9.5 mirror & scope

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BABOafrica Kenya
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9.5 mirror & scope

#1

Post by BABOafrica »


I just finished an f/7.5 9.5in mirror and loaded it into the OTA. The mirror is NOT coated yet. Just glass. Well, the secondary is coated but not the primary.

The OTA is designed as an astrograph. I want to use it for astrophotography.

I'm just experimenting. I doubt that it will work well. Probably got some serious flexure problems (as you will summarize from the pictures of the OTA included below.) I had to keep the weight down to 20 pounds total, so... the whole thing is a bit flimsy.

Yeah, so probably not going to be a good astrograph. But you know how it is when it gets cloudy and you have a shop full of junk just waiting to be assembled into something useful. Who knows, it might surprise me and work quite well.

I did the mirror myself and tested with a Bath Interferometer (which I also made myself). Attached is an image of the wavefront resulting from the interferometer test plus a Ronchigram for the same mirror. You can see the mirror is a bit rough. But that doesn't matter as much with such a slow mirror.

I took a picture of a distant telephone tower (very cloudy day yesterday and supposed to keep raining). The image looks quite sharp to my eye. When the clouds go away and the moon comes back, I'll try to get some lunar shots.

In the meantime, here are the pictures:

THE OTA with the new mirror loaded:

441

442

438



Image of distant telephone tower (I used a Fujifilm X-A1)

443

447



Ronchigram of the mirror (outside RofC):

446


Interferometry test (using Bath interferometer and DFTF analysis) with Guassian blur set to 10%.
[[This is technically referred to as a "wavefront" showing the highs and lows on the mirror surface]]

445


Rochingram generated by DFTF analysis of wavefront:
[[If the DFTF Ronchigram matches the REAL Ronchigram (see above), it means that your interferometer test is good]]

444


Clears to YA!
BABO

PS Not sure why the images are failing to show up. I uploaded them to my album in the GALLERY section and copied the locations from there...
"In lumine tuo videbimus lumen."

Scopes: Stellarvue SV80 Raptor Carbon Fiber ED Doublet / Celestron SCT C8
Williams Optics 66mm APO / DIY 8" f/4 Newtonian astrograph / Nikon 180mm f/2.8
Mounts: Orion Atlas EQ-G / Celestron AVX / DIY mini-equatorial
Cameras: QHY163m / Fujifilm X-A1 (modded) / Fuji X-A2 (not modded) / Orion StarShoot Auto Guider
Filters: ZWO 7nm NB set / ZWO LRGB set / ZWO Dual Band / Astronomics UHC
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Lady Fraktor Slovakia
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Re: 9.5 mirror & scope

#2

Post by Lady Fraktor »


A nice project Babo, I hope it works out well for you.
Looking forward to some images with it :)
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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helicon United States of America
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Re: 9.5 mirror & scope

#3

Post by helicon »


Looking forward to seeing some of the pics it takes Joe. Congrats on the build.
-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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bladekeeper
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Re: 9.5 mirror & scope

#4

Post by bladekeeper »


Good stuff, Joe!

To get your images to show, you only want the number between the image tags.

So for [image]app.php/gallery/image/441/source[/image] remove everything but the 441...

441

I've fixed your original post. :)
Bryan
Scopes: Apertura AD12 f/5; Celestron C6-R f/8; ES AR127 f/6.4; Stellarvue SV102T f/7; iOptron MC90 f/13.3; Orion ST80A f/5; ES ED80 f/6; Celestron Premium 80 f/11.4; Celestron C80 f/11.4; Unitron Model 142 f/16; Meade NG60 f/10
Mounts: Celestron AVX; Bresser EXOS-2; ES Twilight I; ES Twilight II; iOptron Cube-G; AZ3/wood tripod; Vixen Polaris
Binoculars: Pentax PCF WP II 10×50, Bresser Corvette 10×50, Bresser Hunter 16×50 and 8×40, Garrett Gemini 12×60 LW, Gordon 10×50, Apogee 20×100

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Bigzmey United States of America
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Re: 9.5 mirror & scope

#5

Post by Bigzmey »


Fun project! Good luck!
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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