HDRI too dark

Ruri

Hi,

Lets see if I'm doing this correctly

a) Get file from ,http://noemotionhdrs.net/hdrday.html, http://noemotionhdrs.net/hdrs/Day/06-07_Day_H.rar

b) Change the environment. The preview here are usually way darker than the pic given in any website.

c) Tone mapping settings are default. No additional lights in system

c) Preview or render. Results are very washed out.

My only expectation is the hdri dome should be more or less like the preview pics. Bumping the ISO or shutter speed will cause it to wash out, as expected.

Yes, I know some sites offer a highres jpg or a file with .hdr extension. I have tested both. Not mentioned above, but I have tested files from hdrlabs.com as well. I get more or less same effect.

I made sure to set the renders to default before providing the info above, let me know if there's anything you need me to check.

 

 

Padone

from what I see it seems the hdr map is not that hdr at all, so the sun value is low .. when I meet these issues in Blender I can easily add a gamma node to control the hdr image "intensity" .. but with DS I guess the right way to go is by tone mapping, I'd try exposure value 12 instead of the default 13 and see what happens .. hope this helps

SpottedKitty

Ruri said:

Yes, I know some sites offer a highres jpg or a file with .hdr extension.

Note that a .jpg image is not an HDRI file. The .jpg file format just doesn't allow for the extra data you need to have in an .hdr image. The large, high-res .hdr files are the proper ones to use as an environment light.

greymouser69

Actually the one the OP is using IS an hdr file and a pretty big one at around 350mb, I downloaded it and checked.  I haven't opened it in HDRShop to check anything else though.

Tobor

Set the dome as a Finite Sphere, and mess with the rotation so that the sun is behind the camera. Start with 180 degrees, then break it down into 45 degree chunks either side to see if things improve.

 

Ruri

@spottedkitty, greymouser: Yes, I tested with the .hdr file. I meant to say that when provided with both a .hdr and .jpg, usually I test both to see any difference.

 

@padone: Hi, ISO, shutter time and the exposure value is in direct relation to each other just like in camera, right? Normally I just give the ISO a small bump.

 

@tobor: Yup, I do give it a full rotate in iray preview mode, not much impact.

I have ok results with the pixar campus HDRI. Just want to understand how other HDRI works (mostly), are they all created equally, can the preview pic from website be trusted, or are there any information from the website that I can glean that gives me a 'should work in DS without massive tinkering' info.

Thanks for the feedback.

 

Tobor

The Pixar Campus HDRI should yield quite excellent results. It's very high definition with a clearly dileneated light source that produces a good shadow and direct light. That one was created properly; a lot of others (even ones you pay for) are junk. In many cases, they are provided only for the backdrop image, not for the lighting, even the ones (mislabeled) as an HDR or EXR.

On Tone Mapping, all you really need to adjust is Exposure Value, which represents the appropriate reciprocal of the other three, and is the value Iray is using to set the exposure. Shutter, ISO, and f/stop are just for show, and at least in the current D|S version, aren't connected to camera effects.  Because of habit, I tend to adjust the f/stop, as most of my automatic cameras have been aperture priority (not that Daz does automatic exposure).

Fishtales

Quite a few HDRI have a shadow spot right in the centre and it looks like this is one of them. With HDRI that do that I usually stick a Distant Light in for the sun and change the Temperature and Luminous Flux to get the light intensity and colour I want in the image. The HDRI then acts like a fill light giving ambient light to the shadows.