跳到主要內容

BR optics

 from Canon, Blue spectrum refractive optics


BR optics is based on a new organic optical material, developed by reexamining lens material from its molecular structure. This new lens material features unique anomalous dispersion characteristics that are capable of greatly refracting blue light (short wavelengths spectrum), which has traditionally been difficult to focus on a single point. Incorporation of a BR lens, consisting of BR optics sandwiched between concave and convex glass lenses, makes it possible to control the path of blue light (short wavelength spectrum), producing clear, sharp images by thoroughly reducing chromatic aberration.

Nikon also introduced Nikkor z 400mm f/4.5 VR S telephoto lens with SR lens:

The lens is constructed of 19 elements in 13 groups, including one Extra-low Dispersion (ED) element, two Super ED elements and one Short-wavelength Refractive (SR) lens element. The SR element refracts blue light more than green or red, helping to control longitudinal aberrations...

Nikon patent: WO2020217791A1 

dpreview

The so-called short wavelength refractive (SR) glass., from hikari

70-200mm uses: J-SFH4 nd：1.663820 vd：27.35

120-300mm uses: J-SFH5 nd：1.755750 vd：24.71

from R.A.Buchroeder,  Arizona U,

it is related to GLAPO(Glass-Liquid Apochromatic objective), patent 5731907, auxillary lens with liquid element for correcting secondary color



...substantially abnormal dispersion liquid being selected to produce a substantially zero focal length change in the achromatic optical system over a wavelength band of approximately 0.43 micron to 0.61 micron

material of dispersion liquid: CARGILLE 642134 

another example: 

Larson 3.8 m f/1.2 with GLAPO, using another exotic liquid Cargille 550203


 

標籤：

留言

張貼留言

這個網誌中的熱門文章

CMOS sensor trends and astrophotography, from amateur astronomers perspective

Nowadays, even in low light conditions, digital camera can quality pictures with higher ISO, noise and hot pixels have been gradually reduced. Sony has introduced back illumination process for consumer market. Sony BSI sensors evolved  from Exmor to now Exmor RS( stacked) technology. This stacked technology allows further chip size reduction, which has strong demands in smartphone camera market. Digital astrophotography is also benefited from such advances, utilising Back Side Illumination technology Exmor: Within the CMOS sensor, it outputs low-noise digital signals by "on-chip column AD conversion" and "dual noise reduction" to suppress noise in the first half of the process In low light conditions, when a wide aperture is desirable to collect as much light as possible. At apertures wider than f/2.0, back-illuminated Exmor R sensors are significantly more efficient at collecting light than conventional, front-illuminated sensor...
張貼留言
閱讀完整內容

ultrafast rendezvous to ISS

    14 Oct 2020,  being the first to use a new “ultrafast” rendezvous” scheme with the ISS. Following a flawless ascent to the correct orbit, Soyuz 2 .1a , Soyuz MS-17 caught up with the orbiting laboratory in only two orbits (three hours), halving the time it takes for crew to get to the Station.   The three space travelers of the Soyuz MS-17 mission launched on a six-month mission the International Space Station.  previous 3/4 orbit rendezvous: Soyuz MS-16 4 orbit rendezvous A three-orbit profile was deemed possible without major flight design changes after inauguration of the Soyuz 2-1A rocket that provides a much higher orbit injection accuracy than its predecessors and would allow the two correction maneuvers on Orbit #2 to be eliminated while the Automated Rendezvous Phase would still remain untouched. The deletion of the Orbit #2 maneuvers was expected to slightly tighten the already restrictive phase angle window from and upper limit of 30-35° to 25-28°...
張貼留言
閱讀完整內容

Scythians 斯泰基 塞種 西古提人

900 BC - 200 AD British museum   Tomb of scythe prince, Buktarma valley, 1200 masl, Google map Herodotus   絲路上的帝國 Biblegeography   哥羅西書 3：11  在此並不分希利尼人、猶太人、受割禮的、未受割禮的、化外人、 西古提人 、為奴的、自主的．惟有基督是包括一切、又住在各人之內。 塞種 塞迦  saka 史記漢書 西域傳： 塞種  ctext 昔匈奴破大月氏，大月氏西君大夏，而塞王南君罽賓。塞種分散，往往為數國。自疏勒以西北，休循、捐毒之屬，皆故 塞種 也。 匈奴列傳 Ctext ：塞王 《史記》在《大宛列傳》與《匈奴列傳》中， 詳細 記錄了中亞至天山一帶的塞種（塞王、塞地）狀況。例如，文中記載了月氏西破走塞王，導致塞人南遷越過懸度（今帕米爾高原及克什米爾一帶） Baike Genetic history   Genetics  Nih griffin  ? Scytho-Siberian  world 塞迦 saka  wiki Disappeared? Sarmatians （ 薩爾馬泰 ， 奄蔡 史記 ,  Aorsi ）and goths YouTube  
張貼留言
閱讀完整內容