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Share my home made 250mm big binoculars

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#76 JKoelman

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Posted 02 October 2012 - 08:28 AM

The optical system is reflected by two plane mirrors, and then use Japan EMS optical system .
Erecting Mirror System invented by Tatsuro Matsumoto
http://www.page.sann...oto/intro-e.htm

Thanks, great info. What optical precision are you targeting for the first and second flats? Did you consider tilting the two flat mirrors to make the two beams cross (in-between the two reflections), so as to render the bino even more compact?

#77 glennnnnnn

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Posted 02 October 2012 - 09:29 AM


Great craftsmanship and a fantastic job!

#78 Mike I. Jones

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Posted 03 October 2012 - 09:05 AM

Luciano,
How do you vary the interocular distance? What parts translate or rotate? The 2-mirror EMS system is a nice innovation, but the geometry looks like it must be fixed to simultaneously maintain image alignment and co-planarity. Do you simply vary the distance between the two separate OTA's in translation?

Great project, thanks so much for posting.
Mike

#79 killdabuddha

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Posted 03 October 2012 - 09:42 AM


Just beautiful. The future is two-eyed. Thanks Luciano.

#80 luciano

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Posted 15 October 2012 - 10:29 AM

Luciano,
How do you vary the interocular distance? What parts translate or rotate? The 2-mirror EMS system is a nice innovation, but the geometry looks like it must be fixed to simultaneously maintain image alignment and co-planarity. Do you simply vary the distance between the two separate OTA's in translation?

Great project, thanks so much for posting.
Mike

Jones,
Sorry! My English is not good. Is not completely clear explain to you. Had a simple explanation with pictures.
Will be issued after the completion of more 203 big binoculars tuning method.
I hope you can understand the structure of more 203 big binoculars.

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#81 Gordon Rayner

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Posted 16 October 2012 - 07:05 PM

The Matsumoto EMS , which the Luciano Jorge
Ricci (Macau), designs resemble, provide variable interpupillary distance through variable separation between the mirrors in each mirror pair. A refocus is needed after an IPD change.


Matsumoto-San used Pentax 67 accessory focusers. There is no relative rotation of the entrance and the exit. Only a hand grip rotates, to swell or to shrink the axial length, and thus the separation of the two mirrors.

Several WWII Zeiss designs, including the 12 x 60 and the 25 x 100, each of which have 60 deg. inclination of the line of sight, provide IPD adjustment by lateral motion of one eyepiece only. The roof prism assembly which feeds the laterally moving eyepiece is linked to that eyepiece via a Cardano circle geared mechanism, such that the prism assembly moves by half of the eyepiece lateral motion. No refocus is required after an IPD change.


I wrote a general program for the hp48, which follows the WW II Zeiss scheme. If one is not hurried, the adjustment can be without linkage, which very much simplifies construction. A reversed, eyepiece-less binoviewer, or a handheld beam combining comparator such as the JTII, assist in correct adjustment for lateral parallelism ( and for checking parallelism of the sight lines up-down) of the lines of sight, for a given IPD.

The program has variable ( but fixed when chosen) inclination of the sight line, optimized position of the phantom roof line for some 5 different flat mirror shapes, variable mirror thicknesses and presence/absence of taper and/or edge bevel,variable objective diameter and f/number, variable linear field diameter at the focal plane, and maybe some other variables . I have not worked with it recently.

The situation is three-dimensional, involving compound angles. The hp 48 does not directly manipulate 3D vectors, so some programming tricks from the William Wickes hp 48 book provided a solution. He was the software engineering head for the hp 48 development.

#82 JWW

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Posted 17 October 2012 - 10:52 PM

Very creative, thanks for sharing.

-JWW:

#83 Flappytango

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Posted 21 October 2012 - 02:53 PM

Incredible DIY!

#84 Rutilus

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Posted 21 October 2012 - 03:20 PM

Outstanding projects. Your skills are fantastic.

#85 Mike I. Jones

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Posted 21 October 2012 - 11:42 PM

Got it, thanks! I built a model of your mirrors in ZEMAX and varied the interocular distance (IOD) as you described. This diagram is for two 8" f/7 achromats, and uses standard 4" and 1.83" Newtonian telescope diagonals for the fold mirrors.

A very clever design indeed. I don't see refocusing the individual eyepieces after varying IOD as anything of major inconvenience.

Mike

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#86 Gordon Rayner

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Posted 23 October 2012 - 03:01 AM

Another way to look at these phantom roof designs is the good drawing of an Amici prism in the second mode in which the light cone is not divided by the (phantom) roofedge, in Mil Handbook 141, available online, via CN, from the University of Arizona.


An error in the 90 degree angle of the phantom roof ( not related to the usually chosen 90 deg. inclination of the view) causes image rotation. If one is lucky, errors would tilt the images by the same amount in both telescopes.

Mentally replace the Mil Hndbk 141 Hopkins chapter tracings of the beamprints ,of the light cone upon the roof surfaces, by mirrors . At 90 degree inclination of the overall sight line, those ellipses have a 2:1 major/minor axes ratio.

In this example, the axial ray makes a 60 deg. angle with the mirror surfaces. What effect does this have on "enhanced" reflectivity mirrors, which are listed in catalogs as optimized for 45 deg, or for zero degree, angle of incidence ?
We have been told that the reflectivity peak shifts toward the blue. But by how much? Of cource, the enhancing lab's coater could adjust the peak reflectivity to be at 60 deg. incidence. That is non-catalog, custom work, $$$(?). Is it a simple matter of turning a dial, or would it require a redesign of the enhanced reflectivity coating?

#87 PeterKA

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Posted 09 November 2012 - 11:35 PM

These two mirror erecting systems can be very effective. But they introduce another variable in collimation & alignment -- image rotation. This can be corrected, but like all 'on the fly', visually adjusted alignment - it is subject to the acuity and meticulousness of the individual making the adjustment. The Matsumoto systems I've tried (two occasions I believe) were not correctly adjusted for rotation, and the left image was rotated relative to the right. Apparently the owner was not noticing this, but it was a headache inducer to me.
Peter Abrahams

Got it, thanks! I built a model of your mirrors in ZEMAX and varied the interocular distance (IOD) as you described. This diagram is for two 8" f/7 achromats, and uses standard 4" and 1.83" Newtonian telescope diagonals for the fold mirrors.

A very clever design indeed. I don't see refocusing the individual eyepieces after varying IOD as anything of major inconvenience.

Mike



#88 luciano

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Posted 30 December 2012 - 12:36 AM

Is a one small step. Complete focuser.

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#89 PitchHitter

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Posted 08 February 2013 - 10:04 PM

Very beautiful work. I didn't see baffling but that would be easy to add. I had a chance to view through DKDs before. Everybody was impressed with the big glass except me. The image scale was enough to exhibit poor chromatic aberration. I have used large, achromats and they can provide far better images than any DKDs I have seen. I felt the focus to be soft too. The best price here in the US was about $2,500 ea. I have heard they may have come down some. An old C-8 at the star party performed better, weighed less. I bought a great C-8 OTA from my friend Craig at OPT just a couple of years ago for $200 Used. For binoculars, the primary is just a start, it is the tail that makes or breaks the package. I am guessing 40mm eyepieces will yield around 32x so perhaps the optical defects will be tolerable for most. It still should yield some fantastic dark sky nebula views. One must have perspective.

#90 Gordon Rayner

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Posted 09 February 2013 - 02:46 AM

The EMS focuses by varying the mirror separation. That introduces , unavoidably, some mechanical tolerance in the 90 degree angle between the mirrors. This may be the source of the image rotation which Peter mentioned .

But if each 2-mirror "prism" is a rigid unit, with no variation of intermirror separation, the control of image rotation ("lean") can be more definite. In this case, focus for each eye is made by helical threads or other usual techniques.

Such a system is in the April, 2012 Sky & Telescope,via separation of each telescope, or in the system described above in the hp 48 program, ff. WW II Zeiss 12 x 60 or 25 x 100, etc.

#91 Gordon Rayner

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Posted 09 February 2013 - 02:48 AM

What or who is DKD?

#92 obin robinson

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Posted 09 February 2013 - 06:41 PM

This project simply blows me away. The machining is excellent. It's the creativity and ingenuity which impresses me even more.

Good job! Bravo!

obin :bow:

#93 issa

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Posted 06 May 2013 - 05:57 AM

hi, i have a question:

Q1: what is the price of 250 mm Luciano binocular
including the GO TO MOUNT and the freight charge to my country Jordan?

kind regards

kissa

#94 luciano

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Posted 07 June 2013 - 11:53 AM

Two month later I hope to complete this project.

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#95 luciano

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Posted 07 June 2013 - 11:54 AM

Picture 01

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#96 luciano

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Posted 07 June 2013 - 11:55 AM

Picture 02

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#97 luciano

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Posted 07 June 2013 - 11:56 AM

Picture 03

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#98 luciano

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Posted 07 June 2013 - 11:57 AM

Picture 04

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