Benedict Jacka

A further overview of Light sigls.  This section concentrates on one of the most coveted and widely used powers of Light drucraft – invisibility.

Diffraction

Sub-branch:  Manipulation
Type:  Triggered
Appearance:  Blue, transparent
Rank:  C to B+

Bends visible light around the subject, creating a bubble that light cannot enter.  Some diffraction sigls do this by directly bending the light rays, while others temporarily alter the light’s wavelength for long enough for the wielder to hide in the ‘trough’ of the wave.  The second approach is usually considered more elegant, but the first is simpler to do.  Since the light is bent, rather than suppressed (as happens with negation sigls) anyone looking at the wielder sees whatever is behind them.  This allows for ‘true’ invisibility, rather than creating shadows or darkness.

Diffraction sigls are by far the cheapest of the true invisibility sigls, but they come with significant drawbacks.  First and most obviously, diffraction sigls stop ALL visible light from reaching the wielder . . . including the light that would have reached their eyes.  This means that a diffraction sigl, used on its own, blinds the wielder.  Some diffraction sigls attempt to remedy this by allowing a small amount of visible light to reach the area around the wielder’s face, but this still hampers vision, and also means anyone looking at the wielder will see what looks like a disembodied head hovering in mid-air.

A more effective solution is to have the diffraction sigl exclude visible light, but not other frequencies.  (This is normally going to be the case anyway, as the average diffraction sigl doesn’t have the power to screen out the entire electromagnetic spectrum.)  The diffraction sigl can then be paired up with some sort of vision-enhancing effect to let the wielder see in the ultraviolet or infrared range.  This is fairly reliable, but does mean that the wielder has to pay for two sigls instead of one, both in terms of money, and in terms of essentia capacity.  Sigl providers are notorious for selling diffraction sigls at what seem to be reasonable prices, then gouging customers on the vision sigl that goes with it.

Even once the vision problem is solved, diffraction sigls are by no means perfect.  Since the diffraction effect tries to bend light around the wielder, they run into problems when the light’s new course would take it through an opaque object, such as the ground – anyone looking closely at the feet of someone using a diffraction sigl will notice something odd.  For similar reasons, the diffraction field works poorly at close range – the closer a viewer comes, the more they’ll be able to make out a sort of ‘goldfish bowl’ distortion.  Both of these effects are much more noticeable in bright light or if the wielder is moving, and especially if the wielder is moving quickly.  Someone trying to run under a diffraction field in broad daylight may actually be more obvious than if they weren’t using a sigl at all.

Despite these drawbacks, diffraction sigls remain popular.  If you want to be invisible and can’t afford a transparency or active camouflage effect (which most people can’t), a diffraction sigl is usually the only practical option.

Transparency (Matter)

Sub-branch:  Transparency
Type:  Triggered
Appearance:  Pale to very pale pink, transparent
Rank:  B to A

Alters the transparency of the wielder, causing visible light to pass through them.  Often grouped with Light sigls, due to its effect, but this is a Matter sigl and as such is described more fully in the Matter Sigls category.

Active Camouflage

Sub-branch:  Duplication
Type:  Triggered
Appearance:  Almost perfectly clear, with a hint of blue
Rank:  A to S

This powerful sigl intercepts all outgoing light in a similar manner to the Shadowman sigl, but then replaces this light with a copy of the light approaching the wielder from the opposite direction.  So, if the wielder is standing facing north, any light radiating away from their body northwards is instead replaced by a copy of the light coming in from the south.  Thus, anyone looking at the wielder sees what they would have seen if the wielder hadn’t been there.

This sigl is generally considered to be the pinnacle of invisibility drucraft, providing perfect all-round concealment with no disruption to the wielder’s vision.  It is, however, extremely complex and power-intensive, and only the most powerful Light Wells are capable of producing one.

The sigl has no real weaknesses.  It can screen out both visible and invisible parts of the spectrum, and despite its power is only moderately demanding on the wielder’s channelling skill.  Some versions of the sigl struggle to maintain perfect camouflage while the wielder is moving, creating a faint visual distortion in the rough shape of a human body, but higher-quality versions eliminate even this flaw.  However, its price puts it out of range of all but the most wealthy.

An overview of some of the most common Light sigls.  Light sigls are almost always spherical, and their colour varies from light blue to dark blue.

Torch/Torchlight

Sub-branch:  Projection
Type:  Continuous/Triggered
Appearance:  Pale blue, opaque
Rank:  D

The most basic of all Light sigls, and often considered the most basic of all sigls.  Converts essentia into visible light which is projected outwards to illuminate the surrounding area.  Comes in dozens of varieties:  continuous ‘light rings’ which shine when put on, triggered versions designed to be used by channellers, ‘ray’ designs which project a narrow beam, ‘searchlight’ versions which project a cone, and ‘finder’s stones’ designed to only activate in essentia-rich environments, and many others.

Torch sigls have exceptionally low Lorenz ratings, requiring hardly any personal essentia to activate.  Because of this, as well as how cheap and easy they are to produce, these sigls are commonly used as training tools.  Countless generations of drucrafters have learned to sense on a continuous torch sigl, learned to channel on a triggered torch sigl, and (eventually) learned to shape by crafting one for themselves.

Torch sigls can theoretically be made at any rank, but in practice there’s little reason to make one at above the minimum rank of D.  A higher-grade torch sigl costs far more and rarely does anything that a D-rank one couldn’t.

Torch sigls are often casually referred to as ‘light sigls’, but due to how confusing it is to have both ‘light’ and ‘Light’ sigls, formal descriptions generally go with the name ‘torch sigl’ instead.

Dazzle

Sub-branch:  Projection
Type:  Triggered
Appearance:  Blue, opaque
Rank:  D to D+

Essentially a weaponised version of the Torch sigl, the dazzle sigl is made by taking a Torch sigl and adding a capacitor, storing up energy to be released in a single blinding flash.  The light is directed outwards in a cone, both to avoid dazzling the wielder and also to avoid wasted energy.

Dazzle sigls are popular as a self-defence weapon because of how cheap they are:  given how little essentia they require to make and activate, they’re quite cost-effective.  Their main drawback is that they require the target to be looking directly at the sigl, and a weapon that anyone can counter by closing their eyes isn’t what most people would call reliable.

Higher-grade dazzle sigls allow for a more intense flash.  More sophisticated models allow the cone to be narrowed or broadened, allowing the wielder to change the sigl’s focus on the fly.

Gloom/Blackout

Sub-branch:  Negation
Type:  Triggered
Appearance:  Very dark blue, opaque
Rank:  D to C+

The inverse of the Torch effect, this sigl reduces the brightness of light in a sphere around the channeller by converting visible light to free essentia.  The radius of the sphere and the level of light reduction depends on the power of the sigl.  D-rank and D+ versions produce an area of shadowed gloom, while versions of C-rank and above produce a sphere of total darkness.  The weaker versions are usually referred to as ‘gloom’ sigls, while the more powerful ones get the ‘blackout’ label.

Obviously this sigl blinds the wielder just as thoroughly as it blinds anyone else.  As such, to be effective, it is typically combined with some way for the wielder to see while everyone else can’t.  The most common approach is to design the sigl in such a way so as to negate most frequencies but exclude certain ones – the wielder can then use light-enhancing goggles or another sigl to see in those specific frequencies, while everyone else is blinded.  Used in this combination, this sigl becomes a fairly cheap and effective method of ‘invisibility’.  The main drawback, of course, is how obvious it is – a giant sphere of darkness is hardly subtle.  As such, it is much more useful at night or in other poorly-lit environments – in daytime, the amount of attention it draws tends to counteract any benefit it might provide.

Shadowman

Sub-branch:  Negation
Type:  Triggered/Continuous
Appearance:  Very dark blue, translucent
Rank:  C to C+

A more advanced variation of the Blackout sigl that affects a very small area around the wielder, but works only on outgoing radiation.  Visible light travelling away from the wielder is converted into free essentia;  visible light travelling towards the wielder is unaffected.  The result, to observers, is to make the wielder look like a sort of humanoid shadow, fuzzier around the edges and pure black at the core.  The wielder, meanwhile, can see just fine, although the loss of indirect light does hamper them slightly – wielders often describe it as like trying to see on a very cloudy day.

While usually thought of as a stealth sigl, in some ways this sigl does the exact opposite.  A drucrafter with an active shadowman sigl is, in most cases, incredibly easy to spot – in any conditions other than total darkness, the huge moving blot of shadow is very obvious.  However, while the shadow is obvious, actually seeing the wielder or making out their movements is close to impossible.  You can tell that someone’s there, but not who they are or what they’re doing – useful for those who don’t want to be identified.

It should not be a surprise that this sigl is heavily associated with criminal activity, particularly raiding and other forms of theft.  It’s illegal to sell to the public in most countries, and possessing one is typically seen as highly suspicious.