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starbase1
10-18-2008, 07:02 AM
I'm getting faster at this stuff, only started yesterday evening...

Four shots of a Solar Sail spacecraft near Jupiter. (1 is very dark, as its of the unlit side)

I also made an FLV flash animation, 1.5 Mb, which I am rather pleased with:
http://www.starbase1.co.uk/solar-sail.flv

Nick

JBT27
10-20-2008, 01:55 PM
The animation is nice, though the raw FLV doesn't do anything by itself, I had to load it into Flash Pro and save a project out to see it.

Never clear on whether solar-sails should be dark or light. I recall many of the experimental materials from the 1980s/90s were very reflective.....I don't know much about them though, to be honest.

Very elegant concept and much under-used in space-art. I wonder if your sail should be more specular, given that Jupiter is a fairly big gibbous phase, the Sun will be behind the camera and in a position to believably do this. I don't mean consistently shiny, I just mean a sudden glaring reflection. The animation is elegant and stately as such ships should be, but I feel it lacks a bit of sparkle (pun intended).

Julian.

RonGC
10-20-2008, 02:44 PM
Solar sails need to be reflective, like a mirror so that the speeding photons hit and bounce off leaving their momentum on the sail giving it a push. A dark material will absorb the photons and not get a momentum transfer. However that said a really mirrored sail would reflect the environent, and as space is black the sail could appear to be black.

Ron

starbase1
10-20-2008, 03:02 PM
Yep, it is actually reflective, but there's nothing to reflect!

Although I thought it was finished, I did some tweaks - including adding Europa behind the ship, to be reflected. I'll try and get the new 'finished' one up real soon!

Nick

starbase1
10-20-2008, 03:22 PM
OK, some new stills of it going past.

And a Divx video clip, 11 Mb.
http://www.starbase1.co.uk/solar-sail.avi

Nick

JBT27
10-20-2008, 03:51 PM
Yeah, looks good - adding Europa has given the animation alot of depth, though that sail still needs that sparkly glaring shiny something-or-other. Looking great though :thumbsup:

Julian.

starbase1
10-20-2008, 04:09 PM
Yeah, looks good - adding Europa has given the animation alot of depth, though that sail still needs that sparkly glaring shiny something-or-other. Looking great though :thumbsup:

Julian.

Thanks!

I can't think of an excuse to get anything else big and bright into the scene! :D
Io would be too small to light stuff up.

Chrome in space is always a pig to pull off...

Nick

RonGC
10-20-2008, 07:10 PM
Well technically speaking as it is photons from SOL pushing the sail it should be facing SOL so a very tiny distant sun would probably be reflecting off the sail at some point towards the end of the animation, however adding the moon reflection has upped the quality of the simulation.

I also like the subtle light play over the front surface of the sail as it is moving toward then past the camera.

Ron

Giacomo99
10-20-2008, 07:47 PM
I can't think of an excuse to get anything else big and bright into the scene!
Nick

You could crank up the brightness and overall density of the background stars. As it is they seem a bit dim--even on a clear night here on Earth (away from urban areas) it's possible to distinguish a shadowed object against a starry sky. So out in deep space it should be even easier. I put together a sloppy comp to show what I mean:

http://home.earthlink.net/~bucket/Sail20Oct.jpg

JBT27
10-21-2008, 03:18 AM
Thanks!

I can't think of an excuse to get anything else big and bright into the scene! :D
Io would be too small to light stuff up.

Chrome in space is always a pig to pull off...

Nick

Fair point! The reality is that you have more closely mimicked how it would really be than most of the slick space stuff we see on TV - out there, you would not see an awful lot during space travel - only near to stars and bright planets.

Though William Hartmann wrote a good article years ago on depicting brightness levels in space (don't have it now but it may be somewhere on the web). He cited Pluto landscapes as a prime example, with the Sun so far and dim, but pointing out that after a few hours your eyes (and brain) would perceive it as much brighter than it really is, through dark-adaptation of course. Likewise a long exposure by a camera - it's all down to what you intend the imaging to be done by, eyes or mechanical/electronic.

There was a thread elsewhere about having stars appear in shot, versus why the Apollo shots never showed stars in the photos - same thing of course.

I think often you have to infer the darkness of space in imagery rather than actually depict it that way, hence my notion of the Sun glaring momentarily in the solar-sail - I still think that would look great. :)

Julian.

starbase1
10-21-2008, 04:40 AM
Yep, when I do outer planets, (Uranus and further) thats when I really crank up the brightness of the background stars, to try and imply the viewer is well dark adapted.

As an artist member of the IAAA, I always try and make things realistic if I can!

JBT27
10-21-2008, 04:50 AM
Ah.....quite right too!!!

I used to be a member of the IAAA, actually back around when it started I think, but left when it seemed very US-centric and I didn't get an awful lot out of it except the occasional newsletter.

However, I have been thinking of joining again, probably as the company this time - only two of us :)

Julian.

starbase1
10-21-2008, 09:26 AM
Ah.....quite right too!!!

I used to be a member of the IAAA, actually back around when it started I think, but left when it seemed very US-centric and I didn't get an awful lot out of it except the occasional newsletter.

However, I have been thinking of joining again, probably as the company this time - only two of us :)

Julian.

My experiences have been somewhat mixed too. On the minus side I have been blasted for 'top posting', and also for giving my stuff away occasionally. I've also started arguments about why their web site is so poor, unpopular in terms of visits, and delivers so little traffic to members via the links there.

The old guard who prefer splodge and stick to digital will often jump at me, but I get a lot of off list support. And I have made some good friends there, but we generally take discussions off the main list rapidly.

And it's by no means universal that the old guard are the problem - it has been a real pleasure getting to know David Hardy better, he is always contructive and a pleasure to deal with.

And whatever the medium, or methods there's no doubting the awesome level of talent within the organisation. It does seem to deliver a lot more to the professionals though...

Nick

Nick

JBT27
10-21-2008, 02:10 PM
Hmmm.....it doesn't sound like an awful lot has changed. David Hardy is always good - his 'Challenge of the Stars' got me started with all this when my parents gave it me for Christmas in 1972 I think. Corresponded and spoke on the phone with him when I got started in the early 1980s, and had some correspondence with some of the artists I presume are now 'the old guard' in the US.

I spent alot of years illustrating astronomy books, but eased away from it for awhile while pursuing my archaeological work. Now that's more established I'm coming back to working on space art as well again, so reckon I might as well re-join.

I'm out of touch with what many of the older artists are working with now - the digital stuff I was seeing wasn't that good, but that was in the early days, and Bryce, I recall, figured as a recommended package for space artists.....how things have changed - it shouldn't be an issue, but that's easier said than done I reckon.

Julian.

starbase1
10-21-2008, 04:18 PM
Bryce, I recall, figured as a recommended package for space artists.....
Julian.

Good grief, things were THAT bad!!??

JBT27
10-22-2008, 03:23 AM
Good grief, things were THAT bad!!??

.....oh yes!!!..... :eek: