[keltos01]

LOL yes too easy

It won't work that way as intended...

You need to be precise for the scale to work as conceived.

The vertical scale is a means of easily getting distance thanks to simple calculations. Each small mark is not one degree, but approximately 0.6 degrees. Why? Because that is close enough to a radian and allows stadiametric rangefinding if you know or can estimate the target's heigth.

A quick example: Looking through the periscope of the Kaiten you see a destroyer whose mast reaches the "10" mark in low power magnification. How far is she?

Asuming a 25 metres mast (A good average for destroyers) you do following maths:

25 metres (mast ) x 100 (The scale "constant" value)= 2500

2500 / 10 (heigth the mast reaches in the scope scale) = 250 metres

The destroyer is 250 metres away.

The same example, but the destroyer is reaching only the "5" in the scale:

25 metres (mast ) x 100 (The scale "constant" value) = 2500

25000 / 5 (heigth the mast reaches in the scope scale) = 500 metres

Got it now?

I created my german periscope reticles for SH3 and SH4 using that same principle, adjusting the marks to the proper size, so I could use them to calculate distance as they were intended. It would be a crime to do all the research job you have completed, and now leave the scale inaccurate.
I agree completely
I will send you a finished scale in a moment, stay tuned. I will just modify my current german one and you are ready to go.

do you mean you are actually gonna make that reticle for us at the Japanese Campaign mod ?


As I told the guys at RFB, our aim is to be as precise as possible in what we do, so far all our models and changes have paved the way to a Real I-Boat mod.

I would truly appreciate if you could help in that way then.

do you need the stuff I drew in autocad or are the here posted pictures good enough ?

keltos




additionnal intel :

iii) Periscopes and Lens Coatings

Added to the company's accomplishments in rangefinder production were similar successes made in the field of periscope manufacturing. Nippon Kogaku's first periscope was produced in 1918, and had an overall length of seven metres.49Following the First World War, the company began to produce periscopes based upon German designs, manufacturing between 50 and 60 units between 1920 and 1922.50By the mid 1920s, German technicians were hired by the company to aid in the development of new models, and records indicate that by the beginning of the Showa period, large numbers of 9-metre and 10-metre periscopes were being produced.51Added to these models, which were featured aboard most first and second-class IJN submarines, was a series of smaller periscopes for use aboard the navy's controversial midget submarines. The questionable effectiveness of these one to five-man submersibles notwithstanding, Nippon Kogaku was called upon to make working periscopes for the over 300 units that were produced across their various classes.52






Added to the optical engineering of the periscopes themselves was an ongoing effort made by Nippon Kogaku to increase the transparency of their glass surfaces. The standard 10-metre periscope produced by the company featured 33 individual optical elements and its complexity resulted in dramatic light losses.53In the interest of maintaining their strategic advantage, Japanese submarine commanders wished to use their periscopes at dawn and in the low light of early evening, but the initial inferiority of the optics prevented them from doing so without difficulty. These commanders placed great pressure on the navy and on Nippon Kogaku to improve the performance of their periscopes under low light conditions, and the company responded by initiating research into new lens coating techniques aimed at increasing their transparency. According to the investigators in the U.S. Navy technical mission:

…two methods were found for 'coating' glass surfaces:

1. The chemical method, in which the glass was treated with nitric acid.
2. The evaporation method, in which cryolite is evaporated and deposited upon the glass surface, in vacuum. After treatment, the glass is baked at 150°C for one hour for durability.54

These procedures were evidently conducted at the Nippon Kogaku's optical factory at Yokosuka, in coordination with the navy's submarine base at Nagaura Harbour. During their analysis of the plant, the U.S. Navy investigators noted: 'Evidence was found that lens coatings had been carried on' and recorded that 'a few samples of apparently experimental coatings and coating material were obtained.'55Such experimental work demonstrated the kinds of subsidiary technologies generated by the company's efforts to deliver on IJN optical contracts. As engineers sought new ways to solve these kinds of design problems, a host of secondary investigations was inevitably added to their ongoing studies in the field of glass production. These new tasks included: experimental methods of glass annealing, the four-stage grinding and polishing of both lenses and prisms, and a variety of efforts to enhance night viewing with the aid of lens coatings and filters.56The company's efforts in the field of experimental periscope lens coatings would be of particular importance in the postwar period as such coatings were later found to have a variety of optical applications. Periscope production too continued after the war, and Nikon manufactured instruments for construction surveying, as well as a series of 10 metre periscopes for use in the railcar maintenance bays of the shinkansen, or bullet-train railway line.57

periscopes diagrams :

type 3 periscope :


By keltos01 at 2009-03-09



Kaiten periscope :


By keltos01 at 2009-03-09


http://www.fischer-tropsch.org/prima...ort%20X-05.pdf