Covey32
professor emeritus
Reged: 12/09/04
Posts: 613
Loc: Georgia
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Why no reviews anywhere about this scope?
Seems strange....Nobody bought any ?
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Hank
12.5" Mag1 Portaball
Orion 120mm F5 Refractor
Skywatcher 120ED F7.5 Refractor
1982 Celestron C8 Orange tube
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ForgottenMObject
Post Laureate
Reged: 09/11/04
Posts: 3581
Loc: Maryland, US
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They are brand new - you probably have to wait a bit to see some reviews.
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Matthew
IDA member
XT8i, 10x50 binoculars, lots of eyepieces
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Clive Gibbons
Mostly Harmless
Reged: 05/26/05
Posts: 9785
Loc: Oort Cloud
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Quote:
Why no reviews anywhere about this scope?
Seems strange....Nobody bought any ?
These are made by Synta and also sold as Sky-Watcher 150mm Maksutovs. A friend of mine owns one and is quite happy with it.
One caveat: The actual aperture of the 150mm is approx. 142mm. This is because the primary mirror is slightly smaller than necessary to deliver a full 150mm clear aperture (entrance pupil) at the corrector lens. The 127mm Mak suffers from the same issue. It's "entrance pupil" aperture is 121mm, as measured by Sky and Telescope magazine in their March 2002 review.
Cheers,
Clive.
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A few telescopes of dubious value.
Understanding wife and three curious cats.
"Semper ubi sub ubi"
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southmike
Carpal Tunnel
Reged: 11/22/04
Posts: 2819
Loc: Fayetteville, NC
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this is the closest review i have seen
Quote:
Well it turned out to be clear tonight so I got the scope out for a test. Jupiter was too low in the sky to view well so I had to go with the double-double in Lyra as my primary test subject. I was able to use Jupiter to check image shift though. At 450x the shift was about 1/2 diameter of the planet. I'm sure someone else can figure out the math behind that and what it really means but for me it was just my observation. The double-double split very nicely at 200x but I could tell that it would be a lot cleaner if I adjusted the collimation. I started that process with some success but by 11pm the mosquitoes were so fierce that I had to pack it in for the night. At this point I find the scope to be very similar to the Orion 127 Mak I had before with the benefit of more aperture. I plan on doing a side by side comparison with my Meade 127ED/APO once the collimation is to my liking and will make a report of my findings.
Greg
just curios do you know the actual view of a nexstar 5?
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group scope pic
my refractors
LX200 10"-St120
LX200 8" f6.3-Orion 80ed
LX200 8" f10-Orion 90 Mak setup pic
Meade 102ED LXD650
Sky Watcher 100 ED Triplet prototype
Nexstar 5
etx125
etx70's
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Starman1
Postmaster
Reged: 06/24/03
Posts: 10837
Loc: Los Angeles
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Another competitor of this new scope is the Celestron C-6 Schmidt-Cassegrain, which has a shorter f/ratio and a wider field of view. Price is similar, but a little less for the Celestron.
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Don Pensack
12.5" Truss Dob, 5" Maksutov
Sustaining Lifetime IDA member, TeleVue junkie
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Kenny
professor emeritus
Reged: 07/04/05
Posts: 537
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Quote:
Why no reviews anywhere about this scope?
Seems strange....Nobody bought any ?
I'm not aware of any full reviews, but there are a few older threads on CN about this scope. As I mentioned in one of these older threads, there is a used Skywatcher version at Kendrick's (used price already reduced!) if anyone is interested.
Ken.
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Greg W
member
Reged: 02/26/05
Posts: 28
Loc: Wales, Maine
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Quote:
this is the closest review i have seen
Quote:
Well it turned out to be clear tonight so I got the scope out for a test. Jupiter was too low in the sky to view well so I had to go with the double-double in Lyra as my primary test subject. I was able to use Jupiter to check image shift though. At 450x the shift was about 1/2 diameter of the planet. I'm sure someone else can figure out the math behind that and what it really means but for me it was just my observation. The double-double split very nicely at 200x but I could tell that it would be a lot cleaner if I adjusted the collimation. I started that process with some success but by 11pm the mosquitoes were so fierce that I had to pack it in for the night. At this point I find the scope to be very similar to the Orion 127 Mak I had before with the benefit of more aperture. I plan on doing a side by side comparison with my Meade 127ED/APO once the collimation is to my liking and will make a report of my findings.
Greg
Follow up to my initial posting. The scope did not compare well to the Meade 127ED. The 150 Mak had a brighter image but was no where near as sharp as the 127ED. I tested the 2 scopes on Jupiter, Mars and several stars/doubles. The 150 Mak also had something I had never seen in any scope before. As a bright object such as Jupiter was coming into the field of view there was a large loop of light that filled the view and gradually went away as the object moved towards the center of view. Although my mount tracks and I do not need to worry about anything moving across the field of view, I felt it would certainly be bothersome to someone without tracking. I was able to collimate the scope very easily but it just never reached the level of quality I had hoped for. I sent the scope back.
Greg
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Ken603a
sage
Reged: 05/06/05
Posts: 445
Loc: Texas, USA
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My Mak 102 has this loop of light on the very edge as the object moves into the view, but as soon as the full object is viewable it fades away. It hasnt stopped me from enjoying the Mak. Perhaps this is a general MAK issue?
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Happy Skies!
10 X 50 binoculars
Orion MAK 102 EQ with 6X30 RACI finder and home built zero finder.
10" X-Class DOB 9 X 50 RACI finder.
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Greg W
member
Reged: 02/26/05
Posts: 28
Loc: Wales, Maine
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Quote:
My Mak 102 has this loop of light on the very edge as the object moves into the view, but as soon as the full object is viewable it fades away. It hasnt stopped me from enjoying the Mak. Perhaps this is a general MAK issue?
That is a possibility but I never had this with the 127 Mak I owned previously. For $650 I think the scope is still a good deal, but I was hoping for something to replace the large set up I have now. I guess I will just keep what I have now even though it is a little bulky.
Greg
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mooreorless
Carpal Tunnel
Reged: 07/05/05
Posts: 1512
Loc: Cornpropst Mills,Huntingdon,Pa
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Hello Fellows,I'm no expert but on Amart a fellow had trouble with halo of light around planets etc. with an Orion 102 Mak and they told him to stop down aperture with 1/4 inch to 1/2 inch mask to test for turned edge.Something to try.But then if you are happy with the Mak why bother.Cheers.
Steve M
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Regards,Steve M
"the eights are better" Jim Carmichel of Outdoor Life magazine
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Ken603a
sage
Reged: 05/06/05
Posts: 445
Loc: Texas, USA
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Turned edge? Sounds like something that needs to be fixed by a manufacturer... Mine doesnt seem as bad as Greg's problem, but I would like to have the scope in the condition it is intended to be in. I may call Orion and see what they say...
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Happy Skies!
10 X 50 binoculars
Orion MAK 102 EQ with 6X30 RACI finder and home built zero finder.
10" X-Class DOB 9 X 50 RACI finder.
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Larry F
Pooh-Bah
Reged: 05/24/04
Posts: 1330
Loc: Westchester, NY
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Inadequate length of dew shield, permitting reflections of bright objects from the corrector plate even though they are off axis?
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C5 Orange Tube SCT
Orion 127 Mak
SV Nighthawk (1st generation)
CPC 800 XLT SCT
Coronado Maxscope 40
Denk II Binos
Giro 2/Tech2000 Giro Driver/Tech2000 QuickDraw Pier
A zillion eyepieces and some more mounts
Mason & Hamlin BB 214 cm (piano)
My Gallery
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Starman1
Postmaster
Reged: 06/24/03
Posts: 10837
Loc: Los Angeles
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Quote:
Hello Fellows,I'm no expert but on Amart a fellow had trouble with halo of light around planets etc. with an Orion 102 Mak and they told him to stop down aperture with 1/4 inch to 1/2 inch mask to test for turned edge.Something to try.But then if you are happy with the Mak why bother.Cheers.
Steve M
The mirrors on Orion's Maks are undersized, i.e. the light that passes through the edges of the corrector lens misses the edge of the mirror. A 1/2" wide annulus around the front of the corrector would only eliminate the very edge of the primary mirror (if it is the cause).
I've thought about it, and I think two things may be happening:
1) the light bent outward by the outer edge of the corrector may be reflecting from the side of the tube into the light path. This would be more severe the farther off-axis the image was, which seems to be the case.
2) There is inadequate front-end baffling of lateral light coming into the scope.
#1 could be solved (with some difficulty) by flocking the inside of the tube and outside of the primary baffle.
#2 could be solved with a dewshield of 6" length that is very unreflective internally.
Alternatively, the corrector might be filthy and scattering light. The eyepiece may be dirty and doing the same.
But I'd bet on light scatter in the tube, simply because I saw such a huge difference when I flocked my SCT, which doesn't cause the entering light to diverge as much as a Mak.
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Don Pensack
12.5" Truss Dob, 5" Maksutov
Sustaining Lifetime IDA member, TeleVue junkie
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mooreorless
Carpal Tunnel
Reged: 07/05/05
Posts: 1512
Loc: Cornpropst Mills,Huntingdon,Pa
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Hi Larry and Don,I am lucky I have a dark site here and am not bothered with stray light.I have to remember to think of the easy fixes,but then these fellows should already have dewshields.
Steve M
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Regards,Steve M
"the eights are better" Jim Carmichel of Outdoor Life magazine
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DIO
super member
Reged: 11/12/04
Posts: 101
Loc: KY, USA
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Guys, I have already mentioned and solved this problem. I have an Orion 90mm Apex.
Master Pensack  has caught the root cause: The bright loop of light is eliminated if you put flocking paper in the inside of the tube - the small tube which goes through the primary mirror. It appears that this problem is very frequent in the Orion Maks. Nothing to do with the optics.
For those interested in the history of this, look under my name in a previous CAT thread - sorry I cannot post the link right now, but I don't have many entries at CN anyway, so it's easy.
Cheers,
Dimitri
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DIO
super member
Reged: 11/12/04
Posts: 101
Loc: KY, USA
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By the way, before that, I tried:
- Dewshield: No good.
- Flocking primary tube: No good.
- Masking the external ~0.5 inch (the stopping solution discussed above): No good.
- Masking/covering/flocking the shiny metallic parts which hold the corrector lens in place: No good.
So, effectively I took the scope apart and put it back together about a dozen times until the problem was identified and solved. And it was with the help of another CNer, who suggested a specific test.
Cheers again,
Dimitri
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stevie
Spiderman
Reged: 12/07/03
Posts: 3135
Loc: Belgium
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you can read more about it here
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stephane
Our shots(updated :18.02.2008)
My videos
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mooreorless
Carpal Tunnel
Reged: 07/05/05
Posts: 1512
Loc: Cornpropst Mills,Huntingdon,Pa
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Hi Dimitri,This is wild some of the things that you can do to fix scopes.I told the guy on Amart about this and he is going to try to do it but is worried to take his scope apart.Clear Skies.
Steve M
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Regards,Steve M
"the eights are better" Jim Carmichel of Outdoor Life magazine
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DIO
super member
Reged: 11/12/04
Posts: 101
Loc: KY, USA
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Clear skies to you too Steve! And good to hear from you again Stephane! Thanks for posting the link. All, it was Stephane's test which helped solve the problem!
Dimitri
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Starman1
Postmaster
Reged: 06/24/03
Posts: 10837
Loc: Los Angeles
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Steve,
This mod can be done without taking the scope apart.
Roll up the flocking paper(don't remove the backing--you're not gluing it in yet) into a tube slightly smaller than the inside diameter of the primary mirror's baffle.
When you insert it in the back, it will unroll until it fits the inside of the baffle tube fairly snugly.
Make certain it is not long enough to stick out the front of the baffle tube.
Star test the scope. Eliminate the problem? (Sounds like it might be yes).
Remove the rolled-up flocking paper and be certain it is exactly the length/width to go around the inside of the baffle WITHOUT OVERLAP. Remove the backing, and roll the tube until it just barely overlaps. Insert the tube into the baffle(try very hard not to hit the sides of the baffle tube when inserting). Insert a piece of wooden or plastic doweling slightly smaller than the I.D. of the baffle tube and roll it around the perimeter of the baffle to press the flocking paper in place.
If this seems to be difficult because you doubt you can stick it in without touching the sides of the baffle, then before you pull the backing paper off the adhesive, cut it into two strips and put one strip in first, then turn the scope over and put in the other strip. Remember: NO OVERLAP. The adhesive sticks very well to metal, but not to the fuzz on the top of the flocking paper itself.
So, no dismantling necessary.
Good luck.
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Don Pensack
12.5" Truss Dob, 5" Maksutov
Sustaining Lifetime IDA member, TeleVue junkie
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