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

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  1. T

    Dioptre Setting: Fallacy and Fact

    Bill, For the human eye there is no practical difference between "across the street" and infinity. Most eye doctors measure at 20 ft or 6 m and that is a difference to infinity of less than 0,2 dioptres. Viewed through a telescope or binocular though, you would have to multiply that difference...
  2. T

    Dioptre Setting: Fallacy and Fact

    When someone describes their own post as "inspirational" I raise an eyebrow. And I don't think the PhD could have had anything to do with optics ;)!
  3. T

    Dioptre Setting: Fallacy and Fact

    No objections to an extensive discussion, but it surprises me too. My original post was merely intended to remove a widely held misconception on dioptre setting. To set the dioptre, which is simply a device to adjust the focus independently on the right barrel, whether on the right eyepiece or...
  4. T

    Dioptre Setting: Fallacy and Fact

    Lee, I agree that glasses wearers should also check the dioptre setting as one cannot automatically assume that the focus on both barrels is identical at the zero dioptre setting. Other discussions here have centred on dioptre shift as a consequence of an imprecise internal focussing mechanism...
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    Dioptre Setting: Fallacy and Fact

    Exactly, but there seem to be many who believe otherwise. John
  6. T

    Dioptre Setting: Fallacy and Fact

    There are frequent misunderstandings and misconceptions on dioptre setting and many are of the opinion that the dioptre should be set on an object at or near infinity. Conversely, would they expect the dioptre setting to be wrong for objects at shorter distances? On another thread I asserted...
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