GURPS Powers: Enhanced Senses

[Flyndaran]

What makes me think that having a fourth color receptor would lead to tetrachromatism aka having four color receptors?
Huh?

[dcarson]

UV should let you spot polar bears. When they look for them from the air they use UV cameras. In visible light they are well camouflaged, in IR they are well insulated, in UV they are black because they hairs are UV light pipes the get the extra warmth.

[Anthony]

Originally Posted by Flyndaran

What makes me think that having a fourth color receptor would lead to tetrachromatism aka having four color receptors?
Huh?

What makes you think a fourth color receptor is needed to see UV?

[whswhs]

In any case, I was able to rewrite Infravision because there are multiple bands of IR that can get through the atmosphere to different degrees, and that have different optical properties; the conventional GURPS treatment somewhat conflates the properties of very near IR with those of IR emitted by things like mammal bodies. UV has only one narrow band just above violet; higher frequencies don't get through the atmosphere—that's why they're called "vacuum ultraviolet." So I couldn't very well say "this is the version of the advantage that's limited to this narrower set of frequencies," because that narrower set of frequencies is what Ultravision is.

[Refplace]

My thoughts on the book.
I liked the mods fir range being brought into line with other ranges, including touch and contact.
I liked the addition to normal senses and many of the writeup for example senses.
I especially liked the many animal examples and will be redoing some templates based on this book.
I liked the example skill bonuses from senses and the sight and hearing charts.
I liked the power groups.

What is missing that I had hoped would be here were some alternate rules for some overpriced advantages or ones that I think should scale better.
Also detects and supernatural senses, though they still get a boost with a lot of the material here.

What I liked most was the classification and sense hierarchy explanations.
Should cut down on some questions.

[whswhs]

Originally Posted by Refplace

What I liked most was the classification and sense hierarchy explanations.
Should cut down on some questions.

Well, I hope so. I had a lot of those questions myself when I started working on the book; I needed to work the categories out to answer my own questions . . . and then fill in a gap or two where the existing rules didn't quite seem to describe a plausible sensory abiiity.

[Tiggurix]

Inb4 someone declares they're making a mantis shrimp campaign now. :P

[Flyndaran]

Originally Posted by Anthony

What makes you think a fourth color receptor is needed to see UV?

Our short wave receptor only barely detects intense UV when the opaque lens isn't in the way. And most animals that can see it have a specially dedicated pigment for it.

[Flyndaran]

Originally Posted by Tiggurix

Inb4 someone declares they're making a mantis shrimp campaign now. :P

Their vision is horribly over-designed with over a dozen color receptors and rotating polarizing lenses. Likely it is so complex to keep the amount of processing required by the brain to a minimum.

[Anthony]

Originally Posted by Flyndaran

Our short wave receptor only barely detects intense UV when the opaque lens isn't in the way. And most animals that can see it have a specially dedicated pigment for it.

Most bees, ants, and the like have three receptors, like humans; most birds have four, a few birds and many butterflies have five. The tetrachromat version is a legit perk, but it's mostly for being a tetrachromat, not for being UV sensitive.

In any case, having read through it, most problems are the fault of Basic, and thus out of scope for a supplement to do anything about. The exceptions are:
Normal Senses and Modifiers
Seems to be treating vision as 20p, hearing as 10p, smell as 2p, touch as 10p. Given that Blind is [-50], Deaf is [-20], No Sense of Smell is [-5], and Numb is [-20], those numbers are odd.
The Mark 1 Eyeball
The 20:20 letters on a Snellen eye chart are 0.35", not 0.07"; using a SM of -18 is equivalent to saying a human has SM -6 because his legs are only 6" wide.