The usual problem with "best" lists is that they are not including any sort of "requirements" ...
Re-stated ... for me .. the "best" widget ... is the one that meets the requirements at the lowest cost (since why spend more if your requirements are met at a lower cost).
So unfortunately, I don't think it is as simple as a "best" list.
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I do get a lot of people showing up on other forums thinking they might want a thermal clipon ... and it might be worth having a sticky that explains the pro and con of thermal clipons ... but of course, do people read stickies ??
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I also have several BAE OASYS cored devices (of which the TEO devices are included) and they do have a lot of "shock and awe" to the image ... mostly because of the rendering of the terrain. But do they even have "the best" image in all conditions? (best image to me meaning I can ID the critter, faster and a greater distance) ... I'm not sure about that. The Zeus Standard 3x, 75mm 640(30) I had .. had an extremely clear image and could see a single hand warmer at 500yds and the ir-hunter could not on one night. This was during pasture burning season and a lot of smoke was in the air between me with the thermals and the handwarmer on the target.
So also saying the "best image" is not a linear construct at least not in all conditions. The cores, the lenses, the displays all matter, but so does the software ... and the OASYS software might be trying to optimize some aspects of the image whereas the FLIR software might be trying to optimize other aspects.
In great thermal conditions like I had last night (after a day of sun seemed to dry everything out and evaporate some of the water in the air ... the thermal conditions were fantastic ... but for the prior week, misty rainy every hour of every day ... the critters have been floating in a sea of grey ... and no thermal is great in those conditions ... I could still see the critters but not the terrain ... trees only "detectable" when a critter passed behind one relative to me. I couldn't even see buildings beyond about 50yds and then just barely. The worst thermal conditions I've seen. And my POS ATN ODIN was doing as well as the Mk3 35mm in those conditions.
But seeing beautiful terrain with the thermal is not a primary requirement for me. Being able to ID the critters faster at a greater distance is. And being able to do that at the lowest cost is. So bottom line ... my "best" list might be different from yours ...
What about a "good enough for hunting hogs" list ... would that be different ?