[Josephus Holt]

I'm just looking into using hdr images instead of phys sky.
Is there a way to preview the hdr background image (rendered shadows does not show it) so that I can correctly offset the uv 's without having to run multiple test renders?
If I enable Screen Mapped, it looks like it automatically scales to the image size, is that right?
When enabling Screen mapped, I suppose that the output image size and hdr image size need to be the same (or at least same proportions), otherwise the hdr image will be distorted, is that right?
I'm assuming that although the "Use Sun" option can be checked, that it does not do anything (I did not see a difference when I checked it)?
I'm finding that the background image washes out when I set the intensity high enough to get a daylight atmosphere inside a room. To correct that, do I use a separate (higher intensity) hdr image for illumination, or are there other options?
Thx much! Joe

[JDHill]

Is there a way to preview the hdr background image (rendered shadows does not show it) so that I can correctly offset the uv 's without having to run multiple test renders?

Are you familiar with the plugin's Environments toolbar?

If I enable Screen Mapped, it looks like it automatically scales to the image size, is that right?

Correct.

When enabling Screen mapped, I suppose that the output image size and hdr image size need to be the same (or at least same proportions), otherwise the hdr image will be distorted, is that right?

You can stretch the image independent of the output size using the Scale/Offset values in the IBE channel.

I'm assuming that although the "Use Sun" option can be checked, that it does not do anything (I did not see a difference when I checked it)?

Afaik, the sun gets disabled if you are rendering with the Illumination IBE channel enabled. To disable that, un-check the 'Use Background for all Channels' box so that you can set up each channel independently.

I'm finding that the background image washes out when I set the intensity high enough to get a daylight atmosphere inside a room. To correct that, do I use a separate (higher intensity) hdr image for illumination, or are there other options?

Again here, make sure to try un-checking 'Use Background for all Channels' so that you can set the intensity separately for your illum channel. Also, and I'm not an expert in this, but I believe that using a high-quality HDR will help quite a bit. You could surely get better info about that from someone else.

[Josephus Holt]

Are you familiar with the plugin's Environments toolbar?

Nope, but getting familiar now, that's what I was looking for, thx much. Was expecting all to be shown with the Rendered Shadows setting.

Again here, make sure to try un-checking 'Use Background for all Channels' so that you can set the intensity separately for your illum channel. Also, and I'm not an expert in this, but I believe that using a high-quality HDR will help quite a bit. You could surely get better info about that from someone else.

Yes, I saw that, you confirmed what I was thinking.
Along that line, when 'Use Background for all Channels' is enabled, and if I want/need to use the reflective channel, I have to manually try to match the background screen map (if I have that enabled), either that or not use the screen mapping in the background image and then just use the same manual settings. Coming at this as a noob, would it not make life easier to be able to check "screen mapping" for the other channels as well?
I'll post elsewhere as to what constitutes a high quality hdr.

Thx much for your help, Joe