Steel Chrome Ball for HDRI

[Ironhalo]

out of curiosity, is shooting and stitching a panoramic not an option? i've created hdr images using both methods, and a panoramic using a fisheye is so much easier.

anyway, we bought our chrome sphere off this site:

http://www.gazingballoutlet.com/?gclid=COvshsj0ipkCFR0Sagod7A8pnw

[leif3d]

Thanks for the site Paul.

I don't have access to a Fisheye lens, so I needed a cheaper solution. :blush:
Plus...I've read that capturing the reflectance of an environment is more accurate for use in a 3D app.

[chronic]

I bought a couple of stainless steel gazing balls from amazon - they are very sturdy (steel tends to be) but they are by no means optically perfect. They have slight imperfections in the surface and it shows in your hdri unwraps. but for lighting a 3d scene and reflections they are fine. you can get sizes from 4" to 12" - the larger ones will show imperfections less, but probably weigh a lot more and are harder to handle.

i bought 2 4" ones (one for reflections, one for grey sphere), and glued a long steel bolt to the bottom of each with a little bit of plumbers putty, its very sturdy.

Amazon link (http://www.amazon.com/Gazing-Globe-Stainless-Steel-Silver/dp/B00194BJEW/ref=pd_bbs_sr_3?ie=UTF8&s=home-garden&qid=1236281388&sr=8-3) - just make sure you dont get a colored one, that would suck

[leif3d]

Thanks for the input leonardo (I just sounded like a teenage mutant ninja turtle).

So you used another one for diffuse lighting? I assume you painted it...
Why not use a styrofoam ball? any advantages?

[chronic]

i bought two in case i screwed one up with the plumbers putty, which i did, so that one got painted.

also i don't like Styrofoam

a grey ball is not very useful imo, unless you are going for some really optimized shaders in renderman. i have never had the occasion to use it.

[leif3d]

Thanks again.

[berniebernie]

a grey ball is not very useful imo, unless you are going for some really optimized shaders in renderman. i have never had the occasion to use it.


isn't it meant to help during compositing to match plate light ?

[jasonhuang1115]

Hi, Leonardo,

Would you mind sharing how you make the gray sphere from the gazing ball? Did you paint it yourself?
I have been searching a pre-made gray ball everywhere, but couldn't.

Thanks.


i bought 2 4" ones (one for reflections, one for grey sphere), and glued a long steel bolt to the bottom of each with a little bit of plumbers putty, its very sturdy.

Amazon link (http://www.amazon.com/Gazing-Globe-Stainless-Steel-Silver/dp/B00194BJEW/ref=pd_bbs_sr_3?ie=UTF8&s=home-garden&qid=1236281388&sr=8-3) - just make sure you dont get a colored one, that would suck

[Als]

Search in garden shops. They should have nice spheres, without the weight...
They are rare find for some strange reason.
Also some furniture shops used to have them.
If all else failse, try looking them up in shop decorations shop.
They have all sort of things, mirror balls should be one of them...

Als

[Ironhalo]

target may have them, but im sure their stock won't be the same from store to store. you could always spend a tone of cash and get a ball bearing :argh:

[leif3d]

Thanks for all the ideas.

I've looked in my local Wallmart, Target, Kmart, Home Depot, etc...but no one had them when I needed one a while back. I ended up lighting the scene manually to photographs of the set. They did tell me they where more popular during summer, so to come back then ...:argh:

[chronic]

pic:
you can see how i attached the bolt with plumbers putty - Grey was spray painted. They are steel but hollow, made from two hemispheres, so not heavy, but solid. The bolt-to-sphere joint feels solid and sturdy, plumbers putty is my friend.

4" spheres, you can clearly see some of the imperfections and anisotropic highlights from whatever sanding and buffing was done to the plain one. again, this isn't really a problem if you are using it only for lighting and reflections, but wouldn't be suitable for a visible background. in retrospect 8" spheres would have been a better choice.

http://media.leocov.com/cgtalk/lightprobe_t.jpg (http://media.leocov.com/cgtalk/lightprobe.jpg)
click for larger.

[leif3d]

Thanks for the great explanations man.

I think I have a clear picture of what I need now.

:thumbsup:

[jasonhuang1115]

Thanks a lot, Leonardo. The explanation and picture are great help.