Springs and my deck faces East ugh). The views were definitely superior to my very good C11 that I had gotten through step 3 and had achieved critical collimation.
In my mind, we hear of some Mewlon owners who complain of some coma, others who see almost none. I'm guessing some observers are more critical, but others don't have their Mewlons collimated well enough.
Anyway I'm in the Mewlon love column ...
Chuck
Edited by chuckscap (11/08/09 11:36 AM)
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Tony Bonanno
member
Reged: 04/03/07
Posts: 29
Loc: Santa Fe, New Mexico
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I've had a Mewlon 210 for about a year and am generally quite pleased with the views. I put a feathertouch focuser on it and that minimizes having to deal with image shift. I only use the scope for visual. When seeing is good, the Mewlon is very good.
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Mewlon 210
Vixen VMC-260L
Intes MN61 Mak-Newt
CGE
Atlas
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chuckscap
sage
Reged: 07/18/09
Posts: 220
Loc: Colorado Springs, CO USA
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Hi Tony, the Mewlon 250 doesn't move the primary (it has an electric focuser on the secondary). I do miss the Feathertouch Crayford I put on my old C14. I may get one yet for the Mewlon.
Clear skies
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Tony Bonanno
member
Reged: 04/03/07
Posts: 29
Loc: Santa Fe, New Mexico
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Hi Chuck,
If you ever decide you want to part with your 250, let me know.. I could drive up there without much difficulty :-).
Cheers,
Tony
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Mewlon 210
Vixen VMC-260L
Intes MN61 Mak-Newt
CGE
Atlas
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chuckscap
sage
Reged: 07/18/09
Posts: 220
Loc: Colorado Springs, CO USA
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Thanks Tony, I paid $3800 including a BT dovetail plate, so I think it's a keeper for a while. It does have one little dent on top from one of the previous owners (maybe that's why it was out of collimation)
Maybe see you at RMSS?
Chuck
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