Maksutov + widefield telescope in one grab.

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John Baars Netherlands
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Maksutov + widefield telescope in one grab.

#1

Post by John Baars »


If you use a 102 mm Maksutov as a grab and go telescope you will have some issues.

1. Cooling down. It generally takes a long time before a Maksutov has reached equilibrium. Can't we make that shorter time? No we can't. But what we can do is to make sure the cooling has little effect on the image. How? By insulating the tube on the outside. This way the turbulence of the inside airflows are reduced.( radiation from the warm tube to the cold outside air is decreased) I can take my Mak outside and start observing almost right away. Just because it is insulated. It works.
Normally I use my 31 mm Baader Hyperion for 42X. I can use the 11 mm Nagler for 120X. On Jupiter I saw a transition of Callisto. Lunar craters are great. If I want I can use a 1.4X barlow as well for 170X on double stars. Propus was split with the Mak.

2. No wide-fields. The Mak in combination with a 2 inch Baader Hyperion gives a 1.3 degrees Real Field Of View. Some vignetting too. The Pleiades fit barely in. In order to view wide fields I mounted a finder / small telescope with interchangeable and rotatable eyepieceholder, on top of the Mak. It is a 50 mm f/4 achromat. I use a 11 mm Nagler to suppress more or less the aberrations of the f/4 system. It gives a 4.4 degrees RFOV and a magnification of 18.5X. Enough to find faint stars for starhopping in my LP skies and to enjoy nebulae in the Milky Way under darker skies.
IMG_1443 (638x850).jpg
In order to find stars a reddot finder was added. The holder I had from an earlier experiment can hold three accessories. I find a bright star nearby with the red dot. I switch to the widefield telescope / finder for a better view of the whole field and hop to the target. Nice to see the target in the finder telescope. (I usually don't, with 10X50 under LP skies). Turn my head a bit and there it is, in the main scope!
IMG_1447 (638x850).jpg
This my point of view.

The whole telescope-group weighs about 9 pounds. The very sturdy AltAz mount with slow/mo controls weighs 12 pounds. I can lift the whole system with one arm and carry it 4 meters further, into the garden.
IMG_1445 (638x850).jpg
This is what the fotons of the Sun see, a split second before they enter my grab & go.
( photo is taken on fourth of May, memorial-day, you can see the red, white and blue of the Dutch flag mirrored)
Refractors in frequency of use : *SW Evostar 120ED F/7.5 (all round ), * Vixen 102ED F/9 (vintage), both on Vixen GPDX.
GrabnGo on Alt/AZ : *SW Startravel 102 F/5 refractor( widefield, Sun, push-to), *OMC140 Maksutov F/14.3 ( planets).
Most used Eyepieces: *Panoptic 24, *Morpheus 14, *Leica ASPH zoom, *Zeiss barlow, *Pentax XO5.
Commonly used bino's : *Jena 10X50 , * Canon 10X30 IS, *Swarovski Habicht 7X42, * Celestron 15X70, *Kasai 2.3X40
Rijswijk Public Observatory: * Astro-Physics Starfire 130 f/8, * 6 inch Newton, * C9.25, * Meade 14 inch LX600 ACF, *Lunt.
Amateur astronomer since 1970.
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Lady Fraktor Slovakia
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Re: Maksutov + widefield telescope in one grab.

#2

Post by Lady Fraktor »


A wonderful write up John, thank you :)
See Far Sticks: Antares Elita 103/1575, AOM FLT 105/1000, Bresser BV 127/1200, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS100/1000, Vixen SD115s/885
EQ: TAL MT-1, Vixen SXP, AXJ, AXD
Az/Alt: AYO Digi II/ Argo Navis, Stellarvue M2C/ Argo Navis
Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102
Diagonals: Astro-Physics, Baader Amici, Baader Herschel, iStar Blue, Stellarvue DX, Takahashi prism, TAL, Vixen flip mirror
Eyepieces: Antares to Zeiss
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Bigzmey United States of America
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Re: Maksutov + widefield telescope in one grab.

#3

Post by Bigzmey »


Nice rig John! Dual setup of Mak/SCT with faster refractor is my favorite way to observe.
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
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Re: Maksutov + widefield telescope in one grab.

#4

Post by notFritzArgelander »


Nice setup. I used to employ the same strategy with my VMC110L an open tube field Maksutov operating at f9.4. It has no 2" eyepiece capability so I am limited to 1.25".

I had a very fast 70mm f4 finder that I would mount on it, the Orion Multi Use Finder scope. That was a very satisfactory combination for a while, but I missed having a red dot finder. Since the VMC110L comes equipped with a flip mirror I removed the optical finder in favor of restoring the red dot unit and in the top port of the flip mirror I started using a GSO 1.25" 0.5x reducer screwed into the filter threads of a Meade HD60 25mm eyepiece.

This combination gives me a magnification of 20x, a TFOV of 2.9 degrees (so Pleiades is VERY nice in it) and an exit pupil of 5.32. At a dark site that is perfect for appreciating larger nebulae.

There are two possible drawbacks to this set up one might consider and both have workarounds.

1) One cannot simultaneously collimate the straight and bent ports of the flip mirror on the VMC110L. This is not really a problem. I collimate for the straight through port and attach a mirror diagonal for higher magnification use and use the bent flip port for low power viewing. This is perfectly acceptable from a collimation POV. The difference in collimation is not great enough to be seen unless you operate both ports at high magnification.

2) Vignetting.... I'm sure if it had a 2" back it would be there but with only a 1.25" back I don't see any vignetting at all. On my MK66 the 2" Intes 0.5x reducer vignettes like crazy and the GSO is milder but usable. I'm going to see what happens on the VMC200L soon when a flip mirror for it arrives.

I've become fond of flip mirrors on Maks I guess. :)
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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John Baars Netherlands
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Re: Maksutov + widefield telescope in one grab.

#5

Post by John Baars »


Just for fun:
Two snapshots of the Moon with cellphone behind the eyepiece with a simple adapter. Taken through the 102mm Mak on the 4th of May 2020.
Tip: Use the selftimer of the phone in order to be sure all movements of camera and telescope are gone before the shutter releases.
IMG_E1457 (1350x1800).jpg
IMG_E1462.JPG
Refractors in frequency of use : *SW Evostar 120ED F/7.5 (all round ), * Vixen 102ED F/9 (vintage), both on Vixen GPDX.
GrabnGo on Alt/AZ : *SW Startravel 102 F/5 refractor( widefield, Sun, push-to), *OMC140 Maksutov F/14.3 ( planets).
Most used Eyepieces: *Panoptic 24, *Morpheus 14, *Leica ASPH zoom, *Zeiss barlow, *Pentax XO5.
Commonly used bino's : *Jena 10X50 , * Canon 10X30 IS, *Swarovski Habicht 7X42, * Celestron 15X70, *Kasai 2.3X40
Rijswijk Public Observatory: * Astro-Physics Starfire 130 f/8, * 6 inch Newton, * C9.25, * Meade 14 inch LX600 ACF, *Lunt.
Amateur astronomer since 1970.
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Ylem United States of America
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Re: Maksutov + widefield telescope in one grab.

#6

Post by Ylem »


Nice pics!

I have a Celestron C90 :)
I put an SCT thread adapter on mine, then added the .63FR/C on mine. I get about 2° FOV with that set up using a 32mm Plossl or my 24 Pan :)

I love little Maks :)
Clear Skies,
-Jeff :telescopewink:


Member; ASTRA-NJ



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Re: Maksutov + widefield telescope in one grab.

#7

Post by helicon »


Excellent shots John.
-Michael
Refractors: ES AR152 f/6.5 Achromat on Twilight II, Celestron 102mm XLT f/9.8 on Celestron Heavy Duty Alt Az mount, KOWA 90mm spotting scope
Binoculars: Celestron SkyMaster 15x70, Bushnell 10x50
Eyepieces: Various, GSO Superview, 9mm Plossl, Celestron 25mm Plossl
Camera: ZWO ASI 120
Naked Eye: Two Eyeballs
Latitude: 48.7229° N
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Re: Maksutov + widefield telescope in one grab.

#8

Post by StarBru »


Great tips on improving and making a small MAK more user-friendly, John! Great pics of the moon, too!
Bruce

Refractors: Meade AR-5 127mm f/9.3, Meade ST-80 f/5 and Meade 60mm f/12, Jason 60mm f/15 #313, Jason 60mm f/12 #306 S7, Bushnell Sky Chief III 60mm f/15.
Reflectors/Catadioptrics: Meade 10" F/4 Schmidt-Newtonian, Galileo 120mm f/8.3 Newtonian, Meade 2045D 4" f/10 SCT, Meade ETX-90EC f/13.8 & Sarblue 60mm f/12.5 Maksutov-Cassegrains.
Mounts: Skywatcher EQ6-R Pro & Meade LXD55 Equatorial mounts, ES Twilight II and Meade 2102 ALT/AZ mounts, a modified 10" SkyQuest Dobsonian mount, various 60mm EQ mounts.
Misc: Celestron 20x80mm binoculars, Revolution II Imager/accessories, & lots of optical accessories/eyepieces.
Projects: 8" f/2.9 and 65mm f/10 reflectors, Dobson-style binocular mirror mount.
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