Subjekt: Marox 8x32
From: l.helling@___ne.de (Lothar Helling)
The plastic knob on top of the central hinge works very well as a stay at the forehead. The binocular than is more stable. I don´t know if this is the original funktion. The dealer I bought my Marox said so. However - it works.
Best regards, Lothar
Subject: Moeller Wedel Marox
From: "Frederick Schwartzman" <jurisfred@___bal.net>
Dear Guus: I have the same Marox and I too have wondered about the function of that center knob. I note that the knob turns up and down but nothing happens. It does not tighten or lock the interpupillary setting and has nothing to do with focus. The only thing I could think of was that it might be a rest or brace against the bridge between the eyes and the raising and lowering function would accommodate different facial configurations. However, I cannot really believe that that was the function. Please let me know if you receive any additional information on the subject.
Subject: Exit Pupil Diameter and Sharpness
From: "Tim Stevens" <stevptm@___ink.net>
In Binocular List #273, Kenny started a dialog on the subject of the relationship between exit pupil diameter and "sharpness". In #275 and #277, Rafael and William Cook responded, and in #278 Kenny replied.
All this discussion related to the relationship between exit pupil and sharpness stimulated me to study two texts (the Handbook of Optics and Smith's Modern Optical Engineering) to see what I could figure out about this subject. I concluded that if the optics are perfect, the exit pupil needs to be 4mm and that if the optics are corrected to the Rayleigh Quarter Wave Limit, then the exit pupil needs to be 5mm. There is just not enough space available here to explain how I arrived at these numbers and (just as important) what assumptions I used to arrive at these numbers. However, if you e-mail me at stevptm@___ink.net, I will be happy to e-mail you my detailed analysis (1.4 MB due to embedded graphics). If you want a hard copy, then e-mail me your mail address and I will mail you a hard copy of my analysis.
Tim Stevens "binonut"
Subject: Fuji UBMM, collimators
Why don't you make one, following Hanna in ATM books.? After a tree grew, I lost my infinity target for an otherwise Navy style setup. I have sketched over a dozen setups using mirrors, but have not yet built one. Tilted spherical mirrors give good enough images for projection systems. I saw one in Hinkle's (OMC ret. ) basement in Pasadena. He used it on "hundreds" of Bushnells in 1950's or '60's subcontract work. He got tired of the Navy collimators when at the U.S. shipyard in Boston. Do not know if he ever used the Mk. 13. which has limited aperture anyway.