EMS Binoscope by Takahashi FS60 telescope

This little binoscope is light in weight and small in size which makes it very transportable and usefull for quick observations. The basis is a set of FS60-CB telescopes with 2″ attachment. They were converted with a CSV tube to obtain 22 mm more backfocus. A set of 2″ EMS-UL was used to allow maximum field with minimum backfocus. Together with the new special EWV-adaptor, instead of the eyepiece barrel, backfocus is reduced another 18 mm. The EWV-32 mm eyepiece can now be used to obtain a magnificent 7.7 degree field at 11x power.

To have IPD adjustment the FS60 telesopes are mounted on double Lineair Translation Stage and Track from Edmund Scientific which fits very convenient to the mounting plate of a standard Vixen Forkmount. With the EMS 1-1/4″ adaptor Pentax SMC eyepieces are Parfocal with the EWV-32mm eyepiece. When a 3.5 mm Pentax SMC eyepiece is used with the FS60-EMS binoscope it shows crisp binoviews of Jupiter and the Moon at a stunning 101x power.


Since the CSV tube is not available anymore I guess it should be possible to obain enough backfocus for the EMV 32 mm eyepiece with a shorter version of the EWV-adaptor.

Alexander van Lemel
Rijssen, Netherlands
September 28, 2010

Comment by Matsumoto/ 管理者のコメント

Mr. Alexnander van Lemel has made his second binoscope, FS60-BINO, successfully after making his first one of TSA102-BINO

I would like to give him a biggest applause on his feat of building two binoscopes using my EMS, conquring the limitted information, and especially the language barrier. The only communicative language tool was English which was foreign language for each other.

I am also very appreciative of his generousity for allowing his full name and the link of his e-mail address appearing on his article. That will greatly help foreign guys especially in Netherlands who have the aspiration to build binoscopes someday.

 オランダの Lemel 氏のTSA102-BINO(未発表)に続く第二作の、FS60-BINOです。 都合により、短筒仕様の鏡筒の入手を諦め、通常鏡筒を工夫して合焦の問題をクリヤーしています。  少し前にBINO製作情報速報にて、EWV32㎜のマイナスプロファイル化をご紹介したのは、この方の 注文でした。この改造EWV32㎜はEMSの短いタイプの31.7AD(EMS-S,M) 用のアダプター;高さ44㎜)と同焦点になっていますので、EMSフルシステムでの光路長は、EMS-S等に対して、わずか14㎜の追加で済んでいます。