John Mitchell explains the facts behind UV finishing and how combining it with other components such as lure action and colour contrast can enhance the attractiveness of a lure to predatory fish.
Ultraviolet, or UV, lure finishes are a relatively new addition to fishing tackle. The premise of their existence is found within the fact that the vision of many predatory fish includes the capacity to see this short wavelength light. With a range of science in hand, many lure manufacturers have incorporated varied manufacturing processes in order to position UV lure finishes as necessary to the success of lures.
The Rapala Product Development Team launched a two-year fact-finding mission to research and test ultraviolet lure finishes. The resulting release of UV Bright finishes within Rapala, Storm, Luhr-Jensen and Blue Fox product lines incorporate research conclusions to deliver anglers the best components of UV technology.
Beginning with the most successful lure actions available, UV technology can enhance the visibility of lure finishes under the greatest range of water conditions.
VISION: HUMANS VERSUS FISH
Naturally, anglers tend to judge lure finishes as they appear to the human eye. This approach overlooks the basic biological differences between the human eye and the eye of fish. Where the human eye has a great capacity to distinguish detail, the eye of a fish does not. The rods and cones within the eye of most fish are arranged in a manner that highlights sensitivity to motion and contrast at the expense of detail.
Visible light is another issue. Where colours are of extreme importance in our environment, beneath the water’s surface, colours in the visible spectrum are quickly filtered out as depth increases. Colour removed, what remains are shades of grey which could be the underlying reason for fish’s high sensitivity to motion and contrast.
Ultraviolet means “beyond violet” and considering ROYGBIV (Red, Orange, Yellow, Green, Blue, Indigo, Violet), the acronym for the colour spectrum, it’s light that exists beyond the shortest wavelength of visible light, violet. For fishery applications, UV discussion is confined to UVA light, with wavelengths ranging from 400 to 315 nanometers. Light within this spectrum penetrates the water column much deeper than visible light, and is available in periods of low visible light, like dawn, dusk and overcast conditions. In short, the principles of UV lure finishes centre on this depth of penetration and greater availability than visible light, and the corresponding theory that a lure that is more visible, is more available to hunting predators.
Sight, however, is only one component of predatory fishes’ sensory system. Additionally, fish rely heavily on vibration or “feel” to hunt. A fish’s lateral line is a highly sensitive string of nerve receptors positioned along each side of their body. In their water environment, many predatory fish can actually feel the vibration of prey species, and lures, well before a visual connection is established.
Realizing the importance of the combined senses fish use to locate and attack prey, Rapala designers developed the following priorities to guide the critical components of lure attraction.
- Lure action is paramount. Vibration available to the lateral line coupled with a well-developed sense of motion is the key to predatory species ability to locate, identify and attack prey. This may explain why certain lures are continually top performers over multiple decades relying on basic finishes covering very well designed actions.
- Contrast is more important than detail. It’s very likely that predatory species do not assess lures for exact realism. In fact, too much detail may hinder lure attraction by diminishing its ability to deliver contrast. This is quite possibly the reason chartreuse is such a successful colour in so many fisheries. Chartreuse stands out vividly in all water environments.
- Properly executed UV finishes should increase the visibility of lures to fish at depth and in periods of low visible light. The science shows the capacity of many fish species to see within the UVA spectrum. Where the visible light spectrum begins to be filtered out at depths of five feet or less (red is the first color to go), shorter wavelength UVA light can penetrate to depths of hundreds of feet.
Putting the science to work, Rapala designers incorporated the following components in the delivery of a UV platform that provides anglers the best combinations of lure actions and finishes available.
PRIORITIES IN PRACTICE
- Begin with the finest lure actions. In the absence of UV technology, the lure actions of Rapala, Storm, Blue Fox and Luhr-Jensen by themselves trigger an aggressive response from game fish. With thousands of examples of lures where the finish has been chewed off nearly in total, the vibration and action alone continue to solicit strikes.
- Incorporate a reflective base. This consists of chrome on Luhr-Jensen and Blue Fox lures, and white on Storm lures. We see colours by what they reflect. Where chrome reflects individual colours that are bounced off of it, white reflects all colours simultaneously. Both reflective bases utilize reflection to capture the attention of fish’s motion-sensitive eyes.
- Utilize fluorescent paints only. Fluorescence is the emission of light that has been absorbed. In many instances the absorbed light is within the UV spectrum and its’ release is at a longer wavelength within the visible spectrum. For lures, absorbed UV light is released from the lure finish to highlight visibility to predators.
- Deliver high contrast. Contrast plays to the strength of fish vision. Regardless of ability to discern specific colours, simplified patterns with strong contrast are very available to the eyes of game fish. Consider specific colours with regard to light or dark and utilize that value to assure lures stand out.
- Overspray with optical brighteners. The components are the same that are in laundry detergents to boost the vividness of colours and whites. Their function is to absorb light in the ultraviolet region and immediately re-emit it as blue light. Blue light enhances perception of colours and is common in fish tank lighting to make fish stand out dramatically against their environment.
- Provide definitive colour selection. Back to ROYGBIV as the basic components of the visible spectrum, each lure family from Rapala, Storm, Luhr-Jensen and Blue Fox delivers finishes that cover the range. Many water bodies, based upon the geography of their environment, depth, water clarity and chemical composition filter light and colours at different rates. It’s why top lure finishes often change from one body of water to the next. The refined selection of UV Bright finishes anticipates the need with finishes drawn from the full range of the spectrum.
Rapala’s Tail Dancer Deep in UV Bright Orange Tiger finish.