So I love how it works but what would be the ideal image proportions for the 1.sphere and 2. Dome? I load images but as a backdrop they do not appear correct in size, and most times do not look right as a backdrop, but they do the job for lighting up my scene.

Have a read of this thread.

Cool thanks. Another question? Does anybody use Hdr maps on their domes? Does it make a difference in the outcome of the renders lighting?

Yes and yes.

awsome:)

f you need some good quality, free HDR panos to play with, look here.

Cool thanks. A few more questions. Does using Hdr increase render times or use more ram? Also If you convert that hdr image to jpeg I take it that it looses its high range properties?

No significant impact on render times, but being a much bigger file an HDR will take longer to load and require more RAM.

I find that having an HDR on the EnvSphere slows things down when setting up a scene, so I generally work with a low-res JPEG until the last minute, when I swap it for the HDR image.

JPEGs are only 8-bits per colour per pixel, HDRs are 32 bits / colour / pixel so have a huge dynamic range in comparison.

I've been trying to upload an image but that's not working today. Give me a couple of minutes and I'll provide a link.

https://picasaweb.google.com/103511303715998600296/3DStuff?authkey=Gv1sRgCOuVv5a4jPvi8gE#5584298579423246546

Its small but I can see the differences. Now do you export as hdr or jpeg format, because I read somewhere that if you export a Hdr rendered scene to jpeg the Hdr settings become void. Is that true?

What we dealt with above was HDR vs JPEG for incoming images, i.e. ones mapped onto an object (the env sphere in this case).

As far as output is concerned: if you have HDR enabled in render settings you'll have to render to HDR or EXR format to take advantage of the wide dynamic range: none of the others will save the 32-bit image data. Typically you'd open HDR or EXR files in Photoshop or similar (something that can read these formats) and then play with the HDR toning controls when converting to 8- or 16-bit. This provides masses of control over the appearance of the render.

And to anyone else reading, HDR is available in PP2010 only.

Quote - f you need some good quality, free HDR panos to play with, look here.

Cool.... Thanks for this.

Cool thanks. My main concern was if I render with hdr, and convert to jpg in photoshop then it would be pointless if the hdr is lost. I'll mess around with this when I get home.

If you light your scene to have a high dynamic range and render to HDR you can adjust the dynamic range in Photoshop.

For example, here's a scene with a spotlight right in M4's face. The background is a low-res JPEG on an env sphere.

On the left is how it renders into, for example, JPEG or TIFF or PNG. On the left is the same render saved as an HDR file and then adjusted in Photoshop. The specular highlights haven't done too well here, but you can see the kind of control it gives you.

for some reason the free mitsuba.app renderer auto-saves as render.exr.  not sure why, as apparently we can't actually view the luminance data on our typical monitors.

p.s. ISTR bill said that, in order to include the hdr dome background in render, it might need to be as large as 19200X9600.

The image doesnt need to be that big. It doesnt work for close up renders due to distortion but try changing the cameras focal to around 13 to 20. The image on the dome will be crisp and clear even at 1024x512.

Also changing the cameras focal directly relates to the "size" of things in the background.

If you were doing a close up render such as a portrait you wouldnt want the background to be perfectly clear anyway. You would want some blur.

Too few people use the camera settings as they should, if they change them at all. 

The image I used on the envsphere is a jpg at 1024x512.

The first image is with the camera at the default 55mm for focal.

Also notice that since this is a jpg instead of a hdr mapped to the sphere, you really dont get light from any specific direction. With hdr the lighting is much more accurate and you can really tell what direction the light is coming from.

First up is the hdr lighting.

As you can see, the jpg version is a bit washed out without much of a shadow.

And for the curious, the answer is no. Converting a jpg to hdr will not work. The hdr data is already lost once it was converted to jpg.

And this test was done converting an actual hdr image to jpg, so using a jpg that never was a hdr will give you an even more washed out look.

Nice. Does the dome give off the same results as the sphere if using the same image? or will it be different since it is only half.

The only time you would want to use the dome is if your pan image is only 180 degrees in the vertical direction. For instacnce a panorama with just the horizon and sky.

 If you use a full 360 pan with it the 360 degrees of vertical space gets pushed into a 180 degrees.

All I ever use is the envsphere, even when using a ground plane. Even if my image is only 360 degrees x 180 degrees I will resize it and make the bottom half just black.  and the correct dimension ratio for sphereical mapping is 2x1.

Actual image dimensions and ratios dont matter for the envsphere, dome, or hemisphere. what does matter is the ratio of degrees in space.

Envsphere = 360x360 degrees

Dome = 360x180 degrees

Hemisphere = 360x360 degrees but only 360x180 is visible.

cool:)