OK, let's start. Add a sphere to your scene and name it "Backdrop-sphere". We will use a large sphere instead of a Sky object, because that way we will have better control over things. The scene for this tutorial is just a plane and a sphere so I made my Backdrop-sphere with a radius of 900m. If you'd rather use a Sky it will not pose any problems.

Then create a new material and name it ”Backdrop”. Normally we would simply load the HDRI in the Luminance channel, increase the Brightness, map it to Backdrop sphereand we would be (almost) done. In this tutorial we will map it to the sphere all right, but we will use the HDR-image just as a normal material. The Backdrop-sphere is there to show the HDR-image only, not to calculate the Global Illumination effects. So open up the material and load the HDRI you’re gonna use, and in this tutorial it will be the kitchen-probe. Now, the kitchen-probe is quite dark as it is so we'll follow the usual procedure and increase its Brightness. Remember that this material is for show and reflection only, not Global Illumination. It's there for making a background and basically giving something for your shiny objects to reflect – it's not creating the actual lighting. Load the kitchen-probe into the Luminance and crank up the brightness toaround 500. When you’re done map the HDR-image normally to the Backdrop-sphere (holding down Shift while dragging the material to the sphere will assign it using spherical mapping without any dialogs showing).

After you’ve mapped the sphere, add a Render tag to it and untick "Seen by GI". Why? The Sky is there to provide a background and a basis for reflection, but we don’t wan’t it to affect the Global Illumination.

Next make a sphere, name it ”HDRI-sphere” and set it's radius big enough to cover the whole scene, including your Backdrop-sphere. I gave mine a radius of 1000m. This sphere is what’s going to create the Global Illumination HDRI effect on our scene, only with a little bit more control than you have in Matt’s tutorial, so size does matter – smaller sphere will give different result than a larger one. just remember to keep it bigger than the Backdrop-sphere. Put a render tag on the sphere, and untick everything apart from "Seen by GI". Why? This ensures that the sphere doesn't render, but it's effects do.

Now for the material to go on the HDRI-sphere. Create a new material, name it ”HDRI” and uncheck everything but the Luminance-channel. In the Luminance channel, set the brightness way up high – I suggest around 1000 to start off with. Then add bhodiNUT Fusion and set the Mix to "Multiply". When you’ve done that it’s time to set the bhodiNUT Fusion-channel to work for us.

bhodiNUT Fusion is used to fuse two materials together, be it a bitmap and a bhodiNUT material or two bhodiNUT materials. Click ”Edit” and enter bhodiNUT Fusion. In the top channel put in something in a shade of grey or white or black, it's not important which shade, just that it's a completely unsaturated colour, so you could use a gradient with black at both ends or whatever. For this tutorial we’ll go with a nice gray shade achieved by using bhodiNUT Hue.

In the bottom channel put in a bhodiNUT Brightness Contrast. Set the blending mode of the fusion to be "Saturation" and the mix to be around 80%. This will now control how saturated the HDRI effect will be (or how juicy the colours will appear to put it another way).

Now edit the Brightness Contrast. Put your HDRI image (the kitchen-probe) into the Brightness contrast and change the settings to really highlight the lights. Here we simply lowered the brightness by about 3% and raised the contrast by about 20%. Keep an eye on the preview: you're aiming to get an image that's mostly pretty dark (or even black) with a couple of bright areas where the main light sources are. This is because otherwise HDRI lighting can leave you without true shadows in C4D and by upping the contrast we're able to control how bright the lights are, and how tight they fit to the light shape, thus controlling the overall lighting so that you get much tighter and sharper defined shadows in your scene.

When you’re satisfied go back to the main Fusion and just try to match the saturation to the saturation of the original HDRI. You do this by moving the blend ammount: the higher the blend ammount the less saturated the image, meaning it's more grey, the lower, the more juicy. We need to do this because the brightness contrast can make the image far too colourful and so this is how we compensate. for now we'll settle with a value of 80%.

Apply this material to the HDRI-sphere. The whole thing of putting it in a bhodiNUT Fusion and using brightness contrast just allows you to match it up to the background, whilst focusing your light sources as otherwise C4D over diffuses everything and you get too soft shadows etc.

Next we change the render settings. First, enable Radiosity. Then, switch off automatic lighting in the Render settings->Options. You may find that the resolution of the radiosity pass goes down a bit as a result of doing this, so the next thing to do is to up the accuracy of the radiosity in the render settings dialog box. You can also play around with the Max & Min samples to get a better image, as well as the Stochastic samples. With a little tweaking of the Saturation, Brightness Contrast and overall brightness of the luminosity channel you should be able to get a much more satisfactory HDRI style image in C4D.

And don't forget to visit Per-Anders' homepage!