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.
カテゴリー: BINO Progress Report / 製作状況速報
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For the benefit of the EMS-BINO planners, I will show the anatomy of the “light path” of the EMS-UL. The total light path of the EMS consists of three parts.
Path “A” is the distance from the bottom of the barrel to the first reflection point, that is 2 + 18 = 20mm.Path “B” is the distance from the first reflection point to the second one, that is 18+2+12+2+18 =52mm.Path “C” is the distance form the second relfection point to the top surface of the 2-inch sleeve, that is 18 + 2 + 58 = 78mm. So, the total light path is A + B + C = 20 + 52 + 78 =150mm. *The light path of EMS-UL is shortened by 2mm on July 21,2017. Now, the correct light path of the standard EMS-UL is 148mm.(2018,11/05)
Helicoid tubes and IPD-Crayford tubes, each has its merit and I have chosen one of them in the cases.
The main problems of the commercial helicoid tubes for camera parts are the lack of enough rididity and the end shape that needs to be processed to connect to other telescopic parts.
Now, I have successfully developed this new helicoid perfectly speciallized for binoscopic use.I can definitly say that it is more riｇid than any other commercial helicoid tubes planned for camera parts.This is designed for the heavy use of binoscope back that will hold EMS and heavy oculars at a time.Both ends are tapered boss that will fit into the 50.8mm standard sleeves. This means it is easily used reversible on left or right EMS for the ergonomical hand operations.
2. Of course, you should take off the sleeve and the filter to access the second mirror.
3.and 4. If you don’t want to take the barrel off, you should at least unscrew off the entrance aperture. You need not a special tool to do it. You have only to hook your fingers to unscrew the aperture. When it is too tight to unscrew, you can use rubber sheet or something to protect your finger.
5. Then soak the tisse paper in the absolute ethanol.
6. Don’t save on the paper. Never wipe more than one stroke. You should dispose the paper in each stroke. Of course, when you see any dust on the mirror, you should blow off the dust in advance of wiping.
But, you don’t have to be too nervous of hurting the mirror as long as the tissue paper is wet and new. The mirror surface has enough durability in wet-wiping because it is dielectlic over coated on the silver coatings.
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.
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.
Finished EMS-Binoscopes are free from the original adjustment, because they are carefully adjusted by Matsumoto before shipping. Especially those who had accepted the binoscope at my shop have proved that EMS-BINO will have no collimation problem by the vibration of the family car while carrying.
Still, however, some of them have shown collimation problem by shipping. And in such a case, users should recover the collimation by themselves if you cannot afford to bring your troubled binoscope to my place. So, I reccommend you to carefully study at my website to master how to adjust the disordered binoscopes.
Assume that the left 500yen coin is the image of the left telescope. In condition that the XY image adjuster has not lost the original position, I can judge the objective end of the right telescope is misalined in the left-down direction. In other wotds, you have only to pan the right scope in the same direction as the right 500yen coin.
This is the merged image by the above adjustment. You will still find something odd in the above image. Yes, the left 500yen coin leans to the left, and the rihgt one to the right. In other words, the left and right image of the vertical lines form the “V” shape. So, I call this tendency of the error “V error”. And the counterpart error I call is “/I”(lambda) error. Now, you know that collimation is one thing, and image inclination is quite another.
1.Unscrew the three yellow arrowed set-screw, and the connection of the two units of the EMS is released, and you can rotate the units with each other. Take the most care when you unscrew the last screw so that the eye side units that is slightly blued will not rapidly drop down.
2.Rotate the whole blued part quite a bit in the same direction of that you want to rotate the image. Red arrow shows the rotating direction to correct the inclined image shown at this sample.
3.Of course, you should reversely do the same adjstment on the opposite scope. Don’t forget to screw the set-screws after finishing the adjustment, too.
The photo is the customized EMS-L for the binocular use.
Put the EMS on the right-angle gauge. (A desktop and a wall can be a substitute.) You see the eye-side surface doesn’t touch the wall closely.(red arrow)
Then,unscrew the three set-screws (blue arrow in the photo) and fix the connecting angle untill the both sides of the EMS will touch the floor and the wall.
(The place of the three set-screws are different from the types of the EMS. Please consult me when you cannot identify the screws.)
This photo is the finished stage of the upper adjustment.
Note the both sides of the EMS closely touch the gauge surfaces. At this stage, the image-inclination adjustment is almost perfect.
Even if some image-inclination should exist at this stage, You can adjust the image angle up to perfect by subtlely adjusting the viewing angle, for example, to shift the right angle toward 89dig. or 91dig.
This is one of the excellent features of the EMS.
Though the above adjusment is done by me, and the users will not have to do that by themselves, I explained that because I would like you to learn one of the remarkable features of the EMS.
This is the diagram drawn to explain how the images rotate in accordance with the change of the viewing angle referred above.
“A” positon is that of the right angled, “C “position of the straight viewing.
If you were to correct the trouble in the photo only by turning the component telescopes, which do you think is the right prescription?
A: Turn the left telescope a bit to the upper left, or the right telescope to the lower right.
B: Turn the left telescope a bit to the lower right, or the right telescope to the upper left.
( 2 )
Which do you think is right?
A: The inter ocular distance is incorrect.
B: Collimation is not correct.
C: Both A and B can be an answer, we cannot tell which is right in the photo.
( 3 )
Which do you think is right?
A: It’s not a trouble of collimation, but only the inter ocular distance is far too wide.
B: Collimation is incorrect. Turning the two telescopes to the converging way is one of the remedy.
C: Collimation is incorrect. Turning the two telescopes to the diverging way is one of the remedy.
( 4 )
Looking at the Jupiter, the further the satellite the wider the separation occurred while the Jupiter itself was merged. Which do you think is the most appropriate prescription? Winking the eyes, the lower of the left end satellite was proved to be the image of the left telescope.
A: The angles of the mirrors of the EMS seems to be in disorder so complicatedly that it would be better to leave it to Mr. Matsumoto.
B: To change the viewing angle of the EMS slightly to the 91degrees’ direction, keeping the eyepiece barrels parallely, will be a perfect remedy.
C: To change the viewing angle of the EMS slightly to the 89degrees’ direction, keeping the eyepiece barrels parallely, will be a perfect remedy.