hdri shadows-help!

[Matteo3d]

hello guys ,
I have to create render of products ,
I would use hdri for full illumination ,
hdri studio light ...
I did test it , I do not see shadows , hdri not produce shadows !
how to solve ?
thanks

[pegot]

I am not an expert but my understanding is that the strength and quality of the shadows produced by global illumination is highly dependent on how the HDR image was produced. Is it a true 32bit image with a full range of exposures to capture the sun? There is a tutorial I think I saw from a link in these forums which demonstrated in Photoshop the differences between a well formed HDR image with a full range of exposures vs. an HDR image with a more limited dynamic range.

Also does your scene contain anything for the main object to cast shadows on like a ground plain or a wall?

[Rikk The Gaijin]

You can paint higher values in the HDR map in Photoshop.

[face_off]

In HDR Light Studio, may the light small and very bright and you will get great shadows.

[FrankPooleFloating]

Expanding a little on what pegot said - in a good/proper hdri that has the sun present (even obscured by thin clouds) you should be able to crank the Image > Adjustments > Exposure down to negative high teens in PS (like -17 or so) when the sun starts to become invisible. HDRIs that are only made with a handful of exposures can not do this. If the sun disappears much sooner (before -10 or so), you have a shoddy, half-ass HDRI on your hands.

Edit: I just re-read your post... are you using HDR Light Studio OR do you have an HDRI which is an image of a studio lights?... The above is a good tip regardless -- but please confirm which you are lighting with.

[WhaleHunter]

Adjusting the gamma value on the HDRI will affect the contrast of the HDRI. This will either strengthen or soften any shadows.

[Matteo3d]

really tnx to all,
i use HDRI\image of a studio lights