264win
... How do thermal rifle scopes vs scanners compare with "field of view" so to speak ? ...
thermal optics generally have "FOV" in their spec data, so you can see the FOV for each device. Usually shown in "degrees" and "feet" at 100yds or "meters" at 100 meters, or some close variation.
Generally ,the more magnification, the less the FOV and vice versa, the less the magnification the more the FOV.
There are scanners with plenty of magnification and thermal scopes also and some with no magnification. So about 1x up to about 5x, though there is at least one case of 8x that I can think of off the top of my head.
So as far as FOV, it isn't so much scanners versus scopes, but more magnification versus FOV.
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is it possible to have a thermal rifle scope that could attach via a QD system, so it could be detached and used to scan and reattached for shooting
I'd say any scope with a QD could be used this way. I've done this myself with an Apollo (I was using the Apollo as a 1x scope). I used a Larue rail clip on the top rail, so I could remount quickly by feel alone to exactly the same rail position and I practiced it 100+ times (without looking). You will get perhaps a 1 inch POI shift per 100 yds on any given remount. But one of the key variables is the human remount factor, so by practicing 100 times, you can reduce the impact of that variable.
Short answer it can be done, but the "return to zero" is not likely to be 100% perfect. If hunting a large enough critter, like a hog at a close enough distance, like inside 100yds, it won't matter.
I had a lanyard on the Apollo at all times. That way, when I pulled it off the gun, I could slip the lanyard around my neck. That prevented dropping the thermal. While using it as a scanner. And when I remounted the optic on the gun, I slipped the lanyard off my neck.
^^ Apollo with lanyard.
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The Apollo was my first thermal and it was also a clipon. So I used it as a clipon, a scanner and a dedicated scope. I actually used it the least as a clipon once I realized the limitations of most under $10k thermal clipons. But as a 1x scope and 1x scanner it was fine and I used it in those roles a lot.
^^ Apollo as a clipon in front of V/O g2 Rzr 1-6x on .22LR(16), note the lanyard hanging down
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