Re: For the artists: RIP

["Mickey Rowe;893-2446" <mrowe@lifesci.ucsb.edu>]

Colin McHenry <cmchenry@westserv.net.au> wrote:

> 1. you need a huge team of artists to get everything right; [ ...]
> and the background and lighting need to be worked out

> It is inevitable that most of the people in that sequence will
> understand very little of the basics about what they are dealing
> with (for the sea monsters, apart from the basic anatomy, this means
> things such as; how animals move in water, how light behaves in
> water,

> in the news article they mentioned that they wanted to start with a
> marine environment because most people looking at it wouldn't know
> enough to spot mistakes, but I think this approach may have
> backfired on them.

Given my experience... I'd have to say, that yes, there are other
indications that the approach backfired on them.  I was contacted by
one of the editors at the end of July for comments on earlier drafts
of what became the huge eye of the _Temnodontosaurus_ in the insert
that went along with the magazine.  I put a bit of time and effort
into suggesting things about how they might improve it, and...  Well,
I'm not sad that my name didn't make it into the list of consultants
because so far as I can tell, they didn't take any of my advice.

There were several things that I commented on, but the number one
thing I told them -- which is almost inarguable -- was that you should
not expect to see much (if any) reflection of light off of the cornea
of an animal under water.  Some reflection off of the lens, possibly,
but not the cornea (the transparent part of the front of the eye).

You get reflections where there is a change in refractive index
between two media.  There is a large difference between the refractive
index of air and that of a typical cornea, so you expect to see things
like a bright patch (effectively an image of the sun) reflected off of
an eye in air.

But all aquatic vertebrates -- independent of their evolutionary
histories -- have corneas with refractive indices similar to that of
the eyes of terrestrial vertebrates.  That is to say, the refractive
index of a vertebrate cornea is similar to the refractive index of
water.  The refracting power in aquatic eyes is in the lens, not the
cornea.  So the specular glint of the sun and the image of the
belemnite shouldn't have been there on the cornea of the
_Temnodontosaurus_.  I offered that advice on August 3rd.  I got a
response, but never any requests for clarification or anything like
that.

Can anybody tell me if the turnaround was that slow?  They did make
changes -- originally the glint of the sun was at the bottom of the
eye.  Simple ray-tracing should have told them that that wasn't
possible since the view was from the side of the eye.  You'd have only
gotten glint off of the bottom if the sun were beneath the animal
(accepting you'd get a reflection off of the cornea...).  I did point
that out, but since they didn't take any of my other advice, I suspect
that that mistake was caught by the artists independently of me.

As a related aside... I don't have the issue with me, so I can't tell
you where this was in the print version, but if you go to the website
(you may not want to do this from a dial-up modem):

http://www7.nationalgeographic.com/ngm/0512/feature3/multimedia.html

check out the fourth image during the "Introduction"...  The lighting
there does not seem possible unless it was created by a flash on the
camera held by a person photographing the scene.  Perhaps that was the
intention.  You'd think they'd have seen fit to mention that if it was
their intention...

Ken, none of these comments have anything to do with the medium.  I
may not be as old as you, but I'll challenge you to an open-mindedness
duel any day of the week :-)

-- 
Mickey P. Rowe     (mrowe@lifesci.ucsb.edu)