Playing with new stuff but...

[Hamfist]

Funny thing is I don't even know why I am putting so much effort into a render i'm not going to use for anything. it was literally just to see how the forest looked with a model in it and the flaws on the model bugged me so now i've spent like 6 hours dicking around with a render that has no purpose. LOL If nothing else I'm definitely stubborn.

 

[recreation]

nominal luminance is waaaayyyy to low, set it higher. I usually use 10k. Don't use exposure value and/or shutter speed, use film iso if anything. Turn caustic sampler off. Use a hdri instead of sunlight, most of the time hdri give more realistic light that sunlight (I know some people disagree). I'd also check if you took the 3dlight version instead of the iray one, just in case.
Who ever made this preset clearly had no idea what he was doing.

 

[Hamfist]

ok so what I did here was used their render settings and camera, except I reset the parameters you listed leaving all their other weird settings as is, and it came out clean. ? dont know if i learned anything or just confused myself more lol

 

[Hamfist]

the only thing that bugs me now is I didnt offset her from center in the render LOL.

nominal luminance is waaaayyyy to low, set it higher. I usually use 10k. Don't use exposure value and/or shutter speed, use film iso if anything. Turn caustic sampler off. Use a hdri instead of sunlight, most of the time hdri give more realistic light that sunlight (I know some people disagree). I'd also check if you took the 3dlight version instead of the iray one, just in case.
Who ever made this preset clearly had no idea what he was doing.

I'm downloading a bunch of HDRI right now. my selection is too limited. It's a really awesome forest and stream. The presets however are worth what I paid for it apparently (free) lol

 

[Hamfist]

turns out the scene is built too low I put an HDRI in and the HDRI cuts through the bottom lol I had to lift the entire scene and reset it so the HDRI ground doesnt show through.

 

[Lewdpanda95]

nominal luminance is waaaayyyy to low, set it higher. I usually use 10k.

As far as I know a value <= 0 just means the firefly filter won't do anything, with a high value of 10k you could just disable it too tbh.

The scene is very problematic in general. Many small lightsources as the sun shines trough the trees and foliage, which tends to create noise. Water tends to be noisy too. I found the best ways to handle those scenes is increasing the light, increase the resolution to scale it down later and just increasing the rendertime overall. Also post-denoiser is a must here.

 

[recreation]

As far as I know a value <= 0 just means the firefly filter won't do anything, with a high value of 10k you could just disable it too tbh.

The scene is very problematic in general. Many small lightsources as the sun shines trough the trees and foliage, which tends to create noise. Water tends to be noisy too. I found the best ways to handle those scenes is increasing the light, increase the resolution to scale it down later and just increasing the rendertime overall. Also post-denoiser is a must here.

-1 won't do anything, but it's -0.01. I'm actually not sure if it does anything, but better save then sorry.
10k isn't high, we're talking about luminecense here. Maybe you wanna read up what fireflies are and what the filter does to prevent them.

Also, there is only one light source in the scene, he uses sunlight -> one source, you can't even use other light sources if sunlight is active. The problem isn't many light sources (in this case), it's a lot of objects, and I'm not even sure it's the actual problem.
And please don't tell people that post denoizer is a must! It's never "a must". Optimizing a scene is much more important then relying on a denoizer. I've done way more complex scenes even before the Daz denoizer was introduced - without having noisy render!

 

[Lewdpanda95]

Also, there is only one light source in the scene, he uses sunlight -> one source, you can't even use other light sources if sunlight is active. The problem isn't many light sources (in this case), it's a lot of objects, and I'm not even sure it's the actual problem.

Yeah i meant the scenes is behaving as if we have many small lightsources. I thought it was clear by how I worded it. Apologies if it wasn't. What I want to say is that much of the visible surfaces only gets hit by indirect light, as the tress and foilage are in the path. Add refraction from the water and we have missing or wrong information about many pixels.

And please don't tell people that post denoizer is a must! It's never "a must". Optimizing a scene is much more important then relying on a denoizer.

Again I meant for this scene it is, not generally. And yes you could optimize it for example by adding more light into the scene with ghostlights, using a well lit hdri or by rotating the sun behind the character. But it would create different shadows and a different look. I agree I could have worded that clearer for the sake of giving advice to the OP. I would still use a post-denoiser at the last iterations in this scene tho.

Maybe you wanna read up what fireflies are and what the filter does to prevent them.

This is where I am dissappointed. Maybe you should take your own advice.

Excerpt from nvidea manual (for reference standard monitor luminance is around 150 cd / m²):
The nominal luminance is a hint to Iray Photoreal on what is considered a “reasonable” luminance level when viewing the scene. This luminance level is used internally to tune the firefly filter and error estimate. When the nominal luminance value is set to 0, Iray Photoreal will estimate the nominal luminance value from the tonemapper settings. If a user application applies its own tonemapping without using the built-in tonemappers, it is strongly advised to provide a nominal luminance.
Recommendations: For visualization, a reasonable nominal luminance would be the luminance value of a white color that maps to half the maximum brightness of the intended display device. For quantitative architectural daylight simulations (for example, calculating an irradiance buffer or irradiance probes), a reasonable nominal luminance could be the luminance of white paper under average day light.

On what we can agree is that the render settings in this package are garbage, lol.

 

[recreation]

Yeah i meant the scenes is behaving as if we have many small lightsources. I thought it was clear by how I worded it. Apologies if it wasn't. What I want to say is that much of the visible surfaces only gets hit by indirect light, as the tress and foilage are in the path. Add refraction from the water and we have missing or wrong information about many pixels.



Again I meant for this scene it is, not generally. And yes you could optimize it for example by adding more light into the scene with ghostlights, using a well lit hdri or by rotating the sun behind the character. But it would create different shadows and a different look. I agree I could have worded that clearer for the sake of giving advice to the OP. I would still use a post-denoiser at the last iterations in this scene tho.



This is where I am dissappointed. Maybe you should take your own advice.

Excerpt from nvidea manual (for reference standard monitor luminance is around 150 cd / m²):
The nominal luminance is a hint to Iray Photoreal on what is considered a “reasonable” luminance level when viewing the scene. This luminance level is used internally to tune the firefly filter and error estimate. When the nominal luminance value is set to 0, Iray Photoreal will estimate the nominal luminance value from the tonemapper settings. If a user application applies its own tonemapping without using the built-in tonemappers, it is strongly advised to provide a nominal luminance.
Recommendations: For visualization, a reasonable nominal luminance would be the luminance value of a white color that maps to half the maximum brightness of the intended display device. For quantitative architectural daylight simulations (for example, calculating an irradiance buffer or irradiance probes), a reasonable nominal luminance could be the luminance of white paper under average day light.

On what we can agree is that the render settings in this package are garbage, lol.

Wording is important, especially when you're talking to someone still quite new to the matter, it's no wonder that you find so many wrong information about rendering on the internet.
Sorry if my post sounds offensive, but I got slightly triggered by the amount of "wrong" (half true) informations. Think about it how someone new would take what you posted.

This is where I am dissappointed. Maybe you should take your own advice.

Welp, after looking for some nice reference I could quote, I have to admit that there isn't any to be found regarding Daz and iray... which, tbh I could have expected thinking about it now...
The problem is that your quote actually tells nothing about luminance, and it's also doing the same you did with your post, it's giving false/half true information in regards to render settings. They don't do anyone a favor by providing a monitor reference.
You can use this reference if you use the standard render settings, but then again, what's the point of using nominal luminance with the standard settings?
The answer is simple: it's not that simple!

Different scenes have different render settings, different render settings need different nominal luminance settings. Taking the render settings of the OP scene as an example (which is why I mentioned 10k in the first place), it has an exposure value of 9.5, which means that a fuckton of light will enter the camera, which also means you'll need a "high" nominal luminance value (if you use it), otherwise the scene will look washed out, because all the highlights will get filtered out.
Maybe 10k is overkill for the scene, I don't know, I don't have the scene, but let me give you an example of a render I'm working on right now:

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With this in mind, I could actually use lower values here, 5k for example, maybe even 1k and it would basically look the same, but imagine I'd used a sweaty body/reflective skin: all the shiny little details would simply not show up, because it would get filtered out (see how the shine on her arm disappearded?).
So like I said, 10k isn't really high, it depends on the scene and render settings, and let me be honest, the standard render settings are BS. You need to tweak them if you want to get good (better than average) results, and if you do that, you'll need "high" nominal luminance.

Hope this is understandable and clears things up.