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

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  1. tenex

    Light throughput equation

    Exactly... but what I wish is that not every manufacturer made the usual compromise! We would have much more interesting choices.
  2. tenex

    Light throughput equation

    And yet it declines, usually even worse at lower magnifications. I've often wondered why. Carry more, get less FOV?
  3. tenex

    Light throughput equation

    No, I agree with all that. The point of my question was that you had two different equations for throughput, daylight and twilight, and I wonder why you're using the latter for an overall perspective on design.
  4. tenex

    Light throughput equation

    OK, I didn't realize that was just the 8x trendline, and can now see a 10x one with shallower slope... but I'm still wondering why you're doing all this with the low-light throughput equation when that's not how binoculars are mainly used. But aren't you contending that there won't be variation...
  5. tenex

    Light throughput equation

    I am starting to think I see what I think you mean, but "predict" is an interesting word that connotes causality. Patterns alone are interesting to observe and fun to play with, but you seem to be suggesting that there's a reason why SFL 30 will have the FOV it will, involving this relationship...
  6. tenex

    Light throughput equation

    SF 42 and SF 32 have different "design/pricing strategies"? If the same glass was put in a plastic housing it would be a more impressive performer? Actually weight alone seems to predict the new SFLs. It seems odd that "throughput" would correlate so tightly with weight; I'd expect more...
  7. tenex

    Light throughput equation

    I suspect that typical Porro designs have more generous prisms (with less vignetting) and this is part of their charm, or would still be if more were made today. Do Abbe-Königs do better than Schmidt-Pechans?
  8. tenex

    Light throughput equation

    So essentially, there's so much gradual vignetting that one doesn't notice it, as in photographs with visibly darker edges around a mostly fully illuminated area.
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