Red-dot & reflex scopes are handy. Highly-visible reticle, fast acquisition with both eyes open, great for low-light conditions. Recently they have gotten even better, with adjustable reticle patterns, dual-color reticles, and even a variable-size reticle model from Bushnell. But red-dot scopes have a weakness: battery power. Most people who use red-dot scopes have had a battery die on them. Hopefully they had a spare battery handy. If not, good luck hitting the target with no reticle to aim with. Trijicon and other companies have attempted to deal with the battery issue by powering their scopes with tritium capsules and/or fiber-optics . . .
Fiber optics work great during the day, but since there is little ambient light at night, another method of illumination is needed. Tritium is a radioactive gas, and it is not a perfect solution for illuminating a reticle because it only offers limited brightness, and tritium will get dimmer over time (half-life of 12.5 years). As long as the tritium is fresh, a fiber optic/tritium scope like the Trijicon ACOG is very effective. But these scopes are expensive. And once the tritium has decayed to half of its original luminosity, it will be harder to use effectively in low-light conditions, especially in dawn/dusk transitions when the fiber-optics cannot gather enough light.
Trijicon also designed a Tripower scope which adds battery power to the tritium and fiber-optic systems. While that compensates for tritium that dims over time, you are still tied to the battery leash. No battery = no reticle.
Yes, the 12.5 year half-life of tritium is a long time. But that clock starts ticking when the tritium is created, not when the manufacturer built the scope, and not when you buy the scope. For those people who plan on keeping their guns for a long time, that expiration date is a concern. While that may not be a concern for military/police users who have their old equipment replaced regularly, civilian users who pay for their own gear might not like the prospect of having to replace or service their scopes down the road.
Leupold created a new type of scope called a Prismatic scope which uses a unique reticle system which directly addresses the reticle-illumination issue. They have a few different versions, with retail prices of about $500. I mounted a Prismatic scope on a rifle, and did some comparisons with a rifle that has a traditional red-dot scope.
Leupold builds nice stuff, and the Prismatic isn’t cheap. The Prismatic scope is 4-3/8″ long; it has the thickest tube Leupold has ever made, and they claim it is practically indestructible. A rail-mounting bracket is included, along with 3 different risers. The battery-operated illumination module is included as well. It mounts to the Prismatic scope like a scope-ring would, and uses a small N-size battery.
Optically, the Prismatic scope is as sharp as a tack, and about as bright as viewing with the naked eye. There is no magnification whatsoever (unlike some “1x” scopes), and it is easy to keep both eyes open while taking aim. The ocular lens is large, and you don’t lose a lot of forward vision because of non-optical components around the ocular lens. The reticle is a “Circle-Plex”. It is etched into glass and permanently visible. When lighting conditions get iffy, you can activate the illuminator and the reticle lights up in red. But you always have the etched reticle to rely on. Click the picture to get a good look:
Now let’s look at a traditional red-dot; a Bushnell Trophy with 4 selectable red reticles to choose from.
Retail is usually about $90. As long as you have battery power, you have a reticle to aim with. But if your battery dies, you are up the creek without a paddle. The optics are of a smaller diameter than the Prismatic, so you have a narrower field of view. And, the optics are surrounded by a lot of metal, so you lose a little of your forward vision. Click for a bigger view:
The difference isn’t just build quality. The Leupold is a better, more advanced design. I am not aware of any other scope with this reticle system. Aligning the etched reticle and the illumination system takes precision and that is not cheap. And with a permanent daytime reticle, a dead battery will not render your gun useless. That may not be a factor on a range toy, but if you plan on relying on a scoped gun to protect yourself, what price do you put on peace of mind? Murphy’s Law affects us all.
Your mileage may vary, but I am convinced. The Leupold Prismatic is not cheap, but you get what you pay for. Seeing the optical quality, knowing that it’s tough enough to last and having the reassurance of never having to rely on a battery is worth the investment to me. The Prismatic is staying on my SHTF long-gun.