Telescope Reviews: Severe case of Aperture Fever

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General Astronomy >> General Observing and Astronomy

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DOTrevino
member

Reged: 11/16/09

Severe case of Aperture Fever
#5522557 - 11/16/12 10:08 AM

I watched this last night in the local news. Quite a severe case.

click here

Post Extras:

JayinUT
I'm not Sleepy

Reged: 09/19/08

Loc: Utah

Re: Severe case of Aperture Fever new

[Re: DOTrevino]
#5522620 - 11/16/12 10:40 AM

I dropped off some mirrors for Carl at Nova this last summer with a friend and saw this out at Steve's garage. It is truly an amazing thing Mike and Steve are doing here. Here's wishing them all the luck in the world in getting it done and if they need some local help there's a group of us that would love to help. I will say, what an ATM project!

Post Extras:

star drop
Snowed In

Reged: 02/02/08

Loc: Snow Plop, WNY

Re: Severe case of Aperture Fever new

[Re: DOTrevino]
#5522626 - 11/16/12 10:43 AM

Aperture fever indeed!

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csa/montana
Den Mama

Reged: 05/14/05

Loc: montana

Re: Severe case of Aperture Fever new

[Re: JayinUT]
#5522654 - 11/16/12 10:52 AM

Jay, if Mike is not a CN'r; maybe he would care to join, and share his experience of the builds!

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mwt
member

Reged: 02/15/12

Loc: W. Mass

Re: Severe case of Aperture Fever new

[Re: csa/montana]
#5523121 - 11/16/12 04:07 PM

Wow....how do you calculate the size of the secondary??

Post Extras:

GpB311
sage

Reged: 05/29/12

Loc: Los Angeles, CA

Re: Severe case of Aperture Fever new

[Re: mwt]
#5523168 - 11/16/12 04:38 PM

Id pay just to look through it for a minute.

Post Extras:

Tim Gilliland
professor emeritus

Reged: 03/28/09

Loc: Sand Springs Okla.

Re: Severe case of Aperture Fever new

[Re: GpB311]
#5523181 - 11/16/12 04:48 PM

Quote:

Id pay just to look through it for a minute.

Post Extras:

skyward_eyes

Reged: 12/12/06

Loc: California

Re: Severe case of Aperture Fever new

[Re: Tim Gilliland]
#5523277 - 11/16/12 06:12 PM

Haha I know him. His been working a long time on this. Truly a follow your dream story

Post Extras:

TileArt
member

Reged: 09/13/12

Loc: Fort Collins, Colorado

Re: Severe case of Aperture Fever new

[Re: skyward_eyes]
#5523548 - 11/16/12 10:19 PM

I'd love to look through that just once.

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Ed D
Carpal Tunnel

Reged: 04/30/10

Loc: Sunny South Florida

Re: Severe case of Aperture Fever new

[Re: TileArt]
#5523965 - 11/17/12 08:57 AM

If he mounts this behemoth on a tractor trailer, like he did with his 'smaller' scope on the pickup truck, it would probably make it the ultimate grab and go!!!

Ed D

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Starry eyes
member

Reged: 04/30/10

Re: Severe case of Aperture Fever new

[Re: Ed D]
#5524205 - 11/17/12 11:31 AM

So this is where that 70" is now. Actually the 70" blank is a Corning Pyrex that was cast as part of the scaling up process that culminated in the 120" Shane Telescope and the 200" Hale. It was originally made for a spectrograph, then found it's way to Tasmania where it languished until the late eighties when it was acquired by group 70. It had a sizable sagitta cast by bricks. It also had about a 1:6 thickness to diameter ratio so is a bit heavy. We always wondered about the cool down time!

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Seldom
sage

Reged: 08/05/12

Loc: Southwest Utah--Elev. 5700 ft.

Re: Severe case of Aperture Fever new

[Re: Starry eyes]
#5524363 - 11/17/12 01:23 PM

Anyone have an idea what the focal length is?

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csrlice12
Post Laureate

Reged: 05/22/12

Loc: Denver, CO

Re: Severe case of Aperture Fever new

[Re: Seldom]
#5524426 - 11/17/12 02:05 PM

I'd say that goes a little beyond Amateur Astronomer. Is he looking to adopt? I'm available, I don't eat much.

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BigC
Carpal Tunnel

Reged: 09/29/10

Loc: SE Indiana

Re: Severe case of Aperture Fever new

[Re: GpB311]
#5527675 - 11/19/12 10:46 AM

You do realize that once you looked through the 70 inch ,nothing smaller will be acceptable ?!

Some years ago,several lucky amateurs were able to view with the 100 inch -forget just where I read about it. But moons of Jupiter were describes as orbs,not disks.

Wonder if there are any more of those spy mirrors available ??

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Edward E
professor emeritus

Reged: 03/26/06

Loc: Tucson, Arizona

Re: Severe case of Aperture Fever new

[Re: Seldom]
#5527678 - 11/19/12 10:47 AM

At 70", if it was an f3 that would mean a minimum eyepiece height of 19 ft!

I would love to look through the scope but not climb the ladder to the eyepiece!

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csrlice12
Post Laureate

Reged: 05/22/12

Loc: Denver, CO

Re: Severe case of Aperture Fever new

[Re: Edward E]
#5527680 - 11/19/12 10:50 AM

You could go to the Military surplus auctions...they're always selling unneeded stuff; like rolling staircases/ladders they use for aircraft maintenance.....Portable, no, but neither is a 70" scope....

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Seldom
sage

Reged: 08/05/12

Loc: Southwest Utah--Elev. 5700 ft.

Re: Severe case of Aperture Fever new

[Re: Edward E]
#5527803 - 11/19/12 11:58 AM

Quote:

At 70", if it was an f3 that would mean a minimum eyepiece height of 19 ft!

I would love to look through the scope but not climb the ladder to the eyepiece!

Maybe he's got something in mind like Herschel's 48" scope, or Lord Rosse's "Leviathan of Parsontown". Also, IIRC the blank wasn't silvered (aluminized). I wonder where he can get that done?

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coopman
Carpal Tunnel

Reged: 04/23/06

Loc: South Louisiana

Re: Severe case of Aperture Fever new

[Re: Seldom]
#5527867 - 11/19/12 12:39 PM

I hope that he has a structural engineer checking the framework that he is building to support the mirror. I would not have a good feeling if I were "winging" this part of the scope design.

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csrlice12
Post Laureate

Reged: 05/22/12

Loc: Denver, CO

Re: Severe case of Aperture Fever new

[Re: Seldom]
#5527871 - 11/19/12 12:41 PM

Theres an old radio telescope for sale in South America I believe. Maybe coat that thing with a mirror surface with the objective lens in orbit????

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Dave Mitsky
Postmaster

Reged: 04/08/02

Loc: PA, USA, Planet Earth

Re: Severe case of Aperture Fever new

[Re: csrlice12]
#5528023 - 11/19/12 01:51 PM

Is it a parabolic or hyperbolic primary mirror? Aren't spy satellites equipped with variations of the Ritchey-Chretien Cassegrain design or three-mirror astigmats?

Dave Mitsky

Post Extras:

FirstSight
Postmaster

Reged: 12/26/05

Loc: Raleigh, NC

Re: Severe case of Aperture Fever new

[Re: Dave Mitsky]
#5528326 - 11/19/12 04:18 PM

There's a paradox for even the most avid amateur astronomer:
- the larger the aperture, the brighter and deeper the objects you can see BUT:
- the objects at the edge of visibility won't be any brighter than the objects that were at the edge of visibility in aperture several inches smaller AND there will be at least as many objects that are beyond the range of the current larger aperture scope you have as were beyond the range of the several inches smaller aperture scope you had before.

Not only that, but in darker skies than you have, you could see just as bright and deep with your smaller aperture scope than you can in your less dark skies with your larger aperture scope.

MORAL(s): aperture rules, but the size of the kingdom it rules is limited by how dark the skies are it's used under; also, there's always a swarm of galaxies and clusters that are just over the boundaries of your averted vision, no matter what aperture you have or how dark your skies.

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GeneT
Ely Kid

Reged: 11/07/08

Loc: South Texas

Re: Severe case of Aperture Fever new