Author Topic: The PiKon telescope  (Read 280 times)

Kenneth Naim

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The PiKon telescope
« on: December 29, 2017, 02:47:32 AM »
Hi All

I was doing a search on 3D Printing Telescopes and ran across this neat little DIY telescope.

after reading the info about The PiKon telescope. I think you could Mod most newton telescope with the info here.

This is a very interesting idea.

It i s called the The PiKon telescopeHow It Works
The PiKon telescope is based on the Newtonian reflecting telescope. This 350-year-old design uses a concave mirror (objective) to form an image, which is examined using an eyepiece. The objective mirror is mounted in a tube and a secondary mirror is placed in the optical path at a 45° angle to allow the image to be viewed from the side of the tube.
The PiKon telescope is similar, but the image formed by the objective is focused onto a digital camera sensor instead. Because of the small size of the Pi camera board (25mm × 25mm), we can mount it directly in the optical path at prime focus. The amount of light lost by doing this is similar to the losses caused by mounting the 45° mirror in a conventional Newtonian design.Don

Here is the link

http://makezine.com/...y-pi-telescope/



Justin Lewis

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Re: The PiKon telescope
« Reply #1 on: December 29, 2017, 04:46:04 AM »
What is the difference compared to a lensless Schmidt-camera?

Trendsetters Branch

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Re: The PiKon telescope
« Reply #2 on: January 08, 2018, 04:14:18 AM »
"What is the difference compared to a lensless Schmidt-camera?"

what is a lensless Schmidt-camera?

I will research that.
///////////////////////////////
OK research that

From what i understand about the PiKon telescope is they are trying to eliminate the secondary mirror and replace it with a smaller camera that will block less light to the primary mirror.

The lensless Schmidt-camera still has the light blocking secondary mirror.

Don

tranardefa

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Re: The PiKon telescope
« Reply #3 on: January 12, 2018, 01:10:09 AM »
Ok thats pretty cool. I might try to build one. Looks like they should have used a parabolic rather than A f5 spherical mirror though.

Looking at the camera options, they even have one set up with no Ir filter.

Brandon Costello

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Re: The PiKon telescope
« Reply #4 on: January 14, 2018, 05:32:19 AM »
A lensless Schmidt also has no secondary mirror.

Richard Ross

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Re: The PiKon telescope
« Reply #5 on: January 23, 2018, 01:44:25 AM »
some of the hi def camera chips are getting pretty small. on a single stock it would block even less light.

Don

Tawakal Stahlberg

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Re: The PiKon telescope
« Reply #6 on: January 25, 2018, 09:21:29 PM »
Quote
A lensless Schmidt also has no secondary mirror.

show me please. what i have research showed a secondary mirror in place.

Don

Derrick Matlock

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Re: The PiKon telescope
« Reply #7 on: January 31, 2018, 05:35:33 AM »
When Hale telescope was used with an observer in the prime focus "tube" that telescope was using exactly the same optical arrangement as the PiKon--only 70 years earlier.

Eric Graf

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Re: The PiKon telescope
« Reply #8 on: January 31, 2018, 07:51:37 AM »
Quote
Quote

A lensless Schmidt also has no secondary mirror.

show me please. what i have research showed a secondary mirror in place.

Don

llsc.jpg
Hi,

In the diagram you will notice the diameter of the stop is less than that of the spherical mirror.

When you place a stop at the radius of curvature of the mirror it eliminates spherical aberration. But to fully illuminate the field off axis the mirror has to be larger than the stop.

The diagram has a Newtonian secondary for convenient camera placement.

If you look at the Mount Palomar Schmidt pictures you can see this effect on the overall shape.

In the days of film they had a curved film holder at the prime focus which the film was pressed onto to take into account the curved field.

If you put you Pi camera at prime focus then off axis aberration's of the Newtonian mirror will still be in play. For a parabaloid Coma and field curvature. But as its a small chip not much of a problem.

Cheers. Andrew.

Sean Schaefer

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Re: The PiKon telescope
« Reply #9 on: January 31, 2018, 01:39:52 PM »
Quote
From what i understand about the PiKon telescope is they are trying to eliminate the secondary mirror and replace it with a smaller camera that will block less light to the primary mirror.

...only to spoil it with very very thick printed spider vanes. There may be a place for printed plastic on a telescope, but this isn't the place or the execution.

pmethinxlamna

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Re: The PiKon telescope
« Reply #10 on: February 02, 2018, 01:24:52 PM »
yes i seen the thick spider. i thought the same thing.But if you make a pcb the size of the ccd chip and but it up a flat pcb with all the electronic components on it behind the ccd chip.
then have it extend to the telescope tube like a flat single stock secondary mirror that would work.

o heck a picture is worth a thousand words.

date 5/1/2017 11:02 AM. for copyright proposesDon

retaweawebs

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Re: The PiKon telescope
« Reply #11 on: February 02, 2018, 10:59:37 PM »
Putting a camera at prime focus isn't a new idea. Hyperstar/fastar is probably the most common application, but there are others. The referenced project seems like a make-work project to promote 3D printing and Raspberry pi, which are Make magazines stock in trade rather than a serious attempt at a useful system.

For a somewhat more sophisticated take on the 3-D printed camera-at-prime-focus idea, there is this project from the EAA forum.https://www.cloudyni...elescope/page-3. I still think collimation and alignment will be a problem, but it's definitely an interesting idea. I think a 3-support version with adjustment on each (essentially creating a Steward platform) would be ideal - move in unison to focus, move individually to collimate. You still have a potential alignment/centering problem, but if you're basically accurate I think that could be solved with collimation screws on the primary.

Jason Hillyer

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Re: The PiKon telescope
« Reply #12 on: February 09, 2018, 04:45:58 AM »
The Stewart Platform provides for all centering a collimation requirements.