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Re: Brand new way to kill hot pixels

Posted: Sat Jul 03, 2010 4:54 pm
by Chris_TC
Apart from the fact that hot pixel applications lose image detail (they don't replace the hot pixels by actual rendered samples), how about someone post one that can be used for animation.
radiance wrote:this is the 2x render technique, it's already done before a long time ago, if i remember correctly, a few years ago.
offcourse it's not fun having to render the image twice, although if you let them render each the same time and mix them 50/50 you will get 2x less noise.
No, you don't get 2x less noise, you get rid of practically all noise. That's what the blend mode "Darken" does, it only replaces the bright spots. And it FULLY replaces them, it's not a 50/50 mix.

Re: Brand new way to kill hot pixels

Posted: Sat Jul 03, 2010 5:03 pm
by n1k
This may be useful for frames of animation which turned out too noisy. You just re render those frames and merge them together.

Cheers,
n1k

Re: Brand new way to kill hot pixels

Posted: Sat Jul 03, 2010 5:22 pm
by sam75
radiance wrote:this is the 2x render technique, it's already done before a long time ago, if i remember correctly, a few years ago.
offcourse it's not fun having to render the image twice, although if you let them render each the same time and mix them 50/50 you will get 2x less noise.

Radiance
I tried this method but octane renders the exact same images, with fireflies and noise at the same place

Re: Brand new way to kill hot pixels

Posted: Sat Jul 03, 2010 7:27 pm
by sam75
I think I found it, I had to change rrprob to something higher than 0 which is the default setting for me, this is it ?

Supposed to be obvious ?

Re: Brand new way to kill hot pixels

Posted: Sat Jul 03, 2010 7:36 pm
by kivig
Done it... I think.
Chris_TC wrote:Apart from the fact that hot pixel applications lose image detail (they don't replace the hot pixels by actual rendered samples), how about someone post one that can be used for animation.
If we consider fireflies a defect not a detail, with this shouldn't lose any detail at all:
http://www.refractivesoftware.com/forum ... =21&t=2597

Re: Brand new way to kill hot pixels

Posted: Sat Jul 03, 2010 8:16 pm
by kubo
yeap, Proupin explained it very well here http://www.refractivesoftware.com/forum ... f=6&t=1773 and it's a good technique, but it does kill the fun to take the same shot several times even thou it's not much more time.

Re: Brand new way to kill hot pixels

Posted: Sat Jul 03, 2010 10:42 pm
by tomas_p
Hi all.

I use similar technic sometimes, but I don't use darken blending. I make in few steps 1 or 2 masks from combinations of this two renders. With this technique ist the residual hoise beter as if you use only darken and is posible use the 2-th render only with 10 percents of samples or both with 50 percents of desired samples.

If you will use two renders with the same kvality (50 percent of desired samples for both), paste these two renders in photoshop in two layers and make the upper invert and set te opacity at 50 percent. Merge these two layers and curent result ist the mask which I use for outmasking fireflies. Now paste these two renders one more in two layers and aply the mask for the upper. If are fireflies stil in the result, make the mask as invert.
Is posible ad the contrast for the mask for better result.

Re: Brand new way to kill hot pixels

Posted: Sat Jul 03, 2010 10:46 pm
by tomas_p
For other patern of noise i use the smal change in rayepsilion.

Re: Brand new way to kill hot pixels

Posted: Sat Jul 03, 2010 11:03 pm
by tomas_p
The litle imprecision of both these technics ( masking and darken blending ) is the fact that in very noisy parts of renders ist the result a bit darker as the corect result.

Re: Brand new way to kill hot pixels

Posted: Sat Jul 03, 2010 11:05 pm
by sam75
Radiance do you have any recommendation regarding the setting to change ? rrprob or rayeplsilon ?