Congress of Japan Clinical Ophthalmology
I investigated the lens of the Nikon Ophthalmic Camera AS-1 in more detail. I'm not familiar with medical equipments, so I consulted with an expert. My friend Dr. John Doe showed me some academic paper on medicine. They are all 40-year-old academic journals from the late 1970s to the 1980s. I have listed it as a reference at the end of the article.
The following figure is taken from Vol. 33, No. 5 (May 1979) of the journal "Clinical Ophthalmology" of the Congress of Japan Clinical Ophthalmology. The title of the academic paper is "Clinical application of high-resolution slitlamp photography. Report I. Design and data of the prototype apparatus ". Several medical photographs taken with the Nikon Ophthalmic Camera AS-1 are described. Haruo Oda, one of the authors of the paper, is an engineer at Nippon Kogaku K. K. . Refer to the reference 1.
Copyright (c) 1979, Nippon Kogaku K.K. All Rights Reserved.
Objective Lens Construction
I will show you the lens construction diagram of the two objective lenses special designed to Nikon Ophthalmic Camera AS-1.
5x Objective Lens Construction
The 5x objective lens consists of 7 elements in 5 groups. The 10x objective lens consists of 11 elements in 6 groups. They are as gorgeous as the objective lenses of the finest microscopes.
10x Objective Lens Construction
Resolution Power of Lenses
A table entitled "Objective Lens Specifications" was published in Reference 5, 1985, Journal of the Japanese Society of Ophthalmological Optics 6 (1), page 85, and is quoted below. The resolution power of the 10x objective lens is 800 lines/mm, which is an amazing performance. You should note that the special designed zoom lens is listed.
Objective Lens Specifications
Nikon Ophthalmic Camera AS-1 Advertising
The advertisement is quoted from the following journal of the Japanese Ophthalmological Society.
In the 1979 advertisement, there were two objective lenses, 5x and 10x.
Left : 1979
Right : 1981
Nikon Ophthalmic Camera AS-2
Reference 5, 1985 Journal of the Japanese Society of Ophthalmological Optics 6 (1) page 85-88 publish a paper entitled "Experimental Use of New Ophthalmic Camera (Nikon AS-2)".
There is little information about the Nikon Ophthalmic Camera AS-2.
That information is not published in Nikon's 75-year and 100-year history book.
Of note in this photo is the mounted lens. Looks like a normal AI Nikkor lens. However, this is a very rare special designed zoom lens. The lens barrel is engraved with 1.5X, 2X, 2.5X, and 3X, which indicate the zoom ratio. The aperture ring is engraved from F4 to F32 like a normal AI Nikkor lens.
Nikon Ophthalmic Camera AS-2
Since it is a very rare and valuable image, I quoted the photograph of Nikon Ophthalmic Camera AS-2 from the academic paper in Reference 5.
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Copyright Michio Akiyama, Tokyo Japan 2020