What is an aceptable noise in renderings?

[Mister3d]

Hi quys, I'm not an architectural visualiser, so you know about this much more. I have a question about noise reduction in renderers regardless a specific renderer.

At what zoom distinct noise is unacceptable? I just thought it should dissapear completely, but looks like it's not possible at all: at 1600% zoom I can always see it. At best settings I manage that it slightly noticeable at 800%, at less it's not noticeable. So what is your zoom quality, that's to say?

Thank you.

[manta]

How do you see noise at 1600x, aren't you just looking at individual pixels...

[Mister3d]

How do you see noise at 1600x, aren't you just looking at individual pixels...

 

Yes, looks like I lost common sense. So at what resolution do you check noise?

[pailhead]

Native?

[Mister3d]

Native?

 

I mean noise which appears after raytracing, after glossy reflections mainly. Because if you make a gradient in Photoshop, it will be perfectly smooth when you zoom in, but if you make a glossy reflection it will be never smooth at large zooming. So as I understand removing moise is relative.

[louis.cho]

who will look at your work at 1600%

[BrianKitts]

The best answer to your question is no noise is acceptable unless you want noise... which artistically can be done. That being said....as long as your image is sized properly for how it's going to be printed 0 noise at 100% is the goal.

 

Anything beyond 100% and you are dealing with blowing up the image and printing larger than the native image....which brings you to the world of how large does an image need to be for oversize printing. That's a whole different world when something that you hold in your hand can be printed at 300dpi, but something on a billboard viewed from 50 meters away you can get away with 72dpi.

 

So evaluate how it's going to be printed, how far away is the image from the viewer and check out the threads on this forum about large prints to get your answer. Once your size is determined adjust the render settings to achieve your desired output.

[Mister3d]

Thank you, Brian. Well, this is very good explanation. 100% is the goal. One thing that seems to me that 3d visualisers look at some details closer than 100%, like antialiasing and noise, but sure only 100% matters if for monitor size, quite logical.

[colinsmith]

I think it would be worthwhile to have a close up look at a large resolution digital photo. Even a clean one has a lot of noise. Generally matching a render to a photo means various combinations of adding noise and bluring.....

[Mister3d]

I think it would be worthwhile to have a close up look at a large resolution digital photo. Even a clean one has a lot of noise. Generally matching a render to a photo means various combinations of adding noise and bluring.....

 

Yes, but matching digital footage to a film grain is made not with the noise from a renderer, but in post-production as far as I know, and there should be no noise in renderings themselves.

[colinsmith]

No, but there is less sense in spending a long time burning out grain, only to add a similar effect in post. If a slightly grainy render matches the photo.... then there is no problem, no?

The noise in the photo will also give you a good idea of what to aim for, as it is the standard the 3d will be judged against.

 

Noise also looks "worse" on screen, and when you print to photo paper I find it becomes less of a worry.

[Mister3d]

No, but there is less sense in spending a long time burning out grain, only to add a similar effect in post. If a slightly grainy render matches the photo.... then there is no problem, no?

The noise in the photo will also give you a good idea of what to aim for, as it is the standard the 3d will be judged against.

 

Noise also looks "worse" on screen, and when you print to photo paper I find it becomes less of a worry.

 

I found Christopher Nichols comment on this:

 

"Originally Posted by floze

Besides: I havent seen a completely noise free photograph yet, did you?

 

CNichols: Hold one... Photography grain is COMPLETELY different from render artifact grain. It all depends on the exposure, the film stoke, etc... Blues thend to be grainier, yada, yada... If you want photography grain, you add it in post. Never say... well the grain makes it look like a photograph. Not that I'm accusing you of doing that, just that people may see your post as such, which would be misleading."

[Devin Johnston]

It sounds like you want to have a debate about whether a render should have noise in it or not, there really isn't a debate to be had here since the answer can be yes or no. Take a look at these render engines Maxwell and Fry, virtually all the images these two render engines produce have some kind of noise in them. Noise isn't a bad thing and I find images that don't have any noise tend to look CG'ish and less realistic. You may be asking if a particular type of material like a blurry reflection should have noise in it, and I'd say no, but the over all image may have some noise which is kind of a different thing. In any case whether an image has noise or not is really only important to the person rendering the image and his client, if those people are happy with it then noting else matters.

[shaneis]

I mean noise which appears after raytracing, after glossy reflections mainly. Because if you make a gradient in Photoshop, it will be perfectly smooth when you zoom in, but if you make a glossy reflection it will be never smooth at large zooming. So as I understand removing moise is relative.

 

 

Noise is simply a rendering artifact. Should said noise be a result of under-sampling, then increased/over-sampling would be a good place to start. Should said noise be a result of low-res mapping, then higher res mapping would help. So yes, the "removal" of noise will be relative to the cause of said noise.

 

If you want your film to have an overall grain effect, it most certainly should be applied in post - applying it at render per frame would result in said noise flickering - another artifact.

 

So, if said noise is an artistic/ creative element, make renders clean and apply in post. If said noise is an undesirable artifact, apply changes relative to cause of said noise.