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

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  1. B

    Swift Audubon HR/5 question

    I did this with my 12x40 Soviet binocular. Unfortunately, after a while the prisms dropped back out of alignment. Hopefully the HR/5 will be more permanent. Regards, B.
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    Aurora Borealis 10 05 24

    At very low temperatures it is dry cold and there is no moisture on the lens. At minus 34C the Kodak film broke hopelessly. I repeatedly cut new leaders but this didn't help as the film just broke into pieces. Luckily I had some Konica negative film that was fine. The camera case and strap...
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    Aurora Borealis 10 05 24

    What was the exposure and ISO? I usually used 4 seconds at f/1.2 at 200ASA or 400ASA but sometimes 1 second was enough. Often minus 20C to minus 30C or colder. Noctilucent cloud, end May till beginning August, 1 second at f/1.4 400ASA or 400 ISO. Nowadays video is so sensitive that videos are...
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    Little help with some optics anomalies

    Hi and welcome. It looks like the photo was taken through window glass or some flat glass filter or similar. Regards, B.
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    Engravings German WW1 naval binos

    Distance in metres equals 1/field in radians times total field of view of binocular in metres at the distance of the ship or known object length in metres at right angles to the viewer. The example was at 6.25km or 7,000 yards., where the best accuracy was 70 yards for the rangefinder, but...
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    Can a 25mm binocular resolve sky/cloud detail well?

    Post #13. To me this is just elitism. I spent a decade with a Nipole 7x23 micro reverse prism skeleton binocular in my twenties. It showed me everything I wanted to see. This harping about needing £3,000 binoculars is not how I see things. A good older £100 Porro shows me what I want to see...
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    Aurora Borealis 10 05 24

    Thanks Bri, I saw a similar long lasting display from southern England in the 1980s. There was a large arc in the south probably over or to the south of Paris. As well as maybe a hundred displays from Finland and a few lesser ones from England. However, the best was an all sky halo display in...
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    Nikon EII general question- Zeiss or B&L framed bino?

    Also made in 7x25 and different colours. My 5x25 is rather poorly hand painted and unfortunately opens up more than it should, so I had to mark the correct position. The typical 8x21 folding monoculars open correctly with a proper stop. Regards, B.
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    Can a 25mm binocular resolve sky/cloud detail well?

    There ae numerous micro binoculars of all sizes under many names. I have several 25mm and other sizes. These are reverse prism with prisms outside under the metal. Regards, B.
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    Aurora Borealis 10 05 24

    A beautiful coronal display. Regards, B.
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    Engravings German WW1 naval binos

    Eventually some common sense. A few points though. Although the horizon at 20m height is 16km, this is the sea horizon. If looking at a 20m high bridge of another ship the distance it is seen is double this i.e. 32km. And higher points would be seen also if the air is clear. The accuracy of...
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    Can a 25mm binocular resolve sky/cloud detail well?

    Firstly, clouds don't have detail. Except noctilucent clouds at night at 82km height, and usually 200 miles away unless a very good display when they can be very high, even overhead. June and July. Secondly, looking at sunsets is dangerous, even with a 25mm binocular. However, I did see the...
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    Engravings German WW1 naval binos

    This does, of course, assume that you are viewing at right angles to the ship. If this is not so, a correction has to be made by eye estimation. B.
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    Engravings German WW1 naval binos

    It is very simple. You estimate the number of ships that will fill the field. It can be any number. 5.5 ships is just an example. If the ship's length is known, the full field size can be estimated giving G as a known, but not very exact figure. Then E, the distance is known. B.
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    Engravings German WW1 naval binos

    Rangefinding reticles seem to go back to the 1860s. Micrometer eyepieces maybe earlier. With accurate separations and position angle. B.
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    Engravings German WW1 naval binos

    G is known. If the ship is 150m long 5.5 ships are 825 metres field size. Then E is known. B.
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    Nikon 8x30 EII - Strange Issue Inside Lens?

    Looks like balsam separation. Not fixable at an economic price. Bargains are often not. Regards, B.
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    Engravings German WW1 naval binos

    There are not two unknowns. If one is looking at a ship of known length and if 5.5 ships would fill the field, then the distance is known perhaps to 15% accuracy. I find that reticles are accurate to about 10%. There are Nato reticles, maybe 6,400. Soviet 6,000 Swedish 6,300 but now Nato. It...
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    How sharp should the view be for a Nikon Monarch M5 in 8x42?

    A warranty service may not help if the optics are at the lower end of quality control. Binoculars vary depending on how good the optics actually are, more so if Chinese. High speed polishing sometimes give poor results compared to traditional polishing. The glass blanks may also have...
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    Swift falcon 702 7x50

    If well aligned both tubes to give no eye strain, and no internal fungus or moisture $20 is good. Hopefully including delivery. Regards, B.
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    Help with vintage Binos

    Hi and welcome, I cannot see any coatings on the rear eye lenses, but possibly fine scratches. Are the reflections from the front coloured or white? What about internal reflections? Using a white light or white torch. The front may have JB or JE markings somewhere. The field of 9 degrees...
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    Manual, Objective cap for the ED78 Fieldscope

    Opticron. Or ask Nikon. Regards, B.
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    Engravings German WW1 naval binos

    G may be the whole Gross field in metres, not the size of a ship. So if 5 ships fit in the field, one can work things out. There probably isn't much distortion with these binoculars. B.
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    Appreciate Binocular Advice for Nonprofit Outdoor & Nature Program

    Thanks Canip, My bath isn't that deep. Regards, B.
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    Travel insurance for optics

    Do you also need medical cover? The national airlines usually have good cover for all items. You could also go to a trusted long established local insurance broker. There may be an exclusion for say the first £250. Personally, I would avoid anything promised on the internet. Regards, B.
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