I don´t want to talk about mathematic, technic and function about HDRI. I will describe the practical use. An HDRI (High Dynmaic Range Image) is a shot from one image with different shutter speed. Every single image with all the different shutter speed were merged to one single image and saved as .hdr file. Years ago, the film industry recognized that this is a way to catch different levels of light, which is useful for rendering.

Which things are needed for using the HDRI-Technic ?

a) a digital cam
b) 3 spheres with a radius from 10 bis 30cm, and of it
- one silver, full reflective, mirroring sphere
- one white, matte sphere
- one grey, matte spherel
c) a tripod for your cam
d) a kind of tripod for your spheres
e) a white board
f) a little table
g) your laptop
h) the software HDR-Shop (download from Paul´s website www.debevec.org)
i) one free or for commercial use 3d software
j) a render

The following image shows all needed instruments for making the HDR Images.
Except the cam, we needed to make this photo.

point.a) Cam

If you have the choice you should choose a digital cam with remotecontrol. So you can connect your cam with your laptop. If you don´t have this feature, than it would be good to have a timer on your cam.

That´s important, because I could see, that you can get lot´s of distortions in your image, because your hand isn´t still enough for a longer shutter speed. Without that, it´s not possible to get a 100% sharp HDRI.


point.b) The spheres for the probes

The probes are nothing more than simply spheres you can get in every super market store. If you ask for spheres which you can use in the garden for your roses, than you are on the right way. I could also see, that you can use spheres you usualy find on christmas trees. In my case, I used simple spheres, which you can open. The core is hollow and not massive.

It is important that you will get three spheres, witht the same dimension and size, but with different materials and colors.

1. Sphere

It´s the mirror/reflection sphere and the material looks like a flat mirror. This sphere reflects the environment and you use this for the reflection probe.

2.+ 3. Sphere

One sphere should be white and the other one grey. The basic material should not reflect. An addition would be a black sphere, but with white and grey you will get great results.

point .c) The tripod

The tripod should fit to your cam. It´s important that not every easily gust of wind will blow your tripod away.


point t.d) The tripod for your spheres

This is a very creative point. A very good solution is a sunning screen, which are very cheap to get. And it´s important that you have a linkage or something like this. In this you can fit a round bar and fit the sphere on it.

point .e)

The white board will be used for the white alignment.

point .f)
A little table where you can put your laptop on, it´s really I can recommend.

pointt.g)
Your laptop with no more description. Hint: CPU + RAM is important for photo editing and render time.

point. h) HDR-SHOP
The HDR Shop you can download for non commercial use free from www.debevec.org. There are other software packages out you could use, but in this tutorial I will use HDR-SHOP only.

point.i) Free or for commercial use 3d software
As instance, Blender is a free software you could use. Other solutions are 3dsmax, Cinema 4D, Lightwave, Maya, Softimage, etc.


point.j) Render

Usually you will get with common 3d software packages render systems. But also you can get render plugins like Splutterfish Brazil or V-Ray from Chaosgroup.

an outstanding hint: a good background music - ELVIS will rock with you !!!
to give you the right motiviation. lol;