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

NEW Terra ED 32mm Under Armour Edition Binocular (1 Viewer)

To pick up where the discussion left off, has anyone encountered yellow ghosts above dark objects with TED 8x32s in the circumstances @cesar describes in the previous post? Just recently purchased a pair new---in part based on reviews and commentary here---and whilst I've not had veiling glare I have found these conditions can cause certain species to sprout second heads. For example, a western grebe renders with a normal looking head plus a yellow ghost matching the black plumage appearing above the bird's actual head. A snow goose (white plumage) in literally the same spot and lighting is unaffected. The same effect occurs with other dark plumage, such as a yellow halo above a coot's body and head. This affects both optics, being visible with both eyes, just the left eye, or just the right. It clears off if the bird moves 15 or 20 degrees away from the sun.

In several decades of peering through various optics I've not encountered anything like this, so curious if this is normal behaviour for Zeiss's optical formula or if my pair's somehow managed to have something consistently out of whack. Aside from the objective caps popping off at the slightest provocation they seem otherwise fine; as other reviewers have noted good quality for a midrange optic, albeit with a tendency to a yellow cast, and pleasant focus action and eye cups. So my guess would be the ghosting is expected behaviour. However, I can't find anyone else mentioning it.
 
To pick up where the discussion left off, has anyone encountered yellow ghosts above dark objects with TED 8x32s in the circumstances @cesar describes in the previous post? Just recently purchased a pair new---in part based on reviews and commentary here---and whilst I've not had veiling glare I have found these conditions can cause certain species to sprout second heads. For example, a western grebe renders with a normal looking head plus a yellow ghost matching the black plumage appearing above the bird's actual head. A snow goose (white plumage) in literally the same spot and lighting is unaffected. The same effect occurs with other dark plumage, such as a yellow halo above a coot's body and head. This affects both optics, being visible with both eyes, just the left eye, or just the right. It clears off if the bird moves 15 or 20 degrees away from the sun.

In several decades of peering through various optics I've not encountered anything like this, so curious if this is normal behaviour for Zeiss's optical formula or if my pair's somehow managed to have something consistently out of whack. Aside from the objective caps popping off at the slightest provocation they seem otherwise fine; as other reviewers have noted good quality for a midrange optic, albeit with a tendency to a yellow cast, and pleasant focus action and eye cups. So my guess would be the ghosting is expected behaviour. However, I can't find anyone else mentioning it.


Are you sure this isn't CA? It can appear quite brightly [as yellow or orange to my eye] along the top edge of objects in view, and the Terra is not well corrected for this.
 
It's an order of magnitude larger than any CA fringe I've ever seen, even in chromatic (i.e. not particularly intended to be achromat) optics, and many times wider than the yellow fringing the 8x32 TEDs sometimes exhibit on dark objects at larger angles from the sun. More like a second pupil develops that's somehow an optical inverse in the sense a dark area gets duplicated as a bright area. Though it might perhaps be better to term it revealing glare as opposed to veiling glare as dark areas are accurately reconstructed in yellow. Unfortunately conditions haven't been such it's occurred when I've been equipped to try to digiscope the TEDs.

As the colour and object attachment are similar it's plausible the same essential mechanism could produce both behaviours. However, CA in the sense I've encountered the term is isotropic (fringing can occur along all sides of an object) whereas this effect seems to occur only in the upwards direction. It doesn't seem to shift in position as binocular orientation changes in respect to the sun, so could be down to an incompletely absorbed internal reflection from a Schimdt-Pechan surface or something similar.
 
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