正立ミラーシステム(EMS)を開発した松本龍郎のサイト。 たった2回の反射で天体望遠鏡の像を正立像にします。
Tatsuro Matsumoto; Inventor of the EMS, Erecting Mirror System. EMS offers non reversed upright image with no additional undesirable abberations.
EMS-ULTIMA, equipped with enhanced silver coated mirrors, is coming soon. The graph above shows its extraordinary reflectivity.
Dark blue line shows the relfectivity of one reflection, and light blue line shows that of two times reflectons. Note that the scale of the bottom of table is not “zero”, but “75 percent”.
Now that EMS has achieved not only the diffraction limited resolution but also the practically total reflection of the incoming light, there will be no reason even for the most conservative users to dispense with EMS in their visual observation.
I believe it declares the advent of the new age of visual Telescopes.
It has been well known that Silver inherently has very high reflectivity through the visible spectrum except for the violet. But at the same time, it is also widely known that Silver degrades rapidly. So a Silver coating has not yet replaced aluminum in spite of its attractive features.
Not yet, but not “not from now on”.
Now, EMS-ULTIMA is breaking the age long stereotype as a past one. Recently developed enhanced silver coating has achieved super high reflectivity through the total visible spectrum including violet and enough durability allowing the continual use in the air at the same time, and I have developed the way to realize it on the mirror of EMS overcoming many difficulties.
The average reflectivity through the visible spectrum per one mirror is as high as 98.5 percent, and 97 percent of the incoming light is secured even after 2 times of reflections.
Following is the history and process I have traced before reaching this ultimate goal.
Attaining erect image at the right angle viewing with only two reflections itself is unexcelled feature of the EMS that cannot be substituted by any other devices. Judging from the least possible number of the reflection,”2″ of EMS, compared with the traditional devices of 4 or 6 times reflections, originally I did not think it urgent to additionally improve the reflectivity of the mirrors. So, I had chosen the traditional mirror of the highest visible reflectivity with time proven durability, among those that were available at that time.
The answer was “enhanced aluminum coating” that is the aluminum coating over coated by some layers of dielectric to boost the reflectivity of the normal aluminum and at the same time to enhance the surface durability.
Dielectric coating is becoming popular recently for its alleged remarkable reflectivity. But, regrettably, recent investigations showed that it is not suited for the purpose of higher index-angle, such as 60 degrees of the EMS, and thicker light cone of brighter optics of F/5 or shorter that should contain rays of wide range in index-angles. Dielectric coating is very critical about index-angles and causes unwelcome polarization, and we should know that the perfect reflection is given only under the optimum condition originally intended in the plan. Even by customizing the layer thickness and increasing the number of coatings up to hundreds layers to overcome the degradation at the higher index-angle, unwelcome byproduct effect will balance out the merit of its original super high reflectivity, along with the inflation of the cost.
Concretely speaking, there is a tendency of shortening the width of the peak plateau of the reflectivity, peak shifting to the shorter wavelength direction (violet shift), and cause drastic down turn at the longer wavelength or the counterpart.
I have done some experiments on three kinds of coatings to check which is the most excellent and suitable choice for my purpose. Seeing the results of the experiments will help you understand why I have chosen the enhanced silver coating as the ultimate one for my EMS.
If you hold a pair of mirrors in such a way that two surfaces closely face each other, and obliquely poke into the gap, you will see the endless line of your eyes of multiple reflections.
The largest image of the camera lens is the direct, number 1, reflection image and next to left will count up to 5,7,9,….times reflected images. Left photo is enhanced aluminum and the right is enhanced silver. いずれの写真も、右端の大きなカメラレンズが1回反射の像で、3回反射の像はどちらかのミラー の陰になって撮影できず、5回反射以降の像が写っています。写真に番号を振りました。左に行くほど 反射回数が増えます。 可視光線平均としては95%の高反射率を誇る増反射アルミであっても、 赤い光線の落ち込みによって、カラーバランスがどんどん崩れて行くのが顕著です。 また、デジカメのレンズ部だけでなく、ミラーを保持する私の指先も写っていますが、 銀ミラーでは、その健康な血色が20回反射を超えてもまったく褪せないことは驚きに値します。
Test2: multiple reflection experiment-2;
Two mirrors faced to each other in such a way that forward end touch each other like a book slightly opened. The set stayed on my visiting card. In this experiment, dielectric one showed worst in contrast, though brightness was rather good. (direct image is marked by a red circle.)
Test3:transparency test on dielectric mirror; テスト3:誘電体多層膜の透過テスト;
I found rays passing through dielectric coating. If it reflects 98 percent of the incoming light, 2 percent of the light seems to go through it. I thought it very unwelcome feature when I aim at the superb image contrast. The photo witnesses the fact of the diode flashlight passing through the dielectric mirror.
From top to bottom, dark blue line represents one reflection by enhanced silver, light blue that of two reflections, red line one reflection by enhanced aluminum, green line that of two reflections.
You will find not only the extraordinary high reflectivity of the enhanced silver, but also the remarkable flatness of the line. Through these experiments, I have studied the fact that the flatness of the line is as important as the highness of it.
(No image processing has been done on the above photos of experiments except for trimming. And I must add that the silver sample mirrors were almost two years old since deposition at the experiment.)
I musn’t forget to extend my sincerest appreciaton to some of my friends who have assisted me devotedly. They have given me a lot of information about the silver coating and even have done durability experiments.
Above all, their encouragement helped me a lot to keep up going wih this difficult project.
I am sending you photos of my completed binoscope. All is perfect.
I am enjoying the views very much. My self-made mount functions very well in all respects. I even find no need to add any friction adjustment capability, because the adjustable stainless steel weights allow perfect quick adjustment for fine balance with any eyepiece pair to perfectly hold any altitude. Of course, this idea was given to me from the photograph of the TOA-130 binoscope on your web site. It was a very good idea and I thank you for it.
Perhaps the only disadvantage of the TOA-130 is the heavy weight, which requires more careful setup and take down, especially the take down in the dark. But of course the big advantage is the optical near perfection.
I am not exactly happy with these photos, because it is hard to see detail of the black mount when the sky background it so bright. I hope to take some better photos on a cloudy day to send you some better photo.
Thank you for the link. Now, yes, I would like to add to my report these comments:———————————–
Tatsuro, I want to thank you very much for your EMS backs that I purchased from Joe Castoro. Your EMS backs are very fine craftsmanship, and your design is very elegant. The system is easy to collimate and merging views is always easy. And I really appreciate the views that are oriented correctly up/down and left/right. The various adjustments have become easy to accomplish now with very little thought. This is all made possible by your great EMS invention.
Thank you for suggesting that I should use your Extra Large 65mm EMS backs. These TOA-130 are rather large diameter, and the Extra Large backs allow the tubes to be spaced a wider distance apart. I think assembly of the system would be less convenient with the 50mm EMS backs requiring closer spacing of the telescopes. Plus I am happy to know that there is never any vignetting with this system.
My eyesight is not perfect. My left eye has a little astigmatism, and my right eye has more astigmatism. The merging of two eye views results in an image quality that helps very much to overcome the defects of my eyesight, without wearing glasses. Thank you for making this possible.
I would also like to thank Joe Castoro for his advice and assistance in helped me to make a successful binoscope. Joe is a good partner for you in the USA.
管理者のコメント;
Dear John, Congratulations on your completion of the fine “TOA130-BINO”! I am much proud of you on the splendid job. It is very interesting and exciting to see various approach that is different from mine, but as efficient as mine. I also note of your special talent of planning, too. I am also looking forward to your next plan and am always ready to assist you. Thank you for your generosity to allow me to put your name and e-mail link on this file, too. I am always welcome of your further contribution to this corner. Your friend, Tatsuro mustn’t forget to thank Mr.Joe Castoro who had kindly assisted him through his project, too.
“MOROHA” maeans “double-edged” in Japanese, and “NO” is for “of” , and “TSURUGI” is for “sword”. The order of the words is reversed in Japanese. So, the title means ” DOUBLE-EDGED SWORD”. Japanese use the term expressing contradictive resort that can bring us both the blessing and curse.
A video of EMS-BINO was submitted to “YOU TUBE” by an Italian user. I firstly welcomed the fact that the VIDEO of my EMS-BINO is being released to all over the world, and put the link on top of my website. But, stop to think of it, I thougt at the same time of the concern of MOROHA NO TSURUGI both in the field and in its contents itself. I know that there is no harm meant by the submitter, but he treats my EMS-BINO as if it were of the same level of product as the commercial binoculars. So, I withdrew the link of it on the top of my website.
High Landerには、VixenのXYスポット・ファインダーを取り付けています。これをそのままBINOに取り付る事が 可能ですが、今回は、国際光器の正立ファインダーを取り付ける予定です(納入待ち)。“正立像”で統一です。 前述した通り、実際にはファインダーが無くても導入に不自由しない程、使い勝手は良いです。
Coo is enjoying blissful days with his new keeper. He won the freedom of playing out at his leisure through his personal entrance door that was made by his kind keeper, and the warm room of the perfect shelter at a time.
Coo is enjoying blissful days with his new keeper. He won the freedom of playing out at his leisure through his personal entrance door that was made by his kind keeper, and the warm room of the perfect shelter at a time.