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

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  1. looksharp65

    PFOV concept

    That's largely what the thread subject is about. Strange! The very same thought occurred to me yesterday! //L
  2. looksharp65

    PFOV concept

    So am I, Ed. :-O I'm not sure there's an abyss between our understandings. We may only put different emphasis on some things, then misinterpret how much emphasis the other guy puts in things. And remember I said I may be wrong. Anyway, I'll try to explain my line of thinking. Yes, and...
  3. looksharp65

    PFOV concept

    The visual acuity decreases very fast outside the 2 central degrees. Yes, there is measurable visual acuity, down to counting fingers at a certain distance. I think the use of the peripheral retina is somewhat an effect of learning how to put together a patch-work of visual cues. This means it...
  4. looksharp65

    PFOV concept

    http://www.birdforum.net/showthread.php?p=1892964#post1892964 Post #8
  5. looksharp65

    PFOV concept

    Eureka II!
  6. looksharp65

    PFOV concept

    Hm, tricky one... Your drawings show a front view towards the eye and a view from the side. Mine have only shown the view from above, where the visual field expands towards right and left. And, yeah, a cycloptic view to be correct, where no nose is in the way and left and right eye are made one...
  7. looksharp65

    PFOV concept

    Thanks Ed!
  8. looksharp65

    PFOV concept

    Back on topic with new images showing a simple experiment. This explanation of PFOV is not optical, but very much shows what happens in the visual field. The images would clearly show it, but if you want to make the experiment it only takes a paper tube and a round cardboard roundel with a...
  9. looksharp65

    PFOV concept

    AFAIK, there are only three manufacturers of organic photochromic spectacle lenses. These are Transitions, who market their brand directly to consumers although they are not making the very lenses, Hoya and Rodenstock who are optical lens factories. For silicate lenses, I only know of Schott...
  10. looksharp65

    PFOV concept

    Using binoculars with the eyecups collapsed and with no spectacles is not very convenient because the support to prevent hand-shake effects is lost, and blackouts are likely to occur. But like you write, the peripheral vision adds to the birding performance. It's easier to keep the binocular in...
  11. looksharp65

    PFOV concept

    The idea with the PFOV concept wasn't to add confusion or look for something that is not a problem to you. On the contrary, the idea is to complement the AFOV factor. I hope it's clear that I regard the 56° AFOV Fury very walk-in despite the modest AFOV. Thus, the goal is as follows: 1) To...
  12. looksharp65

    PFOV concept

    Yes, when the spectacles rest on the eyecups you have to collapse them and the PFOV expands dramatically. I think I'd prefer 1-2 mm less eye relief on the Fury because I can barely touch the eyecups with my glasses before there are black-outs, so I have to keep them in front of me with a little...
  13. looksharp65

    PFOV concept

    Thanx Steve, I think I've made the final effort and played out every aspect. Sad to say, somewhat messy explanations and repeats may obscure (!) my ability to deliver crisp and easily digestable tuition on PFOV. Oh, and there was the mother-tongue too 8-P... Anyway, I sort of feel this an...
  14. looksharp65

    PFOV concept

    Heureka! ;)
  15. looksharp65

    PFOV concept

    Please see my updates of text and image in post #30. /looksharp
  16. looksharp65

    PFOV concept

    Frank, I'm sorry, but you still don't know what I'm trying to say. The greater AFOV does NOT bear a linear to resemblance to either the PFOV or the width of the compound annulus (elkcub's terminology) The huge diameter of the Fieldscope eyepieces mean that although the AFOV is 72 degrees, the...
  17. looksharp65

    PFOV concept

    And that is what I intended it to be. Basically, your pictures seem to show the same progression. Like I wrote, one could argue that I don't show the ocular larger when it's closer to the eye. Pic #2 of mine is not a bin with a larger exit pupil, and you can see the fuzzy edges as as opposed to...
  18. looksharp65

    PFOV concept

    FrankD, now I've tried to find the differences between the two oculars you've pictured. From what I can see, the better has a less recessed ocular lens, bigger diameter ocular(?), more open periphery where the rim has a steeper angle. The ocular lens also looks larger compared to the rim than...
  19. looksharp65

    PFOV concept

    Like I wrote in the other post, the PFOV needs to be divided into two different parts. These are the AFOV and the black rim (annulus) surrounding the image, and the obscuration of the peripheral vision. This series of pictures are intended to show how the light seen after passing through the...
  20. looksharp65

    PFOV concept

    Renze, strange you should bring these pictures up here. It was only yesterday the thought of a forehead rest like that came to my mind! The eye relief of the Fury is large and if I want to take advantage of its glorious PFOV when I'm not wearing glasses, I'd need such support. //L
  21. looksharp65

    PFOV concept

    That's what we all desire! A 100° degree AFOV with virtually no rim width. Yummy!
  22. looksharp65

    PFOV concept

    Sure that ain't the porro prism housings? ;)
  23. looksharp65

    PFOV concept

    Assessing visual fields exactly without using a perimeter is nearly impossible. Doing it with a binocular in front of your eyes might be the recipe for epic fail. Anyway, I've used a visual field map to make a rough estimation what happens in the visual field in exactly that situation. The...
  24. looksharp65

    PFOV concept

    Renze, I agree that transparency is not the perfect choice of words. But that's what I read in a review of the Meostar, the reviewer used that word to describe how the binoculars nearly seemed to disappear when held in front of the eyes. Ed, I believe you agree that the physical shape of the...
  25. looksharp65

    PFOV concept

    Sending pics showing 1) The very different grip of the Zeiss FL vs the Fury 2) What my right eye can see of my index finger. Because of the extreme wide angle needed I preferred to mix two pics to one. Forget about how the eyepieces look. No doubt that the extremely sleek barrels of the...
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