Category: Dr Shawley’s Blog
The Oligodynamic Effect
The oligodynamic effect is the term given to the roughly 120-year-old discovery that certain metals are toxic to bacteria and other microbes. Certain metals are much more reactive with bacteria than others. Silver, copper, and copper alloys such as brass work well in comparison to stainless steel and aluminum. The metal reacts with the thiol [...]
UV Elimination
Hunters need to blend in with their surroundings to get animals close. This is usually accomplished by selecting camouflage patterns that match the terrain. What if, unbeknownst to you, your camouflage was actually giving away your position? It’s possible!
Chromatic Aberration
Achromatism in scopes occurs because the refractive index of the glass (or the lenses, if you prefer) varies with wavelength. It sounds complicated, but you’ve seen it at work before – especially if you own Pink Floyd’s “The Dark Side of the Moon” album. As white light passes through a lens, it breaks into its [...]
Tricks of the Trade
Scope manufacturers get away with a lot when it comes to consumers. Most of it is sleight of hand marketing. Marketing gurus push positive aspects of a scope’s design without mentioning potential drawbacks. I thought I would take a few moments today to elucidate some of the more common tricks of the riflescope trade.
Warne R.A.M.P.
The Rapid Acquisition Multi-Sight Platform (R.A.M.P.) allows multiple optics to be mounted on your AR. Why be stuck with only one sight? Mount long-range glass on top and a fast acquisition sight on the side. The RAMP allows a small red dot sight to be placed under the ocular of a larger scope making target [...]
Do Scopes Wear Out?
We all know that rifles can wear out. Firing pins fracture, barrels get shot out, and stocks swell and warp with time, but can scopes wear out? In a word, yes. Optics fog, glue cracks, nitrogen gas leaks, and springs wear out. Normally, scope issues are rather apparent. Cracked glass and foggy optics are easy [...]
The Macbeth Test
At first I thought it was just another way to test my retention of Shakespeare’s Macbeth from high school. Fortunately, I didn’t have to remember what Banquo said about the seeds of time in Act I. The Macbeth test in this context pertains to optics. It is a test of color balance and consists of [...]
The Perkinje Effect
Low-light hunting involves more than just your scope, it involves your eyes. Our eyes contain rods and cones. We have one rod photopigment and three cone photopigments – all with different sensitivities. During the day, our three cone photopigments are in charge. This is referred to as photopic vision. During the black of night, our [...]
The Code of Coatings
The box says “coated lenses,” so the scope must be good, right? Maybe. Maybe not. Scope manufacturers needed a clever way of disguising information regarding their anti-reflective coatings. A meeting was called. I imagine it was a dark, smoke-filled room full of lawyers, marketing and advertising executives and a lone engineer. The engineer tells the [...]
Glued vs Mechanical Optics
Lenses in scopes can be secured in several manners, but it ultimately comes down to glued or mechanical. Glue is cheap and easy, and mechanical is robust. However, aside from cost, there are few advantages of glued optics, especially for the consumer. When done with care, glued optics are suitable for most firearms. Notable exceptions [...]
Recent Comments