Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Any little Mak fans here?

  • Please log in to reply
167 replies to this topic

#76 Cajundaddy

Cajundaddy

    Surveyor 1

  • *****
  • Posts: 1867
  • Joined: 27 Dec 2016
  • Loc: Cucamonga CA

Posted 21 August 2019 - 03:46 PM

Every scope design has a "sweet spot" for the user and a small MAK is no different.  Small, light weight, low price, long focal length for moon and planets?   I'll grab my C90 and enjoy. 

 

Wide field, lower power, tack sharp, photography? I'll choose the AT72ED. 

 

Under jet black skies?  Aperture rules and I will choose an 8" or larger scope to chase the faint fuzzies that are difficult or featureless with smaller scopes.

 

There are no perfect scopes for every situation and they all represent a compromise in aperture, FOV, portability, or cost to own.  Pick your poison but no self respecting BY astronomer should allow themselves to be limited to only one. 


  • Sarkikos, pdxmoon, Joe1950 and 1 other like this

#77 Joe1950

Joe1950

    Cosmos

  • *****
  • Posts: 9596
  • Joined: 22 Aug 2015

Posted 21 August 2019 - 03:52 PM

That’s understandable, Frank. But one night, I made a really bonehead blunder.

 

I was observing the moon at first quarter or so. There had been a thread about which eye you use to observe that day. So just for kicks, I switched from my normal right eye to my left.

 

I was floored! The moon was so much brighter in my left eye! Had I burned out my right eye with so much observing?

 

Then it finally came to me. While looking with my right eye at a bright object, the iris had closed as is normal. My left eye was closed all that time and the iris probably opened to the max size. So making the switch, all that light went into my left eye unimpeded!

 

Don’t tell anyone. I felt very foolish as it was.  crazy.gif


Edited by Joe1950, 21 August 2019 - 04:53 PM.

  • pdxmoon and fcathell like this

#78 highfnum

highfnum

    Aurora

  • *****
  • Posts: 4574
  • Joined: 06 Sep 2006
  • Loc: NE USA

Posted 21 August 2019 - 04:38 PM

Well a while back My etx90 Mak-cass

married my astele 60  mak-greg

and had a little one 30mm lomo mak-greg

(took after mom)wink.gif

 

maks.jpg

 

 


  • ArizonaScott, Sarkikos, Boom and 4 others like this

#79 Boom

Boom

    Messenger

  • *****
  • Posts: 436
  • Joined: 11 Jan 2008

Posted 21 August 2019 - 05:18 PM

Well a while back My etx90 Mak-cass

married my astele 60  mak-greg

and had a little one 30mm lomo mak-greg

(took after mom)wink.gif

 

attachicon.gif maks.jpg

 

Well, I posted a photo of some little Mak's meniscus correctors on the first page, but I didn't include this angle which shows the OTAs.

 

Now seems like a good time, since you brought it back up. lol.gif

 

Maks2.jpg


  • ArizonaScott, highfnum, Sarkikos and 4 others like this

#80 fcathell

fcathell

    Apollo

  • *****
  • Posts: 1163
  • Joined: 30 Jul 2017
  • Loc: Tucson, AZ

Posted 21 August 2019 - 05:32 PM

Joe - I did/noticed the same thing years ago.  I observe with my left eye and when I switched to my right eye the brightness floored me! I think we have all done this one time or another. 

 

Frank


  • Joe1950 likes this

#81 fcathell

fcathell

    Apollo

  • *****
  • Posts: 1163
  • Joined: 30 Jul 2017
  • Loc: Tucson, AZ

Posted 21 August 2019 - 05:35 PM

Boom - the secondary obstruction on that 1" dia Mak look enormous w.r.t. the aperture. Looks to be about 70%!  What is the F-ratio of this little baby Mak?

 

Frank


  • Joe1950 likes this

#82 Boom

Boom

    Messenger

  • *****
  • Posts: 436
  • Joined: 11 Jan 2008

Posted 21 August 2019 - 05:44 PM

Boom - the secondary obstruction on that 1" dia Mak look enormous w.r.t. the aperture. Looks to be about 70%!  What is the F-ratio of this little baby Mak?

 

Frank

 

Frank, 

 

Supposedly around f/5.1 ; D=30mm, F=152mm.  It's marketed as a 10x30 monocular.  More of a novelty than anything.


  • alvin58 and Joe1950 like this

#83 Joe1950

Joe1950

    Cosmos

  • *****
  • Posts: 9596
  • Joined: 22 Aug 2015

Posted 21 August 2019 - 06:59 PM

Just some historical perspective.

 

The Maksutov design was invented by a Russian optical engineer and amateur astronomer, Dmitry Dmitrievich Maksutov.

 

His first prototype was finished in 1942. It was 100mm in diameter and about f/8.5 if I recall.

 

This first scope was based on the Gregorian-Cassegrain design (not to be confused with a Gregory Maksutov). As such, the secondary mirror/spot on the corrector lens was concave, not convex. The meniscus corrector lens was therefor placed beyond the primary focal point and the corrector lens bulged outward rather than the familiar inward curve of the contemporary ‘Gregory Maksutov’ sold today.

 

The reason Maksutov designed it this was to give upright images from the scope, making it useful for terrestrial as well as astronomical viewing.

 

It is said that ideally, a Gregory Maksutov is designed with some degree of under-correction. This is done to compensate for higher order aberrations introduced by the steeply curved glass surfaces. This has been noted in an essay by the famous lens designer and maker, Roland Christian, who notes similar design issues with triplet APO lenses. 

 

His message being that under such circumstances, residual spherical aberration seen in a star test is desirable in order to attain the best in-focus star image. This supports the idea that the star test, while considered the tell-all test for telescope performance, is not always so for some optical designs. 


  • Sarkikos, Boom, fcathell and 1 other like this

#84 highfnum

highfnum

    Aurora

  • *****
  • Posts: 4574
  • Joined: 06 Sep 2006
  • Loc: NE USA

Posted 21 August 2019 - 07:14 PM

I think little lomo works pretty well

I find it a bit crazy that you would engineer such a design so small

it seems like overkill 

it even came with signed spec sheet!


Edited by highfnum, 21 August 2019 - 07:16 PM.


#85 Cali

Cali

    Viking 1

  • *****
  • Posts: 976
  • Joined: 21 Aug 2018
  • Loc: Bay Area

Posted 21 August 2019 - 09:13 PM

127mm with a Binoviewer which has made all the difference.

 

- Cal

Attached Thumbnails

  • Cat_Bin_2.JPG

Edited by Cali, 21 August 2019 - 09:14 PM.

  • elwaine, Joe1950, Shorty Barlow and 1 other like this

#86 Bill Barlow

Bill Barlow

    Skylab

  • *****
  • Posts: 4383
  • Joined: 03 Dec 2007
  • Loc: Overland Park KS

Posted 22 August 2019 - 09:39 AM

I think it may be an optical illusion caused by FOV and magnification.

 

Two nights ago I compared the views of an SW102 4" refractor with my new c127MAK. The refractor appeared "brighter". I was mystified by this. I checked to see if it was because I had a lunar filter on the MAK. It wasn't. 

 

I think what was going on was the difference in magnification. There was very little black sky in my MAK ep, and it was more magnified a view with the same ep than the refractor. When I lowered the magnification of the MAK, the "brightness" I was seeing in the refractor was also in the MAK.  Also, there was more black sky around the white moon when I lowered the magnification, and in the refractor, which is faster, it was always framed against more black sky with the same ep.

 

Does that make sense? Because at 127, even with an obstruction and all the rest, the MAK has to gather more light than the 4". So, what I perceived was certainly an optical illusion.

 

Contrast and sharpness in the MAK were excellent, BTW.

When I did the side by side with the Tak FC76 and Intes M500 I used similar magnifications.  I had a 7mm  XW in the MAK for 181X and a 3.5mm XW and a Siebert 2.9mm Starsplitter in the Tak for 163X and 197X respectfully.  This translates to exit pupils of .7mm in the MAK and .47mm and .38mm in the Tak.  The images were brighter in the Tak even with smaller exit pupils and 2” less aperture so it must be poor reflective coatings in the M500. 

 

Bill


  • Boom and pdxmoon like this

#87 Bowlerhat

Bowlerhat

    Ranger 4

  • -----
  • Posts: 335
  • Joined: 05 Jun 2019
  • Loc: Melbourne, Australia

Posted 22 August 2019 - 04:18 PM

I had one, briefly. 80mm/f1000mm mak from skywatcher. It comes from a bundle called 80AZ Gte, paired with the computerized mount AZ GTe. Sold it because I need an AZ GTi, but still regretting it because it's a rather uncommon scope.
 
1 (2)

 

Weird scope, really light, much longer than the 90mm skymax. The focuser is rubbery, the view is much dimmer than my C5 but sharp. The extended 1.25" eyepiece tube has a compression ring clamp (really nice in my opinion) and it only comes with a finder shoe for a red dot. The extended part is part of the scope and cannot be unscrewed. I rather like too on how it comes with a side saddle arrangement which is quite nifty. Small write up here

 

I need to get a 90mm cat..


Edited by Bowlerhat, 23 August 2019 - 03:28 PM.

  • ArizonaScott, Boom and treadmarks like this

#88 Shorty Barlow

Shorty Barlow

    Viking 1

  • -----
  • Posts: 825
  • Joined: 15 Sep 2015
  • Loc: Lloegyr

Posted 23 August 2019 - 08:51 AM

127mm with a Binoviewer which has made all the difference.

 

- Cal

127mm Mak's are virtually made for BV's IMO.

 

gallery_249298_10580_37046.jpg

 

127mm Sky-Watcher SkyMax/AZ5 bundle with WO bino's.


  • elwaine, Boom, pdxmoon and 3 others like this

#89 Jeff Lee

Jeff Lee

    Surveyor 1

  • *****
  • Posts: 1636
  • Joined: 17 Sep 2006

Posted 23 August 2019 - 09:16 AM

A very long time ago when I thought I wanted to get into astronomy but also had/have a strong interest in terrestrial life I got one of the USA made Rubber Coated C90's with the special coatings and the nice travel hard case. Its been to Mexico, Costa Rica , and many places in Oregon. I kept telling "Uncle Rod" that he needed to re-evaluate the C90. Interesting read on when and how he got his. Then his conclusion was, "as good as the ETX". Now that I have a few Astro miles under my belt I know I got a good one. I have two kits but by far my most used kit is the SLT/ST80 (just order a yellow #8 for it)/C90. I use both kits for EAA. When the C90 is cooled (I think a lot of the poor reports about the USA made one came from the uncoated ones which had not been cooled). I even have a 2"  2 speed focuser I use (sometimes) (actually both the C90 and ST80 have 2" focusers). From spotting lizards to DSO (either dark Oregon skies or EAA at home) the C90 since 1996 has never failed me. I did take it apart and re-grease it. One heavy little chunk of a scope.

 

My first view with my stepson was of Saturn and that was what a way to begin.


  • ArizonaScott and Joe1950 like this

#90 Bowlerhat

Bowlerhat

    Ranger 4

  • -----
  • Posts: 335
  • Joined: 05 Jun 2019
  • Loc: Melbourne, Australia

Posted 23 August 2019 - 03:29 PM

Can't go wrong with a small refractor and a mak on a photo tripod. One for deep sky, one for planetary.

 

Here's the 80mm propped up on slik photo tripod.

1 (4)

 

I even read that member jrbarnett dropped it (C90) on his driveway and it survived.


Edited by Bowlerhat, 23 August 2019 - 04:46 PM.

  • PXR-5 and Joe1950 like this

#91 Jim1804

Jim1804

    Ranger 4

  • -----
  • Posts: 323
  • Joined: 26 May 2011
  • Loc: Raleigh-Durham NC, USA

Posted 23 August 2019 - 03:41 PM

If this thread has inspired anyone, someone posted over on the BIG C90 thread that Optics Planet has the C90 bundle for just over $150. The tripod is junk, but you get two Plossls and the OTA for the best price I’ve seen in a while...
  • pdxmoon and Joe1950 like this

#92 Cali

Cali

    Viking 1

  • *****
  • Posts: 976
  • Joined: 21 Aug 2018
  • Loc: Bay Area

Posted 23 August 2019 - 04:57 PM

127mm Mak's are virtually made for BV's IMO.

 

After a moment of quiet reflection I've concluded that you pretty much nailed it Shorty.

 

- Cal


Edited by Cali, 24 August 2019 - 04:51 PM.

  • Joe1950 and Shorty Barlow like this

#93 bbqediguana

bbqediguana

    Viking 1

  • *****
  • Posts: 930
  • Joined: 28 Feb 2015
  • Loc: Canada

Posted 23 August 2019 - 05:13 PM

Hmmmmm... I do love tiny Maks - the look of the meniscus corrector is awesome, and do like their sharpness. However, they generally have a long focal length and throw up dim views compared to a similarly sized refractor. And the short tube refractors aren't all that much longer than the Mak.

 

In the past I've had:

  • Vista MC90 (an f/5.6 Mak)
  • Meade ETX 90/EC
  • Questar 3.5 Standard
  • Orion StarMax 127
  • Celestron C65

Those have all left my possession, and currently my g&g/travel scope is a 70mm f/7.1 refractor.

 

I do love Maks, but honestly I love the performance of refractors more. They are brighter, usually as sharp or sharper and can do wide field which a Mak really cannot do. A Mak will likely do higher power more easily than my 70mm achro, but I had my 70mm up to 133x on Jupiter and Saturn the other night and it was doing just fine. If I were to upgrade to a small ED or APO, I think the Mak wouldn't have an advantage there either.

 

So, the long and the short of it is although I do personally love Maks, refractors to me simply work better.

 

Ick. I never thought I'd say that!

 

Cheers!

 

Rick


  • Boom and Joe1950 like this

#94 Joe1950

Joe1950

    Cosmos

  • *****
  • Posts: 9596
  • Joined: 22 Aug 2015

Posted 23 August 2019 - 05:30 PM

127mm Mak's are virtually made for BV's IMO.

 

gallery_249298_10580_37046.jpg

 

127mm Sky-Watcher SkyMax/AZ5 bundle with WO bino's.

Believe it or not, I decided to try my binoviewer in my ETX-90 OTA, mounted on a Celestron Alt-Az (with slo-mo). The common saying with 90mm Maks is that they run out of light before they run out of detail.

 

So you would say such a scope with a binoviewer which splits the light in half would just not work. Add to that, the target, Jupiter was maybe 15o off the horizon and the conditions were typical NJ summer; hazy, hot and humid.

 

But I gave it a go anyway. To make things even harder, I used 16mm eyepieces with a 2x nosepiece/Barlow, giving 155x.

 

Well. The disk of Jove was a fairly good size in the binos. The edge was sharp, and it was not at all lacking for light! It wasn’t blindingly bright, but much brighter than I’d ever expect.

 

“Okay, joe1950, we’ll buy that fish story. But for sure with the planet so low in the NJ weeds with the soupy summer haze, and using a small older Mak with a largish secondary obstruction, you’re not going to expect us to believe you actually had any contrast to see any hint of the belts?”

 

The contrast between the very dark belts and the lighter areas was the most surprising thing of all! I was floored at how the NEB and SEB stood out, with edge variations visible. The poles had a slightly different cast from the rest of the disk, and I could just make out a hint of the whitish sub-belt that has been part of and to the south of the SEB; it runs directly into the GRS that was (confirmed by my Jupiter app) on the far side.

 

Last year I recall using this ETX-90 on Jupiter and being disappointed at how dim it appeared.

 

But this observation with the binoviewer was a complete 180! I personally question what some observers report that seems impossible or improbable. So I’m not into exaggeration or wishful seeing. I report what I definitely see and nothing more. And that’s what I observed.

 

Next clear night I’ll duplicate conditions and verify, if I get the same results.

 

Thanks,

joe


  • Boom, Shorty Barlow, treadmarks and 1 other like this

#95 Joe1950

Joe1950

    Cosmos

  • *****
  • Posts: 9596
  • Joined: 22 Aug 2015

Posted 23 August 2019 - 06:00 PM



Hmmmmm... I do love tiny Maks - the look of the meniscus corrector is awesome, and do like their sharpness. However, they generally have a long focal length and throw up dim views compared to a similarly sized refractor. And the short tube refractors aren't all that much longer than the Mak.

 

In the past I've had:

  • Vista MC90 (an f/5.6 Mak)
  • Meade ETX 90/EC
  • Questar 3.5 Standard
  • Orion StarMax 127
  • Celestron C65

Those have all left my possession, and currently my g&g/travel scope is a 70mm f/7.1 refractor.

 

I do love Maks, but honestly I love the performance of refractors more. They are brighter, usually as sharp or sharper and can do wide field which a Mak really cannot do. A Mak will likely do higher power more easily than my 70mm achro, but I had my 70mm up to 133x on Jupiter and Saturn the other night and it was doing just fine. If I were to upgrade to a small ED or APO, I think the Mak wouldn't have an advantage there either.

 

So, the long and the short of it is although I do personally love Maks, refractors to me simply work better.

 

Ick. I never thought I'd say that!

 

Cheers!

 

Rick

 

I feel the same way, Rick. I have two ED glass refractors and inch for inch, they perform better than other designs. And there is a reason for that. All things being equal, such as diffraction limited quality, seeing and so on, a refractor, being a unobstructed scope (no secondary obstruction) should perform better than the same or similar size Mak.

 

A 30% or more secondary obstruction has significant negative impact on detail and especially contrast!

 

But, the Maks have their advantages. They do not suffer from chromatic aberration. Their long focal length helps moderate eyepieces perform better. The corrector and primary optics are spherical and much easier to mass produce with good quality than are scopes with aspheric elements.

 

And, their size lends itself to a stable, low vibration mounting situation. A long heavy refractor on a moderate size and weight (and cost) mount is prone to a back and forth movement known as a ‘moment arm.’ Focusing such a scope while it’s swaying like that is difficult!

 

On the side of refractors, they cool down much faster than any other design scope. Maks are known to take the longest of all types. Many put or store their Maks in an unheated garage or shed for this reason.

 

So it depends on what is important to you. Portability, light weight, stability on a mount; the Mak is appealing. Top sharpness, contrast and a quick cool down; a refractor shines. Something for everyone.


Edited by Joe1950, 23 August 2019 - 06:36 PM.

  • Boom and bbqediguana like this

#96 PXR-5

PXR-5

    ISS

  • *****
  • Posts: 32208
  • Joined: 28 Mar 2008
  • Loc: NC

Posted 23 August 2019 - 06:37 PM

I own a 90, 127, and a 150. Fill in the blank LOL, I NEED the 102, if for nothing else, to drive Wifey crazy :)
  • eros312, bbqediguana and Joe1950 like this

#97 bbqediguana

bbqediguana

    Viking 1

  • *****
  • Posts: 930
  • Joined: 28 Feb 2015
  • Loc: Canada

Posted 23 August 2019 - 06:38 PM

I feel the same way, Rick. I have two ED glass refractors and inch for inch, they perform better than other designs. And there is a reason for that. All things being equal, such as diffraction limited quality, seeing and so on, a refractor, being a unobstructed scope (no secondary obstruction) should perform better than the same or similar size Mak.

 

A 30% or more secondary obstruction has significant negative impact on detail and especially contrast!

 

But, the Maks have their advantages. They do not suffer from chromatic aberration. Their long focal length helps moderate eyepieces perform better. The corrector and primary optics are spherical and much easier to mass produce with good quality than are scopes with aspheric elements.

 

And, their size lends itself to a stable, low vibration mounting situation. A long heavy refractor on a moderate size and weight (and cost) mount is prone to a back and forth movement known as a ‘moment arm.’ Focusing such a scope while it’s swaying like that is difficult!

 

On the side of refractors, they cool down much faster than any other design scope. Maks are known to take the longest of all types. Many put or store their Maks in an unseated garage or shed for this reason.

 

So it depends on what is important to you. Portability, light weight, stability on a mount; the Mak is appealing. Top sharpness, contrast and a quick cool down; a refractor shines. Something for everyone.

Hi Joe,

 

These are good points - but I think if you start looking at short tube refractors (especially ED and APOs), many of the advantages of the Mak disappear. The one I didn't think of was chromatic aberration - for sure my 70mm has that, but it's not at a level that is bothersome to me.

 

Thanks!

Rick


  • Joe1950 likes this

#98 Joe1950

Joe1950

    Cosmos

  • *****
  • Posts: 9596
  • Joined: 22 Aug 2015

Posted 23 August 2019 - 07:06 PM

True, a shorter FL ED or APO refractor are easier to mount and remain stable. Plus they do suppress or eliminate CA. And they cool much faster than a Mak. 

 

Per inch aperture, the Mak will still be shorter if you’re using a very lightweight grab and go mount. A 127mm Mak will be much shorter than any 127mm ED or APO refractor, since there is a limit to how short, with respect to the focal ratio you can go. Plus a shorter f-ratio APO, especially a triplet are much more difficult and time consuming to make, thus the cost is very high.

 

In all the aperture ranges, a major difference between a Mak and APO refractor is cost. And in the larger sizes the disparity becomes much greater. Someone wanting a 127mm or 150mm scope would pay a lot more for an ED or APO refractor.  And those sizes for a refractor are substantial regarding length and weight. 

 

So so there is always some reason a person might choose a Mak or SCT or a DOB. 

 

Believe me, if I were offered a 127 Fluorite Triplet, I wouldn’t turn it down. But if I had to buy a 127mm scope, it would  be a Mak or SCT or Newt.


  • bbqediguana likes this

#99 pdxmoon

pdxmoon

    Surveyor 1

  • *****
  • Posts: 1538
  • Joined: 27 Jun 2013
  • Loc: Oregon

Posted 23 August 2019 - 07:09 PM

It would be difficult for me to justify a C90 (although believe me, I'm trying!) I have really good small ED refractors: an AT60, and AT72. If I thought the images of the moon would be better than those, well the C90 becomes another tripod scope.

 

But I have NO DOUBT that the 127MAK is an advantage. It gives me great close up views, and especially as I find it less appealing to take out a 4" refractor on a heavier mount.


Edited by pdxmoon, 23 August 2019 - 07:11 PM.

  • bbqediguana and Joe1950 like this

#100 bbqediguana

bbqediguana

    Viking 1

  • *****
  • Posts: 930
  • Joined: 28 Feb 2015
  • Loc: Canada

Posted 23 August 2019 - 07:13 PM

Yes, I would agree that at 127mm, the Mak becomes a very good proposition compared to pretty much any refractor - especially when price is considered. But even without price, the Mak will be much more compact.


  • Joe1950 likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics