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

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  1. J

    What purpose does this have?

    Hi All, I came across this on an old velbon tripod. What purpose does it have, a spacer? What are the two screws for? Many thanks John
  2. J

    ED glass in old opticron.

    Hi I acquired this scope second hand.After reading some posts on here was wondering is this the original ES scope with ED glass? Thanks for your help John
  3. J

    How are waterproof porro Binoculars possible?

    How does this design work. Is there an internal focussing lens that moves? Does it impair image brightness? Thanks John
  4. J

    More contrast with ED scopes?

    If two spotting scopes have identical specifications but one is ED, does the ED scope have better contrast? I understand what ED glass does regarding chromatic aberration, but was wondering if it effects contrast as well and if so how. Many thanks John
  5. J

    Opticron SDL zoom

    Hi could anyone tell me how this compares to the HDF zoom? Does it have a wider FOV. Can't find FOV specs anywhere! Thanks John
  6. J

    5 elements in a spotting scope?

    The primary of my Opticron 66ED has five elements. My astro 72ed only two. There both wonderful instruments, but why five elements? Thanks John
  7. J

    Kowa 884

    What is the prism arrangement for this scope. Can a straight through scope like this use a roof prism? Thanks John
  8. J

    Caterpillar alive still?

    I came across a small still living Caterpillar beneath a bird's fresh dropping on my car? Any explanation? PS enjoy your dinner.
  9. J

    Prism size in spotting scopes.

    Dear All, When reading spotting scope reviews I often read that spotting scopes with large prisms help image quality. Can anyone explain why this is? Many thanks in advance. John
  10. J

    Focal Ratio /F Number of Spotting scopes influence on focus depth.

    From a photography point of view I understand how it works. However I thought the 'f number ' of a spotting scope had no influence on focus depth/depth of field. However my 'f 3' hummingbird 50ED had a very shallow dof, so does the f number influence depth of focus after all? Thanks for your...
  11. J

    Minimum focus distance.

    Hi, Does anyone know what effects the minimum focus distance in a spotting scope. I was looking at two spotting scopes with same specs. However the straight through spotting scope had a greater minimum focus distance than the angled one. Why is that? Thanks John
  12. J

    Different prism design spotting scopes.

    Hi, As Im looking for a new scope Ive started thinking more about their prism layout. I've noticed a lot of Kowa scopes have the eyepiece offset to one side, while others don't. I know many scopes use amici style roof prisms, by I thought the porro design was the same for all. Is the attached...
  13. J

    Waterproof eyepieces?

    I was pretty surprised to discover opticron HDF eyepieces are not waterproof? Are the standard zoom waterproof? I then couldn't find out if Kowa long eye relief/wide angle eyepieces were waterproof? Is this common in the birding world and is it a problem? And if so, what is the solution? Im sure...
  14. J

    Spotting Space

    Hi fellow birders. The other night I couldn't be bothered setting up my astro refractor, so instead had a look with my hummingbird 50ED and a 18mm astro eyepiece. Magnification only about 10x FOV 5-6 degrees. I was pleasantly surprised how good the views were. I also spotted quite a lot of...
  15. J

    A Willow Warbler that thinks it is a blue-tit.

    Hi All, Have been watching some interesting behaviour in my garden and the surrounding gardens. A Willow Warbler is always in company of a large flock of blue-tits and long tailed tits. However if any other bird joins the party, the Willow Warbler is very aggressive at driving the bird away...
  16. J

    Small straight through spotting scope for monopod.

    Hi All, I very much enjoy using my opticron IS60, straight through scope on a monopod. Very lightweight and portable. However after purchasing a 80mm ED spotting scope I'm looking for a similarly lightweight upgrade. is this possible, or will Ed glass always be heavier? thanks in advance John
  17. J

    Goshawks in Scotland

    Hi My favourite bird is the Goshawk. However I have only ever seen it twice in Scotland. Another time I thought I saw one in Corstorphine hill in Edinburgh? A winter migrant? Does anyone have any information or tips for seeing more of this magnificent bird. Thanks John
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