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jmoore
Carpal Tunnel
Reged: 10/01/03
Posts: 1959
Loc: Beaufort, NC
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I'm thinkin' about a 5" Mak. Wasn't gonna do this for awhile yet, but I'm gripped by the fever, and I can get a good deal. However, I don't know too much about Maks, aside from all I've read. So, a few questions:
1. Do Maks require collimation? And if so, how easy/hard is it to do compared to a Newt? Are there different tools required?
2. How would a 5" Mak (e.g., Orion Starmax/SVP) compare to a 5" SCT (e.g., Celestron C5-S)? I like the Celestron's shorter focal length (wider field), but I like the Orion's price, and I've heard Maks give sharper images than SCTs. The Mak setup I'd get is also lighter (37 lb) than the Celestron setup (48 lb).
3. How well-suited are Maks for astrophotography...both planetary and DSOs?
4. For planets, I like high mag. How much can I get with the 5" Mak? I know that with the 50x/inch rule, I can get 250x, but this rule is only so helpful. I can get about 65x/inch with my 80mm refractor (about 200-210x), and of course with my 8" Newt, I can never get 400x because of atmospheric limitations. So, I guess I'm wondering whether magnification in a 5" Mak tends to be more optics or atmosphere limited. If atmosphere allows, can the Mak push 275-300x, or do images always break down after 250x in this scope?
5. How much of an advantage will a 5" Mak give me over my 80mm refractor? Will the extra light gathering be significantly noticeable for faint objects? Will the extra planetary mag be significant? (e.g., I can go 200x with the 80mm, so if can only routinely get 220x or so with the Mak, I wouldn't really be gaining much here).
6. Finally, any personal feedback about your experiences with Orion's 127 Maks would be appreciated.
thanks for your help.
jeff
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Hardin 12"
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Anonymous
Unregistered
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jmoore,
ive owned 2 Maks and will try to answer your Qs. Firstly they dont require collimation usually. Also most of them have a high fl my 7" Mak is f15 which makes them outstanding Lunar & Planetary scopes but BAD DSO scopes thats why I also have a C8 its my DSO scope and a must have.
Maks also have a smaller secondary giving better images than a Schmidt of same size, usually. The 5" models are nice I just wanted as big as poss period for planetary you cant beat aperture regardless of scope make. You would have a lot of advantage aperture wise over the 80mm with a 5" BUT again the high fl of the Mak wont allow you wide views of DSOs where the extra grasp is really needed so the 80mm Orion beats it on DSO viewing except when you want to zoom in on something on say Orions central stars etc....then the Mak is the winner.As far as total highest mag goes well......the seeing has 75% to do with what you can push to no matter what scope you own, Ive used a 4.8mm Nagler on Mars on my 7" Mak 2 times last yr. and it was as clear as one could ask BUT the seeing was almost perfect, dead calm and no star twinkling. That was a total of 2 nites out of 365............usually a 15-10mm is as low as I can go.....so about 200-300 total mag on my 7" on a 5" id say to be safe 150-250 maybe except on those unusual nite. Your location has a lot to do with it too. Image wise a 5" is a 5" is a 5" on the Maks until you enter say a Questar quality Mak with more precision figured optics but then the $$$$ goes up BIG TIME tho the quality of the object maybe looks 10% better maybe? So thats strickly a deep pockets decision and not one for the casual observer as the seeing really dosent even permit its full capabilitys very often something that goes hand in hand with seeing again. CCD photography has a good ability to cut thru some bad seeing but the human eye well, dosent.Id own a Mak over a Newt anytime just a lot more convenient to setup and use a Mak verses something that requires more space and some standing to use. Hope ive helped, Dave
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litespeed
scholastic sledgehammer
Reged: 10/31/03
Posts: 948
Loc: Sebastian, FL
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Jeff,
I have the Orion Skyview Pro 127. Mine has never needed collimating. Still in perfect collimation too. It has rolled of car seats. Been on aircraft, etc... No problems at all!!
You can really crank it up on still nights. I spend most of my time over 308x with mine. On still nights I crank it up to 462 and it can easily take much more!
Imaging with the Toucam Pro with the the Ultima 2x is F/24. Cheating with the barlow ahead of the diagonal runs it up to over F/36 and the images are still clear. I wish I had a 5x powermate sometimes, even though I should not be using that kind of mag.
It does take a long time to cool down in winter. Some nights it never does.
Great little scope... Hope this helps...
AJ
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AJ
Orion 127 SVP
TouCam
Canon 20D
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jmoore
Carpal Tunnel
Reged: 10/01/03
Posts: 1959
Loc: Beaufort, NC
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thanks very much for the feedback. Yes, I'm aware that with the long focal length, you're giving up FOV. I wouldn't plan to use the Mak on M45 or anything, but I imagine the FOV is not limiting when you're talking globulars or small nebula (dumbell, ring, etc.). Presumably then, the 5" will definitely help over the 80mm.
AJ, sounds like you've got some pretty good seeing conditions there! It's not bad where I am either (northern IN...midwestman can relate!). I've been looking at Saturn at 208x just about every time this winter in my 80mm. So, seeing hasn't been too limiting lately. I was at 275x the other night with my 8" Newt. So from what you're both saying, I think 250x - 300x might be commonly reachable for me with a 5" Mak. Good to know.
cheers,
jeff
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Hardin 12"
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Tom L
Reged: 01/07/04
Posts: 29811
Loc: Sunny Oregon
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I bet a 5" Mak would be great on planetary nebula and doubles as well. You're not going to get rid of the 8" reflector, so there is a fine widefield DSO hunter along with a nice 80 and Mak. Not to bad of a setup! You could share the mount with the Mak and reflector if it is big enough.
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Tom 
Tele Vue 102mm f/8.6 on an EzTouch
Vixen 80mm f/5 A80SSWT on a grab-n-go mount
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jmoore
Carpal Tunnel
Reged: 10/01/03
Posts: 1959
Loc: Beaufort, NC
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That's what I'm thinking, Tom. 8" reflector, 5" Mak, 80mm refractor. DSOs, planets, wide-fields, grab-n-gos. I'm set.
I'd probably try to have 2 mounts to accomodate the 3 scopes. The 8" reflector's mount could obviously handle the Mak. I want my smaller mount to be sturdy enough for the Mak, too. That way, I could simultaneously set up the 8" reflector and the Mak if I wanted to. And then either mount would be VERY sturdy for the 80mm (for astrophotos or whatever). I think an EQ-3 would be sturdy enough for the Mak, and still light enough to consider grab n go with the 80mm.
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Hardin 12"
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Victor Kennedy
Pooh-Bear
Reged: 05/22/03
Posts: 9794
Loc: Slovenia
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I'vve no experience with the Orion Starmax 127, but I did have a direct comparison with a friend's Meade 105 mm MCT and my AT1010. The Meade showed much more detail in the Orion nebula. The f.o.v. wasn't as wide (but you know that already). What surprised me was the pin-point stars in the Meade. I had read about "blobby" stars in CATs, but the view of the stars in the Meade disproved that. They were much smaller than the stars in my C8, which I bought later.
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To err is human; to moo is bovine.
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Spyke
Carpal Tunnel
Reged: 07/22/03
Posts: 1916
Loc: Scotland
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Hi,
I've owned and loved my 5" Synta Skymax Mak (same as Orion 127) for about 18 months now, and have found it to be great.
The field of view is narrow, but bear in mind that with a 40mm eyepiece you can have a view thats 37x and about a degree and a quarter (TV 40mm plossl figures) that will be very very sharp and colour free! Ok, so it's not wide field, but it's not a drinking straw either.
It does take at least an hour and a half to cool down when there's a big temperature difference. I usually start off by using the 4" refractor till it's cool (leave it open and exposed to cooler air) and then switch tubes onto the EQ3. And speaking of mounts....the EQ3 (Synta Skyscan 2001) is fine for it. Helps if you add some washers wherever you see a gap, and regrease the internals, but it can carry the load fine.
Target-wise it excells on planets and moon, planetary nebula, double stars...no surprises really. I find my best views to be in the 180x to 220x range, but that is limited by seeing, in my experience.
Mine has needed to be collimated once, which is not bad in 18 months, although it could do with a tweak just now too. It's done with small allan keys (two sizes needed on my model) and is basically an adjustment of several groupings of push/pull adjusters. I don't like doing it, but it's not difficult.
I like 'em, but then, I'm biased!
Ant
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GSO 8" f6 Dob (Hi-Lux coated)
ED100 Pro, ED80
Skymax 127 Maksutov
Coronado Ha PST
Vixen GP, Porta-mount, multiple AZ-3 mounts.
Berkut 10x50 Binos, 'reasonable' no. of eyepieces
Should I buy an Equinox 120ED? 
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Anonymous
Unregistered
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I had an Orion Apex 127 OTA that I sold when I bought my Vixen. Very sharp, well-collimated. Gave good, high magnification views (350x or better) when seeing permitted. It will have about double the light gathering ability of the 80mm scope you have now, so will be better for some DSOs. It's very good on the brighter DSOs like the planetary nebulae and okay on globulars. Still not really enough aperture to resolve globs, though. MCTs show stars as smaller points than SCTs. Resolution will be slightly inferior to a 100mm refractor, maybe more like a 90mm, and contrast will be a bit lower than a refractor since the tube isn't baffled like a refractor's can be. Otherwise, a very good scope if you don't mind giving up 2" eyepieces and wide-field views. But , hey, you'll never need a barlow with the thing either!
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12494
Loc: Cumberland, R I , USA42N71.4W
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Several days ago we had a similar discussion, also initiated by jeff, over in the planetary observing forum. A discussion about equivalent resolution is posted over there.
The short of it is this. Common discussion says for an obstructed scope, subtract the diameter of the obstruction from the total aperture and the result is equivalent aperture for comparing potential resolution to an un-obstructed scope. Empirical testing shows this produces a result far lower than what you really get for resolution. Losses are not that great.
Point source resolution, not so much affected by contrast, will not decrease by that amount. Resolution may be found to be equivalent to full aperture minus only half of the central obstruction diameter.
Extended object resolution, as Warpd points out, is much more dependant on contrast and will be affected more, but still probably not to the extent you need to subtract the full diameter of the central obstruction.
For an obstructed scope with a central obstruction approaching something as small as 20% of full aperture, i.e., a 25mm c.o. in a 125mm scope, there will be almost no discernable affect on either resolution or contrast.
See this discussion
sources of variation in resolution
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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jmoore
Carpal Tunnel
Reged: 10/01/03
Posts: 1959
Loc: Beaufort, NC
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Thanks as always, Ed. Yeah, I was right there with you in the "SOV in resolution" discussion. Made perfect sense...and I was happy to hear your optimistic conclusions.
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Hardin 12"
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