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Recent content by bsantini

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    Are transmission graphs relevant for you when selecting binoculars? How?

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    Are transmission graphs relevant for you when selecting binoculars? How?

    Larry Thiobos, Indiana University
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    Are transmission graphs relevant for you when selecting binoculars? How?

    For those who are interested, Indiana University conducted a research project aimed at isolating just which monochromatic wavelength is used by the himan eye when bringing an object to sharp focus. It turns out to be 572nm, which is somewhat close to the wavelength area representing the eye’s...
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    Are transmission graphs relevant for you when selecting binoculars? How?

    When discussing the human eye’s evaluation of color, do not overlook the effect of metamerism. Barry
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    Depth of Field - I am confused

    Anything in the optical train that increases contrast will increase the “apparentness” of edges, which will be visually interpreted as increases sharpness. Barry
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    An understanding of the term “Twilight Factor”

    Hi The point of the formula is to convey the (theoretical) understanding of how magnifucation can improve low-contrast detail through improved cortical processing from greater retinal mosaic involvement.
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    Optics misused Terminology.

    I think you mean "saccades" for Saltations.
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    An understanding of the term “Twilight Factor”

    I think it is very misunderstood. But theory behind it is sound. Twilight factor attempts to correlate the potentially greater light-gathering capability of larger objective sizes with the improved known contrast detail that can be realized when more of the eye’s retinal mosaic is involved from...
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    Depth Of Field better when diameter is larger?

    Regarding perceived depth of field: It will depend upon (not necessarily in order) The quality of optics in the binocular The transverse optical correction of the objective The difference in size between the observer’s pupil and the exit pupil The difference, if any, between the plant of the...
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    Depth Of Field better when diameter is larger?

    Sorry. Autocorrect Typo. I Meant to write afocal hi I really don't want to come off that way. But I do have some training and creds to back up my thinking For 28 years, I was product and sales manager for Teke Vue Optics, and a regular presenter at Stellafane. Let continue the discussion
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    Depth Of Field better when diameter is larger?

    The statement I made is fact using a focal system like a binocular or telescope. When the eye’s entrance pupil is smaller than the system's exit pupil, there is a stopping down of the aperture. But the light seen at that eye pupil size is as much as can be at that magnification.
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    Depth Of Field better when diameter is larger?

    Actually, yes. Since your eye’s pupil will routinely be smaller than a large objective’s exit pupil, your eye is, in effect, stopping down the objective in situations like these, which can help contribute to an enhanced depth of field. B
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    An understanding of the term “Twilight Factor”

    I think Twilight Factor is the most misunderstood of all the conventional calculated metrics regarding binoculars and spotting scopes. I am interested in hearing how members interpret this metric and why it is of value. Barry
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    Glasses (spectacles) with binoculars

    One should consider a bifocal (segmented) option to retain near vision utility while eliminating the progressive corridor possibility of intrusion into your viewing field and focus.
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    A unified theory: Exit pupil aberrations and Eye position, types of image blackout

    Your pupil must be centered in the exit pupil. Otherwise your eye’s smaller pupil might sample the beam (really the objective) at a point nearer it's edge, which also stops the objective down, but in an area where the objective’s F ration is fastest, and possibly most subject to showing...
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