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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Recent content by Gijs van Ginkel

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    Leica eye candy....

    We have investigated the 8x32 Geovid Pro and also found it to be a very good binocular/rangefinder, see our report on the WEB-site of House of Outdoor. Gijs van Ginkel
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    CZJ T3M

    To my knowledge only one prism surface of Schmidt-Pechan prisms has to be supplied with a metal mirror, since the light rays do not enter under an angle of perfect reflection on that surface leading to light losses. Abbe-König prisms do not have that problem, so no silver- or dielectric layers...
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    Vintage binos???

    sudynim, You could also look for a Swiss Kern porro, very well made and often still in good shape. Gijs van Ginkel
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    Do the owners of both Zeiss SF and Swarovski EL/NL feel they are uncomfortable for the different color cast?

    It may have escaped my attention in the discussion, but the color sensitivity of the eye can be different from person to person, but probably more important is how the color sensitivity of the human eye changes with age. Yellowing of the eye lens with increasing age is fairly common phenomenon...
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    New but probably wrong insight about lowlight

    This discussion comes back over and over . Therefore I decided to compose a large review paper entilted: "Color vision, brightness, resolution and contrast in binocular images". It is a 30 page review of published data with regard to this matter and it is published on the WEB-site of House of...
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    Habicht for birdwatching?

    Reinier, post 183, Do not try the 7x42 Habicht, it is really dangerous, since you never want to let it go after you have felt it and looked into its brilliant crystal clear images. Gijs van Ginkel
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    Usable Eye Relief (spartan method)

    Maljuno, post 7, On November 3, 2023 Groningen University celebrated the 75-th anniversary of the Nobel Prize of Prof. Zernike, which he received in 1953 for the development of phase contrast microscopy. It was celebrated by an international symposium during which also a lecture was dedicated to...
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    Usable Eye Relief (spartan method)

    Canip, post 5, I did understand from your previous posts what you are measuring and how you are measuring it, but the producers publish the eyerelief the way I described it and technically that is in my view correct. I would describe your method as practical eyerelief, since you take into...
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    Usable Eye Relief (spartan method)

    Canip post 2, For our measurements of eye relief, I use a Ramsden dynameter (designed and made by the Netherlands optical company Bleeker, the optical engineer who has worked for that company later became head of the optical workshop of the Utrecht Universities workshop and I received it from...
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    Carl Zeiss Jena DF 7x50 Extremly early model?

    As far as I can see it is a Zeiss DF 7x50 from 1915, 1160 g, FOV 128m/1000m, From 1919 called Binoctar and made until 1945. Gijs van Ginkel
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    Trinovid hype

    Ignatius, post 29, I suppose you also have Hans Seegers book from 1989 "Feldstecher. Ferngläaser im Wandel der Zeit". Very useful source of information. Gijs van Ginkel
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    Trinovid hype

    Ignatius, post 27, No it was published for the occasion of the celebration of the 100th anniversary of binocular production of Leica and the number of booklets made seems to be limited. Gijs van Ginkel
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    Trinovid hype

    Ignatius, post 25, In 2007 Gary Hawkins published a booklet "Novelties. The story of the Leica Trinovid". It gives very useful information about production numbers and production years of the different Leica Trinovid binoculars in the passed years. I do not know if it is still available, I...
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    Trinovid hype

    In addition to my previous post I report the data from our investigations of 7x35 Trinovids from different production years (the whole report can be found on the WEB-site of House of Outdoor). Trinovid 7x35B (1966) transmission values : 500nm=49%, 550 nm=57% Trinovid 7x35B (1982) transmission...
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    Trinovid hype

    Thotmosis, post 19, Your Leica Trinovid 7x35B is from around 1981 (Gary Hawkins list from 2007) and is in no way comparable with the 7x35 Retrovid from 2023 as far as transmission and image brilliance is concerned. Gijs van Ginkel
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