Not enough Light?

Loony

Hi, I try to render a "darker" scene in the Basement, using tonemapping and some lightbulbs + very very less HDRI from tiny windows.

See my attachment, its in a over 9K Rendering and its still full of white particles.

 

How much iterations are needed ? :O It did first stopped the image because Quality Level 1, was not enough :/ Then it stopped because I forgot to increase the default timer (this render is resumed so its 4hours+), I think default timer is 7.800 Seconds I think its 2hours.

Not sure if the settings are high enough :/

I dont make much dark Renders, and for me it doesnt look that dark, but it seems like its too dark for the engine?

 

Richard Haseltine

You would probably do better with more light, then adjust the Tone Mapping settings to make it look dark.

Loony

I used the tonemappings from a other Basement scene, where a Ambient Preset was and it looked great :/

It's now at 11K iterations and... not much move visible :(

 

Loony

Thats how it looks when I not use CTRL+L (change Light preview) I assume, thats just... too dark xD

I canceld it now after 5-6Hours :(

Thats the tonemapping:

 

Thats how it should look, I think the light looks great :<

 

 

-----

I changed some light, this is the second room, behind the door:

My PC can not even clean the preview, so I assume its still too dark, but... its NOT dark O_o.

Lightbulbs.

Adjusted Tone mapping (shutter speed was extreme low).

 

 

Fishtales

Raise the ISO to 400, leave the F/stop and lower the Shutter Speed to 30.

Loony

Fishtales said:

Raise the ISO to 400, leave the F/stop and lower the Shutter Speed to 30.

 

Tooo bright :O

Fishtales

Now turn the Lumen down on the lights until you get the brightness you want.

Loony

Fishtales said:

Now turn the Lumen down on the lights until you get the brightness you want.

I will try it, but the preview also doesnt get clear, maybe... I should use Post denoiser on this image?

 

(Firefly Filter off)

Not even Postdenoiser can do it :(

I used your settings and I changed my Bulb from ~ 55.000Lumen to 1.500, but the Iray engine can not clean the scene :(

Not even with Post denoiser :(

Fishtales

Turn Firefly Filter to On. Underneath that set Nominal Luminance to 1500. Lower the Lumen on the lights to 150 and lower the F/stop to 4.

The render has only been running for 14 minutes and at 7% done is nowhere near finished.

You could also try lowering the Gloss on the walls to 1.0 or 2.0 and  lower the camera so that the light isn't in the image.

Loony

I did let the render run for over 1 hour I think, and it got not clean, I posted just a early screen.

Wall settings.

Lumen on Lamp on 150, Firefly with 1.500 enabled.

Glossy layer reduced but...

That looks not like it will render clean, the darkness will still be a problem :<

(I hate it when daz3d is stealing my time with problems Q_Q.... wanna make my comic :/ sometimes I wish I could draw)

Settings for the stairs wall:

I have an alternate option with a plane over the stairs to darken it, but I like the sun coming down.

The stairs seems to get clean, but not the dark "zone".

Loony

Splitted in 2 Parts, The stairs with the people will I do seperate, i would say it worked finally!

@Fishtales thanks for your time and help!

Fishtales

A couple of things you could do is Lower the Lumen on the lights a bit more, or raise the F/stop a bit say 6.0., or lower the lumen on the light shining down the stairs. For a low light area there is still a lot of hard shadows caused by the lights being too bright.

Loony

I placed around the corner an ambient light, that creates light, that did I use to solve the problem with too much darkness.

Richard Haseltine

if an image is taking a long time to converge then adjusting exposure or light levels will not do a llot to help - what you need is more lights, shining into the areas that are not currently gettign much direct light, then use Tone Mapping or post-render adjustments to get the contrast you want. Ghost lights are good for this as the don't add unwanted highlights, just flat light

Loony

Yeah the problem with more lights is... in my mind of "darkness" are "lamps" not the best instrument :D

Richard Haseltine

The thing is that Iray traces the path from light through to camera, or vice versa, varying the starting angle each time and seeing where the path ends up. If you have nooks and alcoves that are not directly lit then you are relying on the paths that bounce their way in, the more bounces it takes the more unlikely it will be that mutliple paths hit the surface which means it takes a long time for the colour to average out to the "final" value - some spots get bounces with a lot of energy and appear bright, others get only weak bounces or none and appear dark - which makes the area seem noisy. Using more lights to make sure that some fairly direct light gets everywhere helps to ensure that each pixel gets enough hits to reach a final value fairly quickly, at the expense of a less contrasty look so you need to adjust the exposure in the the render settings or afterwards in an editor (for which I'd use canvasses with a Beauty Pass to get an .exr, otherwise big tonal adjustments may introduce posterisation - banding - in the image)

Loony

Uff... a lot Knowledge, I will try to use bright scenes and make the darkness in Post progress.

Loony

I made a testrender with 2.000 iterations as start and it worked, it got clean, now did I let it run over Night and thought 8.000 is a good start because, the later the start is the more details are converted before the denoiser make it smooth.

But the denoiser did not trigger, that is not clean ;(

Was the render too long or why? @Richard Haseltine

Loony

Its NOT running on CPU, I did reduced the resolution from 4K to 2K, and changed first down to 2.000 Iterations start, now I changed to 700 Start iterations because for ~ 600+ Iterations did it Need ~ 2hours!

I will try to reinstall my driver, maybe that helps.

But weird why it say its out of memory and not using postdenoiser, when it is running on the cuda :/

" Iray [ERROR] - POST:RENDER ::   1.0   POST   rend error: A CUDA error occurred: out of memory"

I just got a new graphiccard but... *sigh*

Chohole

Please do remember that people use all sorts of devices to read the forums   and so set your images to dispaly at 800px on the forum.  Clicking on them will then bring them up to full size if the viewer wants

Loony

Hi, sometimes I do it, but the forum does also most times autofit it to the normal thread size.

Loony

I started a new try, 48Minutes are over, startpoint at 700iterations but... the denoiser doesnt start :( But also doesnt give out an error.

Btw. Is it possible to remove that iray optix thing? seems like daz studio doesnt like it, I have no idea where it is activated.

The Log didnt gave out an error but the scene did also not go clean.

Its so annoying, that it not works ;(

I reinstalled my driver and restarted the PC.

 

Richard Haseltine

The denoiser does require that the render is running on the GPU.

Loony

and that is happening, see my Taskmanager Screenshot over Choholes post.

Loony

@Fishtales and Richard

I amde it now how Richard it say with another Light source:

That are JUST 12 iterations! I did reset all Tonemappings, so with a Light Source who give "Real" Light in, does the engine work much better as with bright Tone Mapping settings.

I will Adjust Darkness later via Gimp.

I have to say its still very slow rendering,

weird, what is that "copy" thing? Normally is my "copy" on 0%. Like you can see at the Post with my last taskmanager screenshot.

It renders clean but too slow :/