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Rifles, Reloading, Optics, Equipment
Long Range Scopes and Other Optics
Best low light scope!!
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<blockquote data-quote="LouBoyd" data-source="post: 984020" data-attributes="member: 9253"><p>The fundamental rules of optics prevent any passive (non electronic) scope from presenting an image which has an apparent surface brightness greater than what you can see with the dark adapted naked eye. However, the dark adapted naked eye uses only the non color sensitive rods of the eye, which are only about 1/100 as dense (frequent) in the eye's fovea as the color sensitive rods, and because of that give only about 1/10 the linear resolution of the normally illuminated eye. So to see with normal resolution you need about 10X magnification just to make up for the sparse distribution of the dark adaptable rods. So to have "naked eye" resolution one needs at least 10x magnification with an objective lens with 100 times the area for it's entrance pupil compared to the dark adapted eye's entrance pupil to give an equivalent apparent surface brightness. That mean a 50 to 60 mm objective. The scope at best can only preserve your "night vision" allowing your eye to stay dark adapted, so unless they're extremely faint illuminated reticles don't work well. Non illuminated reticles need to be 10x wider than in daytime scopes to be equally visible which doesn't do good things for accuracy. There is no "make or /model" scope which is particularly better than others. Good optical coatings help but there's no magic. Covering you head with a black cloth and looking only though the scope will help preserve dark adaptation. </p><p></p><p>No optical scope can change the F-ratio of the light coming into the human eye which is about F-3. Electronic night vision scope use several features to enhance vision. </p><p>1. Faster F ratio optics. using lenses faster than F-1 gives about a x10 increase in apparent image brightness.</p><p>2.higher quantum efficiency detection gives about an X4 improvement in brightness.</p><p>3. using electronic gain to increase the brightness so the eye's cones in the fovea accounts for a 10x improvement in resolution over the dark adapted eye. </p><p>4. A Gen 3 or 4 Galium Arsinide phtocathode on the image tubes use the natural sky glow in the 700-900 nm wavelenght range which is about ten times brigther than the natural sky glow in the visible 400-600 nm range.</p><p>Those together. allow a gen 3 scope on clear moonless nights to give roughly equivalent performance to a 4x optical scope although without the advantage of color vision. </p><p></p><p>Know your state hunting laws. Some don't allow hunting at all during certain nighttime hours. Some don't allow artificial illumination. Some don't allow electronic intensifiers. </p><p></p><p>If your state laws allow it my suggestion is to use about any 6 x 40 rifle scope in conjunction with a 35 watt halogen spotlight for the clearest, and longest range night vision rig which gives natural full color images. It will be good to about 400 yards. Mounting the light away from your rifle can improve range by reducing near-field back scatter. </p><p>For longer range illumination you can use parachute flares.. The available HK 26mm flare guns give 45 seconds of stable white light when fired downrange. Plenty of time to spot animals and take shots.. </p><p>Again, state laws vary.</p></blockquote><p></p>
[QUOTE="LouBoyd, post: 984020, member: 9253"] The fundamental rules of optics prevent any passive (non electronic) scope from presenting an image which has an apparent surface brightness greater than what you can see with the dark adapted naked eye. However, the dark adapted naked eye uses only the non color sensitive rods of the eye, which are only about 1/100 as dense (frequent) in the eye's fovea as the color sensitive rods, and because of that give only about 1/10 the linear resolution of the normally illuminated eye. So to see with normal resolution you need about 10X magnification just to make up for the sparse distribution of the dark adaptable rods. So to have "naked eye" resolution one needs at least 10x magnification with an objective lens with 100 times the area for it's entrance pupil compared to the dark adapted eye's entrance pupil to give an equivalent apparent surface brightness. That mean a 50 to 60 mm objective. The scope at best can only preserve your "night vision" allowing your eye to stay dark adapted, so unless they're extremely faint illuminated reticles don't work well. Non illuminated reticles need to be 10x wider than in daytime scopes to be equally visible which doesn't do good things for accuracy. There is no "make or /model" scope which is particularly better than others. Good optical coatings help but there's no magic. Covering you head with a black cloth and looking only though the scope will help preserve dark adaptation. No optical scope can change the F-ratio of the light coming into the human eye which is about F-3. Electronic night vision scope use several features to enhance vision. 1. Faster F ratio optics. using lenses faster than F-1 gives about a x10 increase in apparent image brightness. 2.higher quantum efficiency detection gives about an X4 improvement in brightness. 3. using electronic gain to increase the brightness so the eye's cones in the fovea accounts for a 10x improvement in resolution over the dark adapted eye. 4. A Gen 3 or 4 Galium Arsinide phtocathode on the image tubes use the natural sky glow in the 700-900 nm wavelenght range which is about ten times brigther than the natural sky glow in the visible 400-600 nm range. Those together. allow a gen 3 scope on clear moonless nights to give roughly equivalent performance to a 4x optical scope although without the advantage of color vision. Know your state hunting laws. Some don't allow hunting at all during certain nighttime hours. Some don't allow artificial illumination. Some don't allow electronic intensifiers. If your state laws allow it my suggestion is to use about any 6 x 40 rifle scope in conjunction with a 35 watt halogen spotlight for the clearest, and longest range night vision rig which gives natural full color images. It will be good to about 400 yards. Mounting the light away from your rifle can improve range by reducing near-field back scatter. For longer range illumination you can use parachute flares.. The available HK 26mm flare guns give 45 seconds of stable white light when fired downrange. Plenty of time to spot animals and take shots.. Again, state laws vary. [/QUOTE]
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Best low light scope!!
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